Java Backend Skills

Small, independent skills for clean, idiomatic Java and Spring backend development.

Each skill starts with a familiar engineering concept and directs a decision: what to inspect, how to reason, and what would make the result convincing. The model brings its language and framework knowledge. Your project supplies the versions, conventions, and constraints.

One SKILL.md per skill. No reference libraries, setup ceremony, mandatory process, or dependencies between skills.

Install

Versioned release: v1.0.0. Install selected skills, or the entire pack, into your current project:

npx skills@1.5.25 add "Dankosik/java-backend-skills#v1.0.0" --agent codex --skill '*' --copy

Use --skill java-implement for one skill, or --agent claude-code for Claude standalone placement. Node.js >=22.20.0 is required by this installer, not by the skill instructions.

For native Claude Code and Codex installation, add the Dankosik marketplace, then install java-backend-skills@dankosik-skills. The author catalog is available independently of review for either provider's public directory.

All installation methods, updates and rollback · Versioning · Changelog

Choose the decision

Skill	Leading concept	Use it for
java-implement	Execution	Turn clear requirements or a finished technical design into working code
java-idiomatic	Contracts	Clear Java implementations and behavior-preserving cleanup
java-design	Cohesion	Responsibilities, domain models, and useful abstractions
java-concurrency	Lifetime	Shared state, executors, virtual threads, cancellation, and bounds
java-debugging	Causality	Bugs, startup failures, hangs, and flaky behavior
java-performance	Evidence	Measured latency, throughput, CPU, memory, and startup improvements
java-build	Resolution	Maven, Gradle, toolchains, processors, and dependencies
spring-boot	Composition	Bean wiring, configuration, auto-configuration, and startup
spring-web	Translation	MVC/WebFlux endpoints, validation, serialization, and HTTP contracts
spring-data	Atomicity	Queries, persistence, transactions, migrations, and data races
spring-security	Authorization	Trusted identity, resource access, tenancy, and browser security
spring-integrations	Delivery semantics	External calls, retries, messages, jobs, and caches
spring-observability	Operability	Metrics, traces, logs, probes, and shutdown
java-unit-testing	Behavior	JUnit Jupiter, Mockito, AssertJ, and deterministic unit tests
spring-testing	Mechanism	Spring slices, application tests, Testcontainers, and real infrastructure

Use java-implement when the task is clear and the work is to implement it. Use a specialist when its particular decision needs attention. Each preserves supplied requirements and settled technical choices; none requires a design phase. Debugging identifies an uncertain cause; performance work measures a resource claim. Unit tests isolate ordinary behavior; Spring tests retain the framework or infrastructure mechanism being tested.

Use

Ask naturally, or select a skill through your agent's explicit skill invocation:

• “Use java-idiomatic to simplify this service while preserving its public behavior.”
• “Use java-implement to implement this specification without changing its technical design.”
• “Use spring-data to fix the duplicate reservation race.”
• “Use java-unit-testing to cover the discount rules with JUnit and Mockito.”
• “Use spring-testing to test this endpoint's validation and access control.”

These skills adapt to the repository's Java release and Spring generation. They do not prescribe an upgrade, architecture, or reactive rewrite. The pack focuses on application-level Java/Spring backend work; provider-specific deployment and specialist infrastructure remain project concerns.

Contribute

Keep each skill independent and decision-focused. Prefer an established concept over a new glossary, a discriminating trigger over a capability catalog, and an observable outcome over a long checklist. Improve wording against a realistic task that exposed a weakness. Keep version lookups and API tutorials out of the skill.

The pack uses the Agent Skills format. Structural validity and a few useful examples do not establish a universal improvement across models.

Acknowledgements

Inspired by the focused technical judgments in Dankosik/go-service-template-rest and the leading concepts and composability of mattpocock/skills. The Java/Spring instructions are independently written.

MIT license.