Design reproducible build, image, and deployment pipelines for Kotlin plus Spring applications, including CI verification, layered containers, rollout safety, and deployment-time migration coordination. Use when creating or improving Dockerfiles, CI workflows, image hardening, Kubernetes manifests, release gates, or deployment strategies for Spring Boot services, especially where build reproducibility and operational safety matter.
Design and diagnose Spring configuration, profiles, and `@ConfigurationProperties` binding for Kotlin applications. Use when property binding fails, environment-specific overrides behave unexpectedly, profile layering is confusing, secrets or defaults are modeled unsafely, or Kotlin nullability and constructor binding semantics make configuration errors hard to detect.
Diagnose and resolve Gradle and Spring classpath conflicts, version drift, and binary incompatibilities in Kotlin applications. Use when `NoSuchMethodError`, `ClassNotFoundException`, linkage errors, duplicate logging bindings, Jackson or Hibernate mismatches, or BOM-versus-explicit-version conflicts appear, and the fix must respect the repository's real version authorities.
Decompose business scope into bounded contexts, module or service boundaries, workflows, and API contracts before implementation begins. Use when shaping a new feature, service, or major redesign; when requirements are underspecified; when consistency, idempotency, and integration boundaries must be made explicit; or when ADR-quality tradeoff reasoning is needed for Kotlin plus Spring systems.
Design and implement consistent API validation and error-handling behavior for Kotlin plus Spring services. Use when defining error payloads, mapping framework and domain exceptions, standardizing HTTP status codes, adding `@ControllerAdvice`, preventing internal-detail leakage, or ensuring clients can rely on stable machine-readable error semantics across endpoints.
Generate, debug, and repair Kotlin + Spring Gradle builds with minimal, compatible changes. Use when `build.gradle.kts` or `settings.gradle.kts` is failing, plugins or toolchains are incompatible, dependency management is drifting from the Spring Boot BOM, test or runtime classpaths are broken, or a Kotlin DSL patch must be safe and incremental.
Design resilient HTTP, messaging, and scheduled integrations for Kotlin plus Spring services with explicit timeout budgets, retries, idempotency, circuit breakers, DLQ behavior, and failure observability. Use when integrating with unstable external systems, designing retry logic, handling duplicate delivery, preventing thundering herds, or making message-driven and scheduled workflows safe in production.
Diagnose and design JSON serialization and deserialization behavior for Kotlin plus Jackson in Spring applications. Use when DTOs fail to deserialize, default parameters or nullability behave unexpectedly, date-time or enum formats drift, polymorphic payloads are involved, PATCH semantics must distinguish null from absent, or ObjectMapper changes risk breaking existing API or message contracts.