Build a full-stack web app with AI by defining the contracts between interface, server, data, and operations before generating each layer. Start with one user journey and implement it end to end. A complete vertical slice reveals integration errors earlier than separate piles of frontend and backend code.
Write the domain entities, API inputs and outputs, authorization rules, page states, error model, and acceptance criteria. Choose the stack and pin the project’s commands and conventions. Ask the agent for a dependency-aware plan. Build the data model and server contract with fixtures, connect a plain interface, then test the journey across loading, empty, success, invalid, forbidden, and failure states. Keep environment variables documented without secrets. Separate optional services behind clear adapters and add observability where requests cross boundaries.
Use parallel agents only for work with frozen interfaces, such as independent components or tests. Keep shared schemas and contracts under one owner. Require lint, type, test, and build evidence, plus review of authentication, data migration, and deployment risk.
Your first milestone should be a deployable, reversible slice that a user can complete, not a collection of generated screens. Once that slice is understandable and verified, extend the same contracts feature by feature. This keeps AI speed from turning into integration debt.
