Lead Java Backend Engineer

Project overview

Mandatory skill

Java 8, 11, 17, and 21, including migrating applications across Java versions, microservices, Spring Boot, and REST APIs; Kotlin. Containerized services with Docker and Kubernetes on GCP(Google Cloud Platform) through CI/CD

Responsibilities

Your expertise

Software engineering & technical skills

Collaboration & delivery

• Provide hands‑on technical leadership to the crew, guiding engineers on design, implementation, and engineering standards, and mentoring team members to grow their skills.
• Design, build, and enhance Java (8–21) and Kotlin Spring Boot microservices and REST APIs across the order and trade lifecycle, including order capture, validation, routing, execution, allocation, and booking.
• Build event‑driven flows using Kafka and Kafka Streams to deliver reliable, real‑time order and trade processing.
• Deliver containerized services with Docker and Kubernetes on GCP, and manage data on PostgreSQL.
• Apply engineering best practices, including clean code, CI/CD, secure SDLC, and automated testing with JUnit and Mockito.
• Own L3 production support, including performance profiling, incident resolution, and root cause analysis, keeping low‑latency, high‑throughput trading services resilient and stable.
• Use GenAI‑assisted development, including Claude Code, to improve engineering productivity and code quality across the team.
• Collaborate closely with Product Owners, Architects, and engineers, and lead code reviews, testing strategies, and troubleshooting of complex technical issues.
• Drive modernization efforts by evolving legacy systems toward modular, cloud‑native, and event‑driven architectures on GCP.
• Strong hands‑on experience in Java 8, 11, 17, and 21, including migrating applications across Java versions, building scalable microservices with Spring Boot, and designing REST APIs; experience with Kotlin.
• Experience with event‑driven architectures using Kafka and Kafka Streams, and with relational data stores such as PostgreSQL.
• Experience delivering containerized services with Docker and Kubernetes on GCP through CI/CD pipelines with automated testing, applying performance optimization, reliability, and secure development practices to low‑latency, high‑throughput services.
• Proven experience in L3 production support, including performance profiling, incident resolution, and root cause analysis of complex production issues.
• Hands‑on experience with GenAI‑assisted development, using tools such as Claude Code to improve productivity and code quality.
• Experience providing technical leadership and guidance to engineers while contributing hands‑on to development and problem solving of complex technical challenges.
• Experience working in Agile delivery models.
• Strong collaboration skills across engineering, product, and architecture teams.
• Ability to communicate technical concepts effectively with both technical and non‑technical stakeholders.

Requirements

• Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field (or equivalent experience).
• 8+ years of hands‑on Java software engineering experience within large‑scale or complex environments, including experience in a technical lead role.
• Claude Certified Architect – Foundations certification.

Nice to have

• Exposure to order management, trade execution, or trading platforms in financial services or wealth management.
• Experience contributing to engineering standards, best practices, or shared components.

Project details

• Start: flexible
• Remote: hybrid
• Location: Kraków, Krakow, PL
• Rate: 138-163 EUR/h