Certificate

# Java certificate - outline

## Part 1 - exam (75 min)

Topics:
- Language: records, sealed types, pattern matching, text blocks
- Collections + Streams
- Concurrency: virtual threads, structured concurrency, CompletableFuture
- JDBC + JPA, transaction semantics
- Spring Boot basics
- Testing with JUnit 5 + Mockito + Testcontainers

Passing mark: 70 percent.

## Part 2 - capstone (take-home, ~10 hours)

Ship a small Spring Boot REST API:

- Java 21 LTS
- Spring Boot 3.x with minimal starters
- 5 endpoints minimum (CRUD + auth via JWT)
- Validation with jakarta.validation
- Persistence with Spring Data JPA + Postgres
- Testcontainers integration tests (no H2)
- Observability: Micrometer + OpenTelemetry
- Build: Gradle Kotlin DSL or Maven
- Container: multi-stage Docker image, non-root user
- CI: GitHub Actions with unit + integration tests + image build

Submit a Git repo + a container image.

## Grading

- Correctness (35 percent)
- Modern Java usage (records, sealed, virtual threads) (20 percent)
- Tests (20 percent)
- Operability (15 percent)
- Documentation (10 percent)

## Tips

- Use records for DTOs; sealed for domain types
- Enable virtual threads in Spring 6.1+
- Skip H2; use Testcontainers
- Treat the image as production - non-root, healthcheck, pinned base

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