A Backend-for-Frontend (BFF) pattern is a specialized server-side API that serves as an intermediary between the frontend and various downstream APIs, aggregating and transforming data as needed before delivering it to the client. BFFs are not just simple proxies; they're purpose-built for one client/user experience, with each being smaller and less complex than an API gateway. They can relieve some of the burden on both your client and backend services, making their codebase more focused and maintainable. Building production-ready BFFs requires understanding the importance of caching, authentication, logging, normalizing errors, integration testing, embracing duplication, and maintaining documentation. Adopting a BFF framework like WunderGraph can simplify the process and provide a better developer experience.