diff --git a/BomLocalService.csproj b/BomLocalService.csproj
index 48826b1..084858f 100644
--- a/BomLocalService.csproj
+++ b/BomLocalService.csproj
@@ -7,7 +7,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="9.0.11" />
     <PackageReference Include="Microsoft.Playwright" Version="1.57.0" />
   </ItemGroup>
 
diff --git a/Controllers/RadarController.cs b/Controllers/RadarController.cs
index 26078c9..e3fdd19 100644
--- a/Controllers/RadarController.cs
+++ b/Controllers/RadarController.cs
@@ -60,8 +60,19 @@ public class RadarController : ControllerBase
             {
                 // Get cache status to include in 404 response
                 // Use cache service directly since this is cache management, not radar-specific
-                var cacheExpirationMinutes = (int)_configuration.GetValue<double>("CacheExpirationMinutes", 15.5);
-                var cacheManagementCheckIntervalMinutes = _configuration.GetValue<int>("CacheManagement:CheckIntervalMinutes", 5);
+                var cacheExpirationMinutesConfig = _configuration.GetValue<double?>("CacheExpirationMinutes");
+                if (!cacheExpirationMinutesConfig.HasValue)
+                {
+                    throw new InvalidOperationException("CacheExpirationMinutes configuration is required. Set it in appsettings.json or via CACHEEXPIRATIONMINUTES environment variable.");
+                }
+                var cacheExpirationMinutes = (int)cacheExpirationMinutesConfig.Value;
+                
+                var cacheManagementCheckIntervalMinutesConfig = _configuration.GetValue<int?>("CacheManagement:CheckIntervalMinutes");
+                if (!cacheManagementCheckIntervalMinutesConfig.HasValue)
+                {
+                    throw new InvalidOperationException("CacheManagement:CheckIntervalMinutes configuration is required. Set it in appsettings.json or via CACHEMANAGEMENT__CHECKINTERVALMINUTES environment variable.");
+                }
+                var cacheManagementCheckIntervalMinutes = cacheManagementCheckIntervalMinutesConfig.Value;
                 var cacheStatus = await _cacheService.GetCacheStatusAsync(
                     suburb, 
                     state, 
@@ -288,7 +299,14 @@ public class RadarController : ControllerBase
 
             // Validate time range size to prevent excessive data loading
             // Default: base limit on cache retention, but allow override via config
-            var cacheRetentionHours = _configuration.GetValue<int>("CacheRetentionHours", 24);
+            var cacheRetentionHoursConfig = _configuration.GetValue<int?>("CacheRetentionHours");
+            if (!cacheRetentionHoursConfig.HasValue)
+            {
+                throw new InvalidOperationException("CacheRetentionHours configuration is required. Set it in appsettings.json or via CACHERETENTIONHOURS environment variable.");
+            }
+            var cacheRetentionHours = cacheRetentionHoursConfig.Value;
+            
+            // TimeSeries:MaxTimeRangeHours is optional (nullable)
             var configuredMaxHours = _configuration.GetValue<int?>("TimeSeries:MaxTimeRangeHours");
             
             // Use configured value if set, otherwise use cache retention (with minimum of 24 hours)
@@ -331,8 +349,19 @@ public class RadarController : ControllerBase
                 });
 
                 // Get cache status to include in 404 response
-                var cacheExpirationMinutes = (int)_configuration.GetValue<double>("CacheExpirationMinutes", 15.5);
-                var cacheManagementCheckIntervalMinutes = _configuration.GetValue<int>("CacheManagement:CheckIntervalMinutes", 5);
+                var cacheExpirationMinutesConfig = _configuration.GetValue<double?>("CacheExpirationMinutes");
+                if (!cacheExpirationMinutesConfig.HasValue)
+                {
+                    throw new InvalidOperationException("CacheExpirationMinutes configuration is required. Set it in appsettings.json or via CACHEEXPIRATIONMINUTES environment variable.");
+                }
+                var cacheExpirationMinutes = (int)cacheExpirationMinutesConfig.Value;
+                
+                var cacheManagementCheckIntervalMinutesConfig = _configuration.GetValue<int?>("CacheManagement:CheckIntervalMinutes");
+                if (!cacheManagementCheckIntervalMinutesConfig.HasValue)
+                {
+                    throw new InvalidOperationException("CacheManagement:CheckIntervalMinutes configuration is required. Set it in appsettings.json or via CACHEMANAGEMENT__CHECKINTERVALMINUTES environment variable.");
+                }
+                var cacheManagementCheckIntervalMinutes = cacheManagementCheckIntervalMinutesConfig.Value;
                 var cacheStatus = await _cacheService.GetCacheStatusAsync(
                     suburb, 
                     state, 
diff --git a/Program.cs b/Program.cs
index 966ed4b..008c276 100644
--- a/Program.cs
+++ b/Program.cs
@@ -14,39 +14,25 @@ var builder = WebApplication.CreateBuilder(args);
 // AddControllersWithViews includes AddControllers, so we use it for both MVC and API controllers
 builder.Services.AddControllersWithViews();
 builder.Services.AddEndpointsApiExplorer();
-builder.Services.AddOpenApi();
 builder.Services.AddHealthChecks();
 
 // Configure CORS - MUST be added before other services
-var corsOrigins = builder.Configuration.GetValue<string>("Cors:AllowedOrigins", "*");
-var corsMethods = builder.Configuration.GetValue<string>("Cors:AllowedMethods", "GET,POST,OPTIONS");
-var corsHeaders = builder.Configuration.GetValue<string>("Cors:AllowedHeaders", "*");
-var corsAllowCredentials = builder.Configuration.GetValue<bool>("Cors:AllowCredentials", false);
+// Configuration values come from appsettings.json (defaults) and can be overridden via environment variables
+// Environment variables use double underscore for nested keys (e.g., CORS__ALLOWEDORIGINS)
+var corsOrigins = builder.Configuration.GetValue<string>("Cors:AllowedOrigins")
+    ?? throw new InvalidOperationException("Cors:AllowedOrigins configuration is required. Set it in appsettings.json or via CORS__ALLOWEDORIGINS environment variable.");
+var corsMethods = builder.Configuration.GetValue<string>("Cors:AllowedMethods")
+    ?? throw new InvalidOperationException("Cors:AllowedMethods configuration is required. Set it in appsettings.json or via CORS__ALLOWEDMETHODS environment variable.");
+var corsHeaders = builder.Configuration.GetValue<string>("Cors:AllowedHeaders")
+    ?? throw new InvalidOperationException("Cors:AllowedHeaders configuration is required. Set it in appsettings.json or via CORS__ALLOWEDHEADERS environment variable.");
 
-// Support environment variable override (comma-separated for multiple origins)
-var corsOriginsEnv = Environment.GetEnvironmentVariable("CORS__ALLOWEDORIGINS");
-if (!string.IsNullOrEmpty(corsOriginsEnv))
+// For bool, check if the key exists in configuration (GetValue<bool> returns false if not found, which is ambiguous)
+var corsAllowCredentialsKey = builder.Configuration["Cors:AllowCredentials"];
+if (corsAllowCredentialsKey == null)
 {
-    corsOrigins = corsOriginsEnv;
-}
-
-var corsMethodsEnv = Environment.GetEnvironmentVariable("CORS__ALLOWEDMETHODS");
-if (!string.IsNullOrEmpty(corsMethodsEnv))
-{
-    corsMethods = corsMethodsEnv;
-}
-
-var corsHeadersEnv = Environment.GetEnvironmentVariable("CORS__ALLOWEDHEADERS");
-if (!string.IsNullOrEmpty(corsHeadersEnv))
-{
-    corsHeaders = corsHeadersEnv;
-}
-
-var corsAllowCredentialsEnv = Environment.GetEnvironmentVariable("CORS__ALLOWCREDENTIALS");
-if (!string.IsNullOrEmpty(corsAllowCredentialsEnv) && bool.TryParse(corsAllowCredentialsEnv, out var parsedCredentials))
-{
-    corsAllowCredentials = parsedCredentials;
+    throw new InvalidOperationException("Cors:AllowCredentials configuration is required. Set it in appsettings.json or via CORS__ALLOWCREDENTIALS environment variable.");
 }
+var corsAllowCredentials = builder.Configuration.GetValue<bool>("Cors:AllowCredentials");
 
 builder.Services.AddCors(options =>
 {
@@ -126,23 +112,12 @@ builder.Services.AddSingleton<IBomRadarService, BomLocalService.Services.BomRada
 builder.Services.AddHostedService<CacheCleanupService>();
 builder.Services.AddHostedService<CacheManagementService>();
 
-// Add configuration - appsettings.json provides default values
-// All values can be overridden via environment variables
-builder.Configuration.AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);
-
 var app = builder.Build();
 
 // Configure the HTTP request pipeline
-if (app.Environment.IsDevelopment())
-{
-    app.MapOpenApi();
-}
-
 // HTTPS redirection is optional and disabled by default for Docker flexibility
-// Users can enable it by setting ENABLE_HTTPS_REDIRECTION=true environment variable
-// or EnableHttpsRedirection=true in appsettings.json
-var enableHttpsRedirection = builder.Configuration.GetValue<bool>("EnableHttpsRedirection", false) ||
-                             Environment.GetEnvironmentVariable("ENABLE_HTTPS_REDIRECTION")?.Equals("true", StringComparison.OrdinalIgnoreCase) == true;
+// Users can enable it by setting EnableHttpsRedirection=true in appsettings.json or ENABLEHTTPSREDIRECTION=true environment variable
+var enableHttpsRedirection = builder.Configuration.GetValue<bool>("EnableHttpsRedirection", false);
 if (enableHttpsRedirection)
 {
     app.UseHttpsRedirection();
diff --git a/README.md b/README.md
index 1afc742..e8164ba 100644
--- a/README.md
+++ b/README.md
@@ -218,7 +218,7 @@ All configuration can be done via environment variables, which override the defa
 |----------|-------------|---------|
 | `ASPNETCORE_ENVIRONMENT` | Runtime environment (Development/Production) | `Production` |
 | `ASPNETCORE_URLS` | URLs the service listens on | `http://+:8080` |
-| `ENABLE_HTTPS_REDIRECTION` | Enable HTTPS redirection | `false` |
+| `ENABLEHTTPSREDIRECTION` | Enable HTTPS redirection | `false` |
 
 #### Application Configuration
 
@@ -235,8 +235,7 @@ All configuration can be done via environment variables, which override the defa
 |----------|-------------|---------|---------|
 | `CACHEMANAGEMENT__CHECKINTERVALMINUTES` | Interval between cache validity checks | `5` | `10` |
 | `CACHEMANAGEMENT__INITIALDELAYSECONDS` | Delay before first cache check on startup | `10` | `30` |
-| `CACHEMANAGEMENT__UPDATESTAGGERSECONDS` | Delay between triggering cache updates | `2` | `5` |
-| `CACHEMANAGEMENT__LOCATIONSTAGGERSECONDS` | Delay between processing different locations | `1` | `2` |
+| `CACHEMANAGEMENT__LOCATIONSTAGGERSECONDS` | Delay between processing different locations (used for both initial and periodic updates) | `1` | `2` |
 
 #### Cache Cleanup
 
@@ -880,13 +879,6 @@ DELETE /api/cache/{suburb}/{state}
 }
 ```
 
-### OpenAPI Documentation
-
-When running in Development mode, OpenAPI documentation is available at:
-```
-http://localhost:8082/openapi/v1.json
-```
-
 ## Cache Update Estimation
 
 The service uses a **metrics-based estimation system** to provide accurate estimates of cache update completion times. This ensures clients receive meaningful `nextUpdateTime` values that adapt to the actual hardware performance.
diff --git a/Services/BomRadarService.cs b/Services/BomRadarService.cs
index 34ebb81..6784d52 100644
--- a/Services/BomRadarService.cs
+++ b/Services/BomRadarService.cs
@@ -32,9 +32,27 @@ public class BomRadarService : IBomRadarService, IDisposable
         _scrapingService = scrapingService;
         _debugService = debugService;
         _configuration = configuration;
-        _cacheExpirationMinutes = configuration.GetValue<double>("CacheExpirationMinutes", 12.5);
-        _cacheManagementCheckIntervalMinutes = configuration.GetValue<int>("CacheManagement:CheckIntervalMinutes", 5);
-        _timeSeriesWarningFolderCount = configuration.GetValue<int>("TimeSeries:WarningFolderCount", 200);
+        
+        var cacheExpirationMinutesConfig = configuration.GetValue<double?>("CacheExpirationMinutes");
+        if (!cacheExpirationMinutesConfig.HasValue)
+        {
+            throw new InvalidOperationException("CacheExpirationMinutes configuration is required. Set it in appsettings.json or via CACHEEXPIRATIONMINUTES environment variable.");
+        }
+        _cacheExpirationMinutes = cacheExpirationMinutesConfig.Value;
+        
+        var cacheManagementCheckIntervalMinutesConfig = configuration.GetValue<int?>("CacheManagement:CheckIntervalMinutes");
+        if (!cacheManagementCheckIntervalMinutesConfig.HasValue)
+        {
+            throw new InvalidOperationException("CacheManagement:CheckIntervalMinutes configuration is required. Set it in appsettings.json or via CACHEMANAGEMENT__CHECKINTERVALMINUTES environment variable.");
+        }
+        _cacheManagementCheckIntervalMinutes = cacheManagementCheckIntervalMinutesConfig.Value;
+        
+        var timeSeriesWarningFolderCountConfig = configuration.GetValue<int?>("TimeSeries:WarningFolderCount");
+        if (!timeSeriesWarningFolderCountConfig.HasValue)
+        {
+            throw new InvalidOperationException("TimeSeries:WarningFolderCount configuration is required. Set it in appsettings.json or via TIMESERIES__WARNINGFOLDERCOUNT environment variable.");
+        }
+        _timeSeriesWarningFolderCount = timeSeriesWarningFolderCountConfig.Value;
         
         // Calculate estimated cache update duration
         _estimatedUpdateDurationSeconds = CacheHelper.GetEstimatedUpdateDurationSeconds(configuration, CachedDataType.Radar);
diff --git a/Services/BrowserService.cs b/Services/BrowserService.cs
index 715ffca..e13d75c 100644
--- a/Services/BrowserService.cs
+++ b/Services/BrowserService.cs
@@ -15,7 +15,15 @@ public class BrowserService : IBrowserService
     public BrowserService(ILogger<BrowserService> logger, IConfiguration configuration, IDebugService debugService)
     {
         _logger = logger;
-        _timezone = configuration.GetValue<string>("Timezone") ?? "Australia/Brisbane";
+        // Get timezone from configuration (default from appsettings.json, can be overridden via TIMEZONE environment variable)
+        var timezone = configuration.GetValue<string>("Timezone");
+        
+        if (string.IsNullOrEmpty(timezone))
+        {
+            throw new InvalidOperationException("Timezone configuration is required. Set it in appsettings.json or via TIMEZONE environment variable.");
+        }
+        
+        _timezone = timezone;
         _debugService = debugService;
     }
 
diff --git a/Services/CacheCleanupService.cs b/Services/CacheCleanupService.cs
index 2b2d2e8..678ad37 100644
--- a/Services/CacheCleanupService.cs
+++ b/Services/CacheCleanupService.cs
@@ -14,8 +14,20 @@ public class CacheCleanupService : BackgroundService
     {
         _logger = logger;
         _cacheDirectory = FilePathHelper.GetCacheDirectory(configuration);
-        _retentionHours = configuration.GetValue<int>("CacheRetentionHours", 24);
-        var cleanupIntervalHours = configuration.GetValue<int>("CacheCleanup:IntervalHours", 1);
+        
+        var retentionHoursConfig = configuration.GetValue<int?>("CacheRetentionHours");
+        if (!retentionHoursConfig.HasValue)
+        {
+            throw new InvalidOperationException("CacheRetentionHours configuration is required. Set it in appsettings.json or via CACHERETENTIONHOURS environment variable.");
+        }
+        _retentionHours = retentionHoursConfig.Value;
+        
+        var cleanupIntervalHoursConfig = configuration.GetValue<int?>("CacheCleanup:IntervalHours");
+        if (!cleanupIntervalHoursConfig.HasValue)
+        {
+            throw new InvalidOperationException("CacheCleanup:IntervalHours configuration is required. Set it in appsettings.json or via CACHECLEANUP__INTERVALHOURS environment variable.");
+        }
+        var cleanupIntervalHours = cleanupIntervalHoursConfig.Value;
         _cleanupInterval = TimeSpan.FromHours(cleanupIntervalHours);
     }
 
diff --git a/Services/CacheManagementService.cs b/Services/CacheManagementService.cs
index 59392e5..851d767 100644
--- a/Services/CacheManagementService.cs
+++ b/Services/CacheManagementService.cs
@@ -11,6 +11,8 @@ public class CacheManagementService : BackgroundService
     private readonly IBrowserService _browserService;
     private readonly IConfiguration _configuration;
     private readonly TimeSpan _checkInterval;
+    private readonly TimeSpan _locationStaggerInterval;
+    private readonly TimeSpan _initialDelayInterval;
     private readonly HashSet<string> _activeUpdates = new();
     private readonly object _lock = new();
 
@@ -24,14 +26,34 @@ public class CacheManagementService : BackgroundService
         _bomRadarService = bomRadarService;
         _browserService = browserService;
         _configuration = configuration;
-        var checkIntervalMinutes = configuration.GetValue<int>("CacheManagement:CheckIntervalMinutes", 5);
+        
+        var checkIntervalMinutesConfig = configuration.GetValue<int?>("CacheManagement:CheckIntervalMinutes");
+        if (!checkIntervalMinutesConfig.HasValue)
+        {
+            throw new InvalidOperationException("CacheManagement:CheckIntervalMinutes configuration is required. Set it in appsettings.json or via CACHEMANAGEMENT__CHECKINTERVALMINUTES environment variable.");
+        }
+        var checkIntervalMinutes = checkIntervalMinutesConfig.Value;
         
         if (checkIntervalMinutes <= 0 || checkIntervalMinutes > 60)
         {
             throw new ArgumentException("CacheManagement:CheckIntervalMinutes must be between 1 and 60", nameof(configuration));
         }
-        
         _checkInterval = TimeSpan.FromMinutes(checkIntervalMinutes);
+        
+        // LocationStaggerSeconds is used for delays between processing locations (both initial and periodic)
+        var locationStaggerSecondsConfig = configuration.GetValue<int?>("CacheManagement:LocationStaggerSeconds");
+        if (!locationStaggerSecondsConfig.HasValue)
+        {
+            throw new InvalidOperationException("CacheManagement:LocationStaggerSeconds configuration is required. Set it in appsettings.json or via CACHEMANAGEMENT__LOCATIONSTAGGERSECONDS environment variable.");
+        }
+        _locationStaggerInterval = TimeSpan.FromSeconds(locationStaggerSecondsConfig.Value);
+        
+        var initialDelaySecondsConfig = configuration.GetValue<int?>("CacheManagement:InitialDelaySeconds");
+        if (!initialDelaySecondsConfig.HasValue)
+        {
+            throw new InvalidOperationException("CacheManagement:InitialDelaySeconds configuration is required. Set it in appsettings.json or via CACHEMANAGEMENT__INITIALDELAYSECONDS environment variable.");
+        }
+        _initialDelayInterval = TimeSpan.FromSeconds(initialDelaySecondsConfig.Value);
     }
 
     protected override async Task ExecuteAsync(CancellationToken stoppingToken)
@@ -39,8 +61,7 @@ public class CacheManagementService : BackgroundService
         _logger.LogInformation("Cache management service started. Check interval: {Interval}", _checkInterval);
 
         // Wait a bit for the service to fully initialize
-        var initialDelaySeconds = _configuration.GetValue<int>("CacheManagement:InitialDelaySeconds", 10);
-        await Task.Delay(TimeSpan.FromSeconds(initialDelaySeconds), stoppingToken);
+        await Task.Delay(_initialDelayInterval, stoppingToken);
 
         // Pre-warm the browser before starting cache updates
         _logger.LogInformation("Pre-warming browser before cache updates");
@@ -58,28 +79,7 @@ public class CacheManagementService : BackgroundService
 
         // Initial cache update on startup
         _logger.LogInformation("Performing initial cache update for {Count} locations", locationsToManage.Count);
-        int initialUpdatesTriggered = 0;
-        int initialCachesValid = 0;
-        
-        foreach (var (suburb, state) in locationsToManage)
-        {
-            if (stoppingToken.IsCancellationRequested)
-                break;
-
-            var (triggered, isValid) = await UpdateCacheIfNeededAsync(suburb, state, stoppingToken);
-            if (triggered)
-            {
-                initialUpdatesTriggered++;
-            }
-            else if (isValid)
-            {
-                initialCachesValid++;
-            }
-
-            // Stagger updates to avoid overwhelming the system
-            var updateStaggerSeconds = _configuration.GetValue<int>("CacheManagement:UpdateStaggerSeconds", 2);
-            await Task.Delay(TimeSpan.FromSeconds(updateStaggerSeconds), stoppingToken);
-        }
+        var (initialUpdatesTriggered, initialCachesValid) = await ProcessLocationsAsync(locationsToManage, stoppingToken);
         
         _logger.LogInformation("Initial cache update completed: {UpdatesTriggered} updates triggered, {CachesValid} caches valid", 
             initialUpdatesTriggered, initialCachesValid);
@@ -95,28 +95,7 @@ public class CacheManagementService : BackgroundService
                 locationsToManage = GetLocationsToManage();
                 _logger.LogInformation("Starting periodic cache check for {Count} locations", locationsToManage.Count);
 
-                int updatesTriggered = 0;
-                int cachesValid = 0;
-
-                foreach (var (suburb, state) in locationsToManage)
-                {
-                    if (stoppingToken.IsCancellationRequested)
-                        break;
-
-                    var (triggered, isValid) = await UpdateCacheIfNeededAsync(suburb, state, stoppingToken);
-                    if (triggered)
-                    {
-                        updatesTriggered++;
-                    }
-                    else if (isValid)
-                    {
-                        cachesValid++;
-                    }
-
-                    // Small delay between locations
-                    var locationStaggerSeconds = _configuration.GetValue<int>("CacheManagement:LocationStaggerSeconds", 1);
-                    await Task.Delay(TimeSpan.FromSeconds(locationStaggerSeconds), stoppingToken);
-                }
+                var (updatesTriggered, cachesValid) = await ProcessLocationsAsync(locationsToManage, stoppingToken);
 
                 _logger.LogInformation("Periodic cache check completed: {UpdatesTriggered} updates triggered, {CachesValid} caches valid", 
                     updatesTriggered, cachesValid);
@@ -128,6 +107,38 @@ public class CacheManagementService : BackgroundService
         }
     }
 
+    /// <summary>
+    /// Processes a list of locations, checking and updating cache as needed
+    /// </summary>
+    private async Task<(int updatesTriggered, int cachesValid)> ProcessLocationsAsync(
+        List<(string suburb, string state)> locations, 
+        CancellationToken cancellationToken)
+    {
+        int updatesTriggered = 0;
+        int cachesValid = 0;
+
+        foreach (var (suburb, state) in locations)
+        {
+            if (cancellationToken.IsCancellationRequested)
+                break;
+
+            var (triggered, isValid) = await UpdateCacheIfNeededAsync(suburb, state, cancellationToken);
+            if (triggered)
+            {
+                updatesTriggered++;
+            }
+            else if (isValid)
+            {
+                cachesValid++;
+            }
+
+            // Stagger processing to avoid overwhelming the system
+            await Task.Delay(_locationStaggerInterval, cancellationToken);
+        }
+
+        return (updatesTriggered, cachesValid);
+    }
+
     private async Task<(bool updateTriggered, bool isValid)> UpdateCacheIfNeededAsync(string suburb, string state, CancellationToken cancellationToken)
     {
         var locationKey = LocationHelper.GetLocationKey(suburb, state);
diff --git a/Services/CacheService.cs b/Services/CacheService.cs
index 8f8a944..0d7f3be 100644
--- a/Services/CacheService.cs
+++ b/Services/CacheService.cs
@@ -27,7 +27,13 @@ public class CacheService : ICacheService
         _logger = logger;
         _configuration = configuration;
         _cacheDirectory = FilePathHelper.GetCacheDirectory(configuration);
-        _cacheExpirationMinutes = configuration.GetValue<double>("CacheExpirationMinutes", 12.5);
+        
+        var cacheExpirationMinutesConfig = configuration.GetValue<double?>("CacheExpirationMinutes");
+        if (!cacheExpirationMinutesConfig.HasValue)
+        {
+            throw new InvalidOperationException("CacheExpirationMinutes configuration is required. Set it in appsettings.json or via CACHEEXPIRATIONMINUTES environment variable.");
+        }
+        _cacheExpirationMinutes = cacheExpirationMinutesConfig.Value;
         
         if (_cacheExpirationMinutes <= 0)
         {
diff --git a/Services/DebugService.cs b/Services/DebugService.cs
index 238a434..f27b757 100644
--- a/Services/DebugService.cs
+++ b/Services/DebugService.cs
@@ -14,20 +14,17 @@ namespace BomLocalService.Services;
         public DebugService(ILogger<DebugService> logger, IConfiguration configuration)
         {
             _logger = logger;
-            _waitMs = configuration.GetValue<int>("Debug:WaitMs", 2000);
+            
+            var waitMsConfig = configuration.GetValue<int?>("Debug:WaitMs");
+            if (!waitMsConfig.HasValue)
+            {
+                throw new InvalidOperationException("Debug:WaitMs configuration is required. Set it in appsettings.json or via DEBUG__WAITMS environment variable.");
+            }
+            _waitMs = waitMsConfig.Value;
         
-        // Check all possible ways the config might be set
-        var debugEnabledEnv = Environment.GetEnvironmentVariable("DEBUG__ENABLED");
-        var debugEnabledConfig = configuration.GetValue<bool>("Debug:Enabled", false);
-        var debugEnabledFromConfig = configuration["Debug:Enabled"];
-        
-        _logger.LogInformation("Debug configuration check - Env var DEBUG__ENABLED: {EnvVar}, Config Debug:Enabled: {ConfigValue}, Config string: {ConfigString}", 
-            debugEnabledEnv ?? "null", debugEnabledConfig, debugEnabledFromConfig ?? "null");
-        
-        // Try environment variable first, then config
-        _enabled = !string.IsNullOrEmpty(debugEnabledEnv) 
-            ? bool.TryParse(debugEnabledEnv, out var envBool) && envBool
-            : debugEnabledConfig;
+        // Get debug enabled from configuration (default from appsettings.json, can be overridden via DEBUG__ENABLED environment variable)
+        // Note: bool defaults to false if not found, which is acceptable for Debug:Enabled
+        _enabled = configuration.GetValue<bool>("Debug:Enabled", false);
         
         var cacheDirectory = FilePathHelper.GetCacheDirectory(configuration);
         _debugDirectory = Path.Combine(cacheDirectory, "debug");
diff --git a/Services/Scraping/Steps/Capture/CaptureFramesStep.cs b/Services/Scraping/Steps/Capture/CaptureFramesStep.cs
index 68a8ffe..e4f95b7 100644
--- a/Services/Scraping/Steps/Capture/CaptureFramesStep.cs
+++ b/Services/Scraping/Steps/Capture/CaptureFramesStep.cs
@@ -25,15 +25,38 @@ public class CaptureFramesStep : BaseScrapingStep
         : base(logger, selectorService, debugService, configuration)
     {
         _cacheService = cacheService;
-        _tileRenderWaitMs = configuration.GetValue<int>("Screenshot:TileRenderWaitMs", 5000);
+        
+        var tileRenderWaitMsConfig = configuration.GetValue<int?>("Screenshot:TileRenderWaitMs");
+        if (!tileRenderWaitMsConfig.HasValue)
+        {
+            throw new InvalidOperationException("Screenshot:TileRenderWaitMs configuration is required. Set it in appsettings.json or via SCREENSHOT__TILERENDERWAITMS environment variable.");
+        }
+        _tileRenderWaitMs = tileRenderWaitMsConfig.Value;
         
         var cropSection = configuration.GetSection("Screenshot:Crop");
+        
+        var cropXConfig = cropSection.GetValue<int?>("X");
+        if (!cropXConfig.HasValue)
+        {
+            throw new InvalidOperationException("Screenshot:Crop:X configuration is required. Set it in appsettings.json or via SCREENSHOT__CROP__X environment variable.");
+        }
+        var cropYConfig = cropSection.GetValue<int?>("Y");
+        if (!cropYConfig.HasValue)
+        {
+            throw new InvalidOperationException("Screenshot:Crop:Y configuration is required. Set it in appsettings.json or via SCREENSHOT__CROP__Y environment variable.");
+        }
+        var cropRightOffsetConfig = cropSection.GetValue<int?>("RightOffset");
+        if (!cropRightOffsetConfig.HasValue)
+        {
+            throw new InvalidOperationException("Screenshot:Crop:RightOffset configuration is required. Set it in appsettings.json or via SCREENSHOT__CROP__RIGHTOFFSET environment variable.");
+        }
+        
         _cropConfig = new ScreenshotCropConfig
         {
-            X = cropSection.GetValue<int>("X", 0),
-            Y = cropSection.GetValue<int>("Y", 0),
-            RightOffset = cropSection.GetValue<int>("RightOffset", 0),
-            Height = cropSection.GetValue<int?>("Height")
+            X = cropXConfig.Value,
+            Y = cropYConfig.Value,
+            RightOffset = cropRightOffsetConfig.Value,
+            Height = cropSection.GetValue<int?>("Height") // Height is optional (nullable)
         };
     }
     
diff --git a/Services/Scraping/Steps/Map/ResetToFirstFrameStep.cs b/Services/Scraping/Steps/Map/ResetToFirstFrameStep.cs
index 1fa356c..9a99a48 100644
--- a/Services/Scraping/Steps/Map/ResetToFirstFrameStep.cs
+++ b/Services/Scraping/Steps/Map/ResetToFirstFrameStep.cs
@@ -86,7 +86,12 @@ public class ResetToFirstFrameStep : BaseScrapingStep
             await SaveDebugAsync(context, 10, "scrubber_at_position_0", cancellationToken);
             
             // Wait for frame 0 tiles to fully render
-            var tileRenderWaitMs = Configuration.GetValue<int>("Screenshot:TileRenderWaitMs", 5000);
+            var tileRenderWaitMsConfig = Configuration.GetValue<int?>("Screenshot:TileRenderWaitMs");
+            if (!tileRenderWaitMsConfig.HasValue)
+            {
+                throw new InvalidOperationException("Screenshot:TileRenderWaitMs configuration is required. Set it in appsettings.json or via SCREENSHOT__TILERENDERWAITMS environment variable.");
+            }
+            var tileRenderWaitMs = tileRenderWaitMsConfig.Value;
             await context.Page.WaitForTimeoutAsync(tileRenderWaitMs);
             
             context.CurrentState = PageState.Frame0Selected;
diff --git a/Services/Scraping/Steps/Map/WaitForMapReadyStep.cs b/Services/Scraping/Steps/Map/WaitForMapReadyStep.cs
index d83a73d..6e77cda 100644
--- a/Services/Scraping/Steps/Map/WaitForMapReadyStep.cs
+++ b/Services/Scraping/Steps/Map/WaitForMapReadyStep.cs
@@ -18,7 +18,12 @@ public class WaitForMapReadyStep : BaseScrapingStep
         IConfiguration configuration)
         : base(logger, selectorService, debugService, configuration)
     {
-        _tileRenderWaitMs = configuration.GetValue<int>("Screenshot:TileRenderWaitMs", 5000);
+        var tileRenderWaitMsConfig = configuration.GetValue<int?>("Screenshot:TileRenderWaitMs");
+        if (!tileRenderWaitMsConfig.HasValue)
+        {
+            throw new InvalidOperationException("Screenshot:TileRenderWaitMs configuration is required. Set it in appsettings.json or via SCREENSHOT__TILERENDERWAITMS environment variable.");
+        }
+        _tileRenderWaitMs = tileRenderWaitMsConfig.Value;
     }
     
     public override bool CanExecute(ScrapingContext context)
diff --git a/Services/Scraping/Steps/Navigation/NavigateHomepageStep.cs b/Services/Scraping/Steps/Navigation/NavigateHomepageStep.cs
index 85a36fa..a12fc20 100644
--- a/Services/Scraping/Steps/Navigation/NavigateHomepageStep.cs
+++ b/Services/Scraping/Steps/Navigation/NavigateHomepageStep.cs
@@ -18,7 +18,8 @@ public class NavigateHomepageStep : BaseScrapingStep
         IConfiguration configuration)
         : base(logger, selectorService, debugService, configuration)
     {
-        _baseUrl = configuration.GetValue<string>("Scraping:BaseUrl") ?? "https://www.bom.gov.au/";
+        _baseUrl = configuration.GetValue<string>("Scraping:BaseUrl")
+            ?? throw new InvalidOperationException("Scraping:BaseUrl configuration is required. Set it in appsettings.json or via SCRAPING__BASEURL environment variable.");
     }
     
     public override bool CanExecute(ScrapingContext context)
diff --git a/Services/Scraping/Steps/Search/SelectSearchResultStep.cs b/Services/Scraping/Steps/Search/SelectSearchResultStep.cs
index 433d431..1733ec1 100644
--- a/Services/Scraping/Steps/Search/SelectSearchResultStep.cs
+++ b/Services/Scraping/Steps/Search/SelectSearchResultStep.cs
@@ -174,7 +174,12 @@ public class SelectSearchResultStep : BaseScrapingStep
             
             // Wait for forecast page to load
             await context.Page.WaitForLoadStateAsync(LoadState.DOMContentLoaded, new PageWaitForLoadStateOptions { Timeout = 15000 });
-            var dynamicContentWaitMs = Configuration.GetValue<int>("Screenshot:DynamicContentWaitMs", 2000);
+            var dynamicContentWaitMsConfig = Configuration.GetValue<int?>("Screenshot:DynamicContentWaitMs");
+            if (!dynamicContentWaitMsConfig.HasValue)
+            {
+                throw new InvalidOperationException("Screenshot:DynamicContentWaitMs configuration is required. Set it in appsettings.json or via SCREENSHOT__DYNAMICCONTENTWAITMS environment variable.");
+            }
+            var dynamicContentWaitMs = dynamicContentWaitMsConfig.Value;
             await context.Page.WaitForTimeoutAsync(dynamicContentWaitMs);
             await SaveDebugAsync(context, 5, "forecast_page_loaded", cancellationToken);
             
diff --git a/Services/Scraping/Workflows/RadarScrapingWorkflow.cs b/Services/Scraping/Workflows/RadarScrapingWorkflow.cs
index 4358746..42449bf 100644
--- a/Services/Scraping/Workflows/RadarScrapingWorkflow.cs
+++ b/Services/Scraping/Workflows/RadarScrapingWorkflow.cs
@@ -44,8 +44,20 @@ public class RadarScrapingWorkflow : IWorkflow<RadarResponse>
         _stepRegistry = stepRegistry;
         _configuration = configuration;
         _cacheService = cacheService;
-        _cacheExpirationMinutes = configuration.GetValue<double>("CacheExpirationMinutes", 12.5);
-        _cacheManagementCheckIntervalMinutes = configuration.GetValue<int>("CacheManagement:CheckIntervalMinutes", 5);
+        
+        var cacheExpirationMinutesConfig = configuration.GetValue<double?>("CacheExpirationMinutes");
+        if (!cacheExpirationMinutesConfig.HasValue)
+        {
+            throw new InvalidOperationException("CacheExpirationMinutes configuration is required. Set it in appsettings.json or via CACHEEXPIRATIONMINUTES environment variable.");
+        }
+        _cacheExpirationMinutes = cacheExpirationMinutesConfig.Value;
+        
+        var cacheManagementCheckIntervalMinutesConfig = configuration.GetValue<int?>("CacheManagement:CheckIntervalMinutes");
+        if (!cacheManagementCheckIntervalMinutesConfig.HasValue)
+        {
+            throw new InvalidOperationException("CacheManagement:CheckIntervalMinutes configuration is required. Set it in appsettings.json or via CACHEMANAGEMENT__CHECKINTERVALMINUTES environment variable.");
+        }
+        _cacheManagementCheckIntervalMinutes = cacheManagementCheckIntervalMinutesConfig.Value;
     }
     
     public async Task<RadarResponse> ExecuteAsync(ScrapingContext context, CancellationToken cancellationToken)
diff --git a/Services/TimeParsingService.cs b/Services/TimeParsingService.cs
index f1c99dc..508a9e6 100644
--- a/Services/TimeParsingService.cs
+++ b/Services/TimeParsingService.cs
@@ -14,7 +14,13 @@ public class TimeParsingService : ITimeParsingService
     public TimeParsingService(ILogger<TimeParsingService> logger, IConfiguration configuration)
     {
         _logger = logger;
-        var timezone = configuration.GetValue<string>("Timezone") ?? "Australia/Brisbane";
+        // Get timezone from configuration (default from appsettings.json, can be overridden via TIMEZONE environment variable)
+        var timezone = configuration.GetValue<string>("Timezone");
+        
+        if (string.IsNullOrEmpty(timezone))
+        {
+            throw new InvalidOperationException("Timezone configuration is required. Set it in appsettings.json or via TIMEZONE environment variable.");
+        }
         
         try
         {
@@ -23,8 +29,8 @@ public class TimeParsingService : ITimeParsingService
         }
         catch (TimeZoneNotFoundException)
         {
-            _logger.LogWarning("Timezone {Timezone} not found, defaulting to Australia/Brisbane", timezone);
-            _timeZoneInfo = TimeZoneInfo.FindSystemTimeZoneById("Australia/Brisbane");
+            _logger.LogError("Timezone {Timezone} not found. Please use a valid IANA timezone identifier.", timezone);
+            throw new InvalidOperationException($"Invalid timezone '{timezone}'. Please use a valid IANA timezone identifier (e.g., Australia/Sydney, Australia/Brisbane).");
         }
     }
 
diff --git a/Utilities/CacheHelper.cs b/Utilities/CacheHelper.cs
index e6a6648..2395d27 100644
--- a/Utilities/CacheHelper.cs
+++ b/Utilities/CacheHelper.cs
@@ -14,8 +14,12 @@ public static class CacheHelper
     public static int GetFrameCountForDataType(IConfiguration configuration, CachedDataType dataType)
     {
         var dataTypeName = dataType.ToString();
-        var frameCount = configuration.GetValue<int>($"CachedDataTypes:{dataTypeName}:FrameCount", 7);
-        return frameCount;
+        var frameCountConfig = configuration.GetValue<int?>($"CachedDataTypes:{dataTypeName}:FrameCount");
+        if (!frameCountConfig.HasValue)
+        {
+            throw new InvalidOperationException($"CachedDataTypes:{dataTypeName}:FrameCount configuration is required. Set it in appsettings.json or via CACHEDDATATYPES__{dataTypeName.ToUpperInvariant()}__FRAMECOUNT environment variable.");
+        }
+        return frameCountConfig.Value;
     }
 
     /// <summary>
@@ -71,8 +75,20 @@ public static class CacheHelper
     {
         // Calculate based on actual wait times and frame count
         var frameCount = GetFrameCountForDataType(configuration, dataType);
-        var tileRenderWaitMs = configuration.GetValue<int>("Screenshot:TileRenderWaitMs", 5000);
-        var dynamicContentWaitMs = configuration.GetValue<int>("Screenshot:DynamicContentWaitMs", 2000);
+        
+        var tileRenderWaitMsConfig = configuration.GetValue<int?>("Screenshot:TileRenderWaitMs");
+        if (!tileRenderWaitMsConfig.HasValue)
+        {
+            throw new InvalidOperationException("Screenshot:TileRenderWaitMs configuration is required. Set it in appsettings.json or via SCREENSHOT__TILERENDERWAITMS environment variable.");
+        }
+        var tileRenderWaitMs = tileRenderWaitMsConfig.Value;
+        
+        var dynamicContentWaitMsConfig = configuration.GetValue<int?>("Screenshot:DynamicContentWaitMs");
+        if (!dynamicContentWaitMsConfig.HasValue)
+        {
+            throw new InvalidOperationException("Screenshot:DynamicContentWaitMs configuration is required. Set it in appsettings.json or via SCREENSHOT__DYNAMICCONTENTWAITMS environment variable.");
+        }
+        var dynamicContentWaitMs = dynamicContentWaitMsConfig.Value;
         
         // Rough calculation:
         // - Initial page load and navigation: ~10-15 seconds
diff --git a/Utilities/FilePathHelper.cs b/Utilities/FilePathHelper.cs
index c43813f..c781510 100644
--- a/Utilities/FilePathHelper.cs
+++ b/Utilities/FilePathHelper.cs
@@ -5,12 +5,12 @@ namespace BomLocalService.Utilities;
 public static class FilePathHelper
 {
     /// <summary>
-    /// Gets the cache directory path from configuration or returns default
+    /// Gets the cache directory path from configuration (default from appsettings.json, can be overridden via CACHEDIRECTORY environment variable)
     /// </summary>
     public static string GetCacheDirectory(IConfiguration configuration)
     {
-        return configuration.GetValue<string>("CacheDirectory") 
-            ?? Path.Combine(AppContext.BaseDirectory, "cache");
+        return configuration.GetValue<string>("CacheDirectory")
+            ?? throw new InvalidOperationException("CacheDirectory configuration is required. Set it in appsettings.json or via CACHEDIRECTORY environment variable.");
     }
 
     /// <summary>
diff --git a/appsettings.json b/appsettings.json
index debaea5..fa748d0 100644
--- a/appsettings.json
+++ b/appsettings.json
@@ -18,7 +18,6 @@
   "CacheManagement": {
     "CheckIntervalMinutes": 5,
     "InitialDelaySeconds": 10,
-    "UpdateStaggerSeconds": 2,
     "LocationStaggerSeconds": 1
   },
   "CacheCleanup": {
diff --git a/docker-compose.yml b/docker-compose.yml
index a3355d2..9289ef6 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -32,7 +32,6 @@ services:
       - CACHEEXPIRATIONMINUTES=${CACHEEXPIRATIONMINUTES:-12.5}
       - CACHEMANAGEMENT__CHECKINTERVALMINUTES=${CACHEMANAGEMENT__CHECKINTERVALMINUTES:-5}
       - CACHEMANAGEMENT__INITIALDELAYSECONDS=${CACHEMANAGEMENT__INITIALDELAYSECONDS:-10}
-      - CACHEMANAGEMENT__UPDATESTAGGERSECONDS=${CACHEMANAGEMENT__UPDATESTAGGERSECONDS:-2}
       - CACHEMANAGEMENT__LOCATIONSTAGGERSECONDS=${CACHEMANAGEMENT__LOCATIONSTAGGERSECONDS:-1}
       - CACHECLEANUP__INTERVALHOURS=${CACHECLEANUP__INTERVALHOURS:-1}
       - SCREENSHOT__DYNAMICCONTENTWAITMS=${SCREENSHOT__DYNAMICCONTENTWAITMS:-2000}