Java Integration Testing (Reproducible, CI-Friendly)

Why this skill exists

Integration tests catch failures that unit tests cannot: incorrect wiring, serialization/deserialization, transaction boundaries, connection pool settings, schema drift, message ack/retry behavior, and “works on my machine” config issues.

The goal is NOT to replace unit tests. The goal is to:

• Reproduce IO/DB/queue bugs deterministically
• Validate runtime wiring (config, DI, modules, migrations)
• Provide confidence that changes remain deployable

Scope

In scope