diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c7a24dd..80dbb40 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -48,6 +48,11 @@ jobs:
       - name: Lint
         run: npm run lint
 
+        # TODO: duplicate build step; consider removing from here and only keeping in build-and-push
+        # once we figure a better way to prevent build errors from reaching build-and-push job.
+      - name: Build
+        run: npm run build
+
       - name: Test
         run: npm run test
 
diff --git a/src/api/middleware/errorHandler.ts b/src/api/middleware/errorHandler.ts
index 8912991..545c833 100644
--- a/src/api/middleware/errorHandler.ts
+++ b/src/api/middleware/errorHandler.ts
@@ -31,26 +31,37 @@ export function errorHandler(
 ): void {
     const errorId = generateErrorId();
 
+    // Extract error properties with safe type handling.
+    // We accept Error | unknown and need to safely access properties that may exist
+    // on Error objects (message), HTTP error objects (statusCode, status), or custom
+    // error objects (code). Type casting to any is necessary to access these
+    // arbitrary properties while maintaining runtime safety through optional chaining.
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const errorObj = err as any; // Allow accessing arbitrary properties
+    const errorMessage = errorObj?.message ?? String(err);
+    const errorType = errorObj?.constructor?.name ?? 'Unknown';
+    const statusCode = errorObj?.statusCode ?? errorObj?.status ?? 500;
+    const errorCode = errorObj?.code;
+
     // Log the full error internally with correlation ID (safe location)
     log.error({
         message: 'API error',
         data: {
             errorId,
-            type: err?.constructor?.name || 'Unknown',
-            message: err?.message || String(err)
+            type: errorType,
+            message: errorMessage
         }
     });
 
     // Return safe error response to client with error ID for tracing
-    const statusCode = err?.statusCode || err?.status || 500;
     const errorResponse: ErrorResponse = {
         error: 'An error occurred processing your request',
         errorId
     };
 
     // Add code if it's a validation error or known error type
-    if (err?.code) {
-        errorResponse.code = err.code;
+    if (errorCode) {
+        errorResponse.code = errorCode;
     }
 
     res.status(statusCode).json(errorResponse);
diff --git a/src/api/middleware/logging.ts b/src/api/middleware/logging.ts
index a453fb8..f18bbb5 100644
--- a/src/api/middleware/logging.ts
+++ b/src/api/middleware/logging.ts
@@ -11,9 +11,18 @@ export function requestLogging(req: Request, res: Response, next: NextFunction):
     const startTime = Date.now();
     const clientIp = getClientIP(req);
 
-    // Override res.end to capture response
-    const originalEnd = res.end;
-    res.end = function (chunk?: Buffer | string, encoding?: string): Response {
+    // Override res.end to capture response timings and metadata.
+    // Express Response.end has multiple overloaded signatures:
+    //   end(): Response
+    //   end(callback: Function): Response
+    //   end(data: Buffer | string): Response
+    //   end(data: Buffer | string, callback: Function): Response
+    //   end(data: Buffer | string, encoding: string, callback: Function): Response
+    // We accept variadic args to match all overloads while preserving the original
+    // function's ability to handle any combination of parameters.
+    const originalEnd = res.end.bind(res);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    res.end = function (...args: any[]): Response {
         const duration = Date.now() - startTime;
 
         log.debug({
@@ -27,8 +36,8 @@ export function requestLogging(req: Request, res: Response, next: NextFunction):
             }
         });
 
-        return originalEnd.call(this, chunk, encoding);
-    };
+        return originalEnd(...args);
+    } as typeof res.end;
 
     next();
 }