React + .NET: Lessons from Real-World Integration

Integrating React with .NET APIs may seem straightforward: just fetch some REST endpoints and you're good to go. But in real-world production scenarios, achieving robust, secure, and scalable communication takes much more than having your endpoints online.

Across several production projects, I’ve learned what truly works when React and .NET need to collaborate — especially when scalability, reactivity, and maintainability are on the line.

Common challenges I faced (and how I solved them):

Mismatched expectations between client and server

The frontend expects clean JSON responses, friendly messages, and consistent status codes. Out of the box, .NET can return cryptic codes or even HTML error pages.
Solution: I standardized all API responses using a custom error middleware and a generic Result<T> wrapper.

Poor async handling

In a React dashboard consuming multiple endpoints in parallel, a single failed request would crash the entire component.
Solution: We used Promise.allSettled to handle each request individually, with section-based loaders and cached fallbacks.

Global state vs. caching

Using Redux solely for REST responses made the app sluggish and hard to maintain.
Today, I rely on React Query (TanStack) with built-in caching, auto refetching, retries, and resource-specific invalidation — much more efficient.

JWT authentication and refresh issues

The backend issued short-lived tokens, but the frontend failed to refresh them properly, causing silent failures.
We implemented an Axios interceptor for automatic token refresh and a graceful fallback to logout if needed.

API versioning confusion

Multiple API versions coexisting led to frontend confusion and bugs.
We introduced versioned routes (/api/v1/...) and created a typed apiClient.ts for each version, validating schemas with Zod.

Silent error handling issues

The frontend received 400/500 statuses without clear user feedback.
We built a global error display system that parsed and categorized API messages into technical and user-facing formats.

Divergent environment configurations

The API ran locally with HTTPS, but staging used HTTP — causing CORS and cookie issues.
We standardized URLs via .env files and configured Axios with withCredentials to ensure consistent authentication.

Best practices I follow today:

Standardize API response structure (data, errors, status)
Validate inputs using Zod on the frontend and FluentValidation on the backend
Use React Query with cache strategies tailored by resource
Intercept errors and JWT logic using Axios interceptors
Document endpoints using Swagger with real examples
Centralize environment configuration to avoid inconsistencies
Abstract API logic into reusable, strongly-typed service layers (apiClient)

Conclusion

Integrating React and .NET can be a powerful combination — but only if built on clear contracts, thoughtful error handling, and a focus on user experience.

These two ecosystems work beautifully together in production, as long as both sides speak the same language: clean contracts, predictable behavior, and robust security.

Following these practices allows teams to scale, features to evolve, and the codebase to remain healthy — even under pressure.