A grown Spring project on an outdated Java and framework version is broken into checkable slices and moved step by step to a defined target level.
Case study in full
Synthetic example — illustrative magnitudes, not a measurement.
Stack profile: java-spring-boot-4-hexagonal · Data origin: Synthetic example, not a reference run. · Measurement period: —J
A grown Spring project runs on an outdated Java and framework version. Dependencies have accumulated over years, part of the test suite is red or skipped, and migrating to a defined target level was repeatedly postponed because it did not break down into small, checkable steps.
Out of scope — not automated: Not automated: which target level is pursued remains a project decision made in advance. Review of every single slice, approval of critical dependency changes, and the final merge decision remain with a human throughout.
Prerequisites
Repository with an existing build configuration (Gradle/Maven) and a runnable test suite as the starting point.
A stack profile naming the target version and architecture conventions.
Guardrails that record the project's binding conventions.
Approval of the ticket backlog by a project member before the first run.
Workflow
A ticket in the connected tracker describes the target level per module.
The plan breaks the migration into ordered, individually checkable slices.
Each slice changes one bounded portion: a dependency, an API adjustment, or a test fix.
Validation per slice: compilation, affected tests, static analysis.
The result goes out as a pull request to the repository — review and merge remain with a human.
Result artifacts
Changed files and dependencies per slice, traceable in the commit history.
Test results and gate status documented per slice.
One pull request per slice or bundled, referencing the ticket.
Points left open are recorded as separate backlog tickets, not silently dropped.
Key figures
Scope
Stories/tickets
1
Slices
34
Files/modules
118
Throughput
Validated slices
31
Retries
9
Human approvals
6
Quality
Checks run
Compile, Unit Tests, Static Analysis
Gates passed
5
Gates failed
1
Remaining debt
Two older test classes do not yet cover the new code path; deferred as a ticket rather than silently removed.
Resources — no pricing
Prompt tokens
500000
Completion tokens
200000
Cache tokens
750000
Model calls
200
Sandbox runtime
90 minutes
Model/stack context
Java 17 → Java 25, Spring Boot 3 → Spring Boot 4 (target profile java-spring-boot-4-hexagonal).
Every example on this page was created for illustration. It is not a promise about the duration, quality or cost of a future run of your own — your own figures appear in the cockpit after logging in, within your own tenant context.
