Real project experience: You’ve built something real (a side project, open-source contribution, or hackathon win) touching several of: a relational database (schema design, queries, indexes), authentication (JWT, sessions, OAuth, implemented, not just read about), a cache layer (Redis or similar), an API with real error handling (400s, 401s, 500s, not just 200s), a message queue or background job (Kafka, SQS, Celery, or a simple cron), and deploying something beyond localhost (Docker, a cloud VM, or a serverless function).