Serverless Functions vs. Form-as-a-Service: Choosing a React Form Backend

React handles the UI side of forms easily, but developers still need a backend solution to validate, process, and store submissions. Two common approaches exist: writing a custom serverless function on platforms like Vercel or Netlify, or using a hosted form-as-a-service such as onsubmit.dev. Serverless functions offer full control over the request lifecycle, including validation, authentication, and data routing, but require teams to manage spam protection, rate limiting, monitoring, and other infrastructure concerns. Form-as-a-service platforms offload that generic infrastructure to a hosted provider, making them well-suited for contact forms, feedback forms, and waitlists where a custom API adds little core value. The custom function approach remains the stronger choice when form submission is tightly coupled to application logic, such as checkouts, account workflows, or operations requiring database transactions and private service calls.