Senior Java Developer (AppSec.Hub)

Senior Java Developer at Swordfish Security. 6+ years experience. Full-time, remote/hybrid/office. Core microservices with Java 17, Micronaut, event-driven architecture.

Design and develop core microservices in Java 17 / Micronaut (no Spring). Work with event-driven exchange: all inter-service communication via message broker, async-first, database-per-service, eventual consistency. Solve high-load processing tasks: multithreading, non-blocking I/O, GC and JIT optimization. Work with data: PostgreSQL (via MyBatis), analytics on ClickHouse, cache and read-models on Redis. Cover observability (metrics/logs/tracing) – currently a growth area in services. Actively use AI-assisted development (Claude) – part of daily process.\nCore: Java 17 + Micronaut (no Spring), built-in Netty. Lightweight framework and targeted libraries, direct control over threads, I/O, and memory. Exchange: asynchronous, via broker (LavinMQ / AMQP) – async-first, database-per-service, eventual consistency. Data: PostgreSQL (MyBatis), ClickHouse, Redis. Contracts: Protocol Buffers (messages) + OpenAPI 3.1 (REST). Operations: Docker / Kubernetes.

Java 17 at platform level; Micronaut 4.x (no imposed dependency on Spring). I/O: io / nio / nio2; understanding of built-in HTTP server (Netty). Stream API. Multithreading and concurrency, understanding JMM. Understanding JIT and GC, ability to diagnose and optimize. GraalVM / native-image. Confident work with relational databases and understanding how they work internally: transactions and isolation, indexes, planner, connection pool. Main PostgreSQL (MySQL / other relational – no matter, the model is important). MyBatis (over JDBC) and migrations (Liquibase). ClickHouse (analytics / eventstore). Redis (cache, CQRS read-models). AMQP: LavinMQ / RabbitMQ – producers/consumers, exchange types (direct/topic/fanout). Reliability patterns: idempotency, at-least-once, retries, eventual consistency, backpressure. Protocol Buffers (proto3) as message serialization (not gRPC-RPC). HTTP/1.1 and HTTP/2. Docker, Kubernetes. Observability: metrics, logs, distributed tracing. Vibecoding: prompt engineering for Claude, using skills and subagents. Mandatory selection condition: bring a live, non-trivial Java project – we will analyze it together.