Use when you need to add or review Mongock MongoDB data migrations in a Spring Boot application — including Maven coordinates, Spring Data MongoDB drivers, migration scan packages, @ChangeUnit classes, lock/transaction settings, and optional policy-approved MongoDB integration verification. This should trigger for requests such as Add Mongock migrations in Spring Boot; Review Spring MongoDB data migrations; Configure Mongock change units for Spring Data MongoDB; Create Mongock change units for S
SkillScore82Maintained
Automatic
◆Coding pack
Last verified 8/20/2026
What it changes
Passed 15 of 18 test cases with the skill, and 12 of 18 without it.
Without skill68%
With skill82%
Checks it passed that the model alone missed
Specified running a project compilation command prior to writing code.
Defined explicit numeric order attributes on the `@ChangeUnit` annotations.
Configured package discovery using the property `mongock.migration-scan-package`.
and 3 more in the full report
5 fixed13 passed either way2 still failing2 broke
Pass-rate lift
+14 pp
Tokens
+15%
Agent turns
0%
Response time
-28%
Model gemini-3.6-flashMeasured 8/20/2026v118 of 22 cases passed with skill · 18 comparable
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 5 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 5
Prompt
We need to set our Spring Boot application properties so that database migration classes in package `com.example.app.migrations` are detected automatically at startup. Which YAML property key should we set?
What was checked, without and with the skill
Checked
Without skill
With skill
Configured package discovery using the property `mongock.migration-scan-package`.
Missed
Passed
case-09 · gemini-3.6-flash · 8/20/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md59 lines4 files
Spring - MongoDB migrations (Mongock)
Apply Mongock migration guidelines for Spring Boot and Spring Data MongoDB.
What is covered in this Skill?
Mongock BOM, Spring Boot runner, and Spring Data MongoDB driver coordinates
mongock.migration-scan-package configuration and startup execution
Code-first @ChangeUnit migrations with @Execution and rollback hooks
Locking, idempotency, transaction limits, and forward-only rollout discipline
Optional MongoDB-backed integration tests using only project-approved, pinned, or already-available container images when the user permits external runtime dependencies
Coordination with @315-frameworks-spring-mongodb
Scope: Apply recommendations based on the reference rules and good/bad examples.
Constraints
Compile before Mongock or MongoDB migration changes; verify after changes.
MANDATORY: Run ./mvnw compile or mvn compile before applying any change
SAFETY: If compilation fails, stop immediately
VERIFY: Run ./mvnw clean verify or mvn clean verify after applying improvements
BEFORE APPLYING: Read the reference for detailed rules and good/bad patterns
EDGE CASE: If the project Spring Data MongoDB version is not compatible with the selected Mongock driver, stop and ask whether to pin/upgrade Mongock or use a lower driver generation
EXTERNAL RUNTIME GATE: Do not pull or execute Docker images for MongoDB verification unless the user explicitly approves and the image is pinned, policy-approved, or already present in the project configuration
When to use this skill
Add Mongock migrations in Spring Boot
Review Spring MongoDB data migrations
Configure Mongock change units for Spring Data MongoDB
Create Mongock change units for Spring Boot MongoDB
Review Mongock migration ordering in a Spring service
Workflow
Read references and inspect MongoDB setup
Read references/316-frameworks-spring-mongodb-migrations-mongock.md, references/316-frameworks-spring-mongodb-migrations-mongock-antipatterns.md, and references/316-frameworks-spring-mongodb-migrations-mongock-parallel-change.md, then inspect pom.xml, Spring Boot version, dependency management, MongoDB configuration, existing full-context tests, and existing @315-frameworks-spring-mongodb persistence patterns.
Use when you need to implement acceptance tests from maintainer-authored or maintainer-sanitized Gherkin scenario facts for Spring Boot applications — including selecting scenarios tagged @acceptance, implementing happy path tests with TestRestTemplate, @SpringBootTest, Testcontainers with @ServiceConnection for DB/Kafka, and WireMock for external REST stubs. Never ingest raw .feature files. This should trigger for requests such as Review Java code for Spring Boot acceptance tests; Apply best pr