1. Plan a coherent service and API contract
Start with the contract: make inputs, outputs and failure behavior explicit before adding infrastructure. This keeps the feature easy to reason about and gives tests a stable boundary.
2. Secure, test and observe the system
Apply the pattern through a small vertical slice. Keep framework wiring at the edge and business decisions in focused functions or services that can be tested without starting the whole application.
# Definition of done
# [ ] migrations and seed strategy
# [ ] authentication and authorization
# [ ] unit + integration + API tests
# [ ] logs, metrics, health checks
# [ ] non-root container and CI pipeline
# [ ] deployed URL and concise README3. Containerize, deploy and document it
Treat failure paths as part of the design. Add bounded resource usage, meaningful errors and a verification step so the behavior remains dependable under real production conditions.
4. Hands-on Exercise
Build the feature
Build and deploy a portfolio-grade service such as issue tracking, bookings or inventory. Record architectural decisions and prove every definition-of-done item.
Definition of done
- The happy path works through the real HTTP boundary.
- At least one failure path is handled and tested.
- Configuration and secrets stay outside source code.
- The README explains how to run and verify the result.
5. Knowledge Check
What makes this project production-ready rather than merely feature-complete?
Show answer
It includes operational qualities - security, tests, failure handling, observability, repeatable deployment and documentation - not just endpoints.