Can you use Vercel for backend? What works and when to use something else

Vercel is capable of handling backend functions, particularly lightweight tasks such as serverless functions and APIs that are closely integrated with the frontend, using frameworks like Next.js. However, its backend capabilities are limited, particularly when it comes to long-lived services, background jobs, persistent connections, and custom runtimes, as it lacks support for features like stateful services, native WebSocket connections, and persistent storage. For more complex backend requirements, platforms like Northflank offer greater flexibility and control, providing features such as always-on containers, persistent storage, built-in database support, and full-stack preview environments. Vercel's architecture is optimized for frontend-first development and short-lived, stateless backend tasks, which can be restrictive for applications needing more robust backend infrastructure.