Developer Builds Choose-Your-Own-Adventure REST API to Learn NestJS From Scratch

A developer is documenting their backend learning journey by building 'Grimoire API', a REST API powering a choose-your-own-adventure game with XP and badge mechanics. The project, shared on DEV Community, is structured so each milestone maps to a specific NestJS concept rather than following generic tutorial patterns. The first milestone covers creating a single working endpoint, GET /pages/:id, that returns a story page as JSON. The post breaks down four core NestJS building blocks — controllers, services, modules, and dependency injection — explaining how they interact to handle HTTP requests cleanly. The author highlights how dependency injection simplifies testing by allowing fake service instances to be passed to controllers without modifying any production code.