java-architect skill

by Jeffallan·Jeffallan/claude-skills·12k stars·MIT

Use when building, configuring, or debugging enterprise Java applications with Spring Boot 3.x, microservices, or reactive programming. Invoke to implement WebFlux endpoints, optimize JPA queries and database performance, configure Spring Security with OAuth2/JWT, or resolve authentication issues and async processing challenges in cloud-native Spring applications.

A100/100content scan

Is the java-architect skill safe?

Clean: nothing in its files matched our rules. We read 6 files in the folder on 2026-09-28.

No findings.

Install the java-architect skill

A skill is a folder. Copy it into your agent's skills folder and the agent loads it when the task matches its description.

git clone --depth 1 https://github.com/Jeffallan/claude-skills.git /tmp/claude-skills
mkdir -p ~/.claude/skills
cp -r /tmp/claude-skills/skills/java-architect ~/.claude/skills/java-architect

available in every project

In the Claude apps, zip the folder and upload it from the Skills settings. The folder on GitHub

The instructions your agent would load

SKILL.md as published, without the frontmatter. Read it on GitHub

Java Architect

Enterprise Java specialist focused on Spring Boot 3.x, microservices architecture, and cloud-native development using Java 21 LTS.

Core Workflow

Architecture analysis - Review project structure, dependencies, Spring config
Domain design - Create models following DDD and Clean Architecture; verify domain boundaries before proceeding. If boundaries are unclear, resolve ambiguities before moving to implementation.
Implementation - Build services with Spring Boot best practices
Data layer - Optimize JPA queries, implement repositories; run ./mvnw verify -pl to confirm query correctness. If integration tests fail: review Hibernate SQL logs, fix queries or mappings, re-run before proceeding.
Security & config - Apply Spring Security, externalize configuration, add observability; run ./mvnw verify after security changes to confirm filter chain and JWT wiring. If tests fail: check SecurityFilterChain bean order and token validation config, then re-run.
Quality assurance - Run ./mvnw verify (Maven) or ./gradlew check (Gradle) to confirm all tests pass and coverage reaches 85%+ before closing. If coverage is below threshold: identify untested branches via JaCoCo report (target/site/jacoco/index.html), add missing test cases, re-run.

Reference Guide

Load detailed guidance based on context:

Constraints

MUST DO

Use Java 21 LTS features (records, sealed classes, pattern matching)
Apply database migrations (Flyway/Liquibase)
Document APIs with OpenAPI/Swagger
Use proper exception handling hierarchy
Externalize all configuration (never hardcode values)

MUST NOT DO

Use deprecated Spring APIs
Skip input validation
Store sensitive data unencrypted
Use blocking code in reactive applications
Ignore transaction boundaries

Output Templates

When implementing Java features, provide:

Domain models (entities, DTOs, records)
Service layer (business logic, transactions)
Repository interfaces (Spring Data)
Controller/REST endpoints
Test classes with comprehensive coverage
Brief explanation of architectural decisions

Code Examples

Minimal WebFlux REST Endpoint

@RestController
@RequestMapping("/api/v1/orders")
@RequiredArgsConstructor
public class OrderController {

    private final OrderService orderService;

    @GetMapping("/{id}")
    public Mono<ResponseEntity<OrderDto>> getOrder(@PathVariable UUID id) {
        return orderService.findById(id)
                .map(ResponseEntity::ok)
                .defaultIfEmpty(ResponseEntity.notFound().build());
    }

    @PostMapping
    @ResponseStatus(HttpStatus.CREATED)
    public Mono<OrderDto> createOrder(@Valid @RequestBody CreateOrderRequest request) {
        return orderService.create(request);
    }
}

JPA Repository with Optimized Query

public interface OrderRepository extends JpaRepository<Order, UUID> {

    // Avoid N+1: fetch association in one query
    @Query("SELECT o FROM Order o JOIN FETCH o.items WHERE o.customerId = :customerId")
    List<Order> findByCustomerIdWithItems(@Param("customerId") UUID customerId);

    // Projection to limit fetched columns
    @Query("SELECT new com.example.dto.OrderSummary(o.id, o.status, o.total) FROM Order o WHERE o.status = :status")
    Page<OrderSummary> findSummariesByStatus(@Param("status") OrderStatus status, Pageable pageable);
}

Spring Security OAuth2 JWT Configuration

@Configuration
@EnableMethodSecurity
public class SecurityConfig {

    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
        return http
                .csrf(AbstractHttpConfigurer::disable)
                .sessionManagement(s -> s.sessionCreationPolicy(STATELESS))
                .authorizeHttpRequests(auth -> auth
                        .requestMatchers("/actuator/health").permitAll()
                        .anyRequest().authenticated())
                .oauth2ResourceServer(oauth2 -> oauth2.jwt(Customizer.withDefaults()))
                .build();
    }
}

Knowledge Reference

Spring Boot 3.x, Java 21, Spring WebFlux, Project Reactor, Spring Data JPA, Spring Security, OAuth2/JWT, Hibernate, R2DBC, Spring Cloud, Resilience4j, Micrometer, JUnit 5, TestContainers, Mockito, Maven/Gradle

Documentation

More skills from Jeffallan/claude-skills

Aangular-architectGenerates Angular 17+ standalone components, configures advanced routing with lazy loading and guards, implements NgRx state management, applies RxJS patterns, and optimizes bundle performance. Use when building Angular 17+ applications with standalone components or signals, setting up NgRx stores, establishing RxJS reactive patterns, performance tuning, or writing Angular tests for enterprise apps.
Aapi-designerUse when designing REST or GraphQL APIs, creating OpenAPI specifications, or planning API architecture. Invoke for resource modeling, versioning strategies, pagination patterns, error handling standards.
Aarchitecture-designerUse when designing new high-level system architecture, reviewing existing designs, or making architectural decisions. Invoke to create architecture diagrams, write Architecture Decision Records (ADRs), evaluate technology trade-offs, design component interactions, and plan for scalability. Use for system design, architecture review, microservices structuring, ADR authoring, scalability planning, and infrastructure pattern selection — distinct from code-level design patterns or database-only design tasks.
Aatlassian-mcpIntegrates with Atlassian products to manage project tracking and documentation via MCP protocol. Use when querying Jira issues with JQL filters, creating and updating tickets with custom fields, searching or editing Confluence pages with CQL, managing sprints and backlogs, setting up MCP server authentication, syncing documentation, or debugging Atlassian API integrations.
Achaos-engineerDesigns chaos experiments, creates failure injection frameworks, and facilitates game day exercises for distributed systems — producing runbooks, experiment manifests, rollback procedures, and post-mortem templates. Use when designing chaos experiments, implementing failure injection frameworks, or conducting game day exercises. Invoke for chaos experiments, resilience testing, blast radius control, game days, antifragile systems, fault injection, Chaos Monkey, Litmus Chaos.
Acli-developerUse when building CLI tools, implementing argument parsing, or adding interactive prompts. Invoke for parsing flags and subcommands, displaying progress bars and spinners, generating bash/zsh/fish completion scripts, CLI design, shell completions, and cross-platform terminal applications using commander, click, typer, or cobra.
Acloud-architectDesigns cloud architectures, creates migration plans, generates cost optimization recommendations, and produces disaster recovery strategies across AWS, Azure, and GCP. Use when designing cloud architectures, planning migrations, or optimizing multi-cloud deployments. Invoke for Well-Architected Framework, cost optimization, disaster recovery, landing zones, security architecture, serverless design.
Acode-documenterGenerates, formats, and validates technical documentation — including docstrings, OpenAPI/Swagger specs, JSDoc annotations, doc portals, and user guides. Use when adding docstrings to functions or classes, creating API documentation, building documentation sites, or writing tutorials and user guides. Invoke for OpenAPI/Swagger specs, JSDoc, doc portals, getting started guides.
Acode-reviewerAnalyzes code diffs and files to identify bugs, security vulnerabilities (SQL injection, XSS, insecure deserialization), code smells, N+1 queries, naming issues, and architectural concerns, then produces a structured review report with prioritized, actionable feedback. Use when reviewing pull requests, conducting code quality audits, identifying refactoring opportunities, or checking for security issues. Invoke for PR reviews, code quality checks, refactoring suggestions, review code, code quality. Complements specialized skills (security-reviewer, test-master) by providing broad-scope review across correctness, performance, maintainability, and test coverage in a single pass.
Acpp-proWrites, optimizes, and debugs C++ applications using modern C++20/23 features, template metaprogramming, and high-performance systems techniques. Use when building or refactoring C++ code requiring concepts, ranges, coroutines, SIMD optimization, or careful memory management — or when addressing performance bottlenecks, concurrency issues, and build system configuration with CMake.
Acsharp-developerUse when building C# applications with .NET 8+, ASP.NET Core APIs, or Blazor web apps. Builds REST APIs using minimal or controller-based routing, configures database access with Entity Framework Core, implements async patterns and cancellation, structures applications with CQRS via MediatR, and scaffolds Blazor components with state management. Invoke for C#, .NET, ASP.NET Core, Blazor, Entity Framework, EF Core, Minimal API, MAUI, SignalR.
Adatabase-optimizerOptimizes database queries and improves performance across PostgreSQL and MySQL systems. Use when investigating slow queries, analyzing execution plans, or optimizing database performance. Invoke for index design, query rewrites, configuration tuning, partitioning strategies, lock contention resolution.

All agent skills → · MCP servers