Lead Java Backend Engineer

Infoplus Technologies UK Limited; Województwo małopolskie; Hybrid; PLN 180,000 - 300,000; Full time

Job summary

Infoplus Technologies UK Limited is seeking a senior software engineer in Krakow to lead a skilled team in a hybrid work model (min 3 days on-site). You will guide design choices and engineering standards while mentoring peers.

The role focuses on Java 8–21 and Kotlin Spring Boot microservices, Kafka-based event flows, and cloud-native deployments on GCP, with emphasis on performance, reliability, and secure SDLC practices.

Qualifications

• 8+ years of hands-on Java software engineering in large-scale or complex environments, including experience in a technical lead role.
• Experience delivering scalable microservices with Spring Boot and designing REST APIs; Kotlin experience is a plus.
• Strong knowledge of Java versions (8/11/17/21) and migrating apps across versions.
• Proficiency with Kafka/Kafka Streams and relational data stores (PostgreSQL).

Responsibilities

• Provide hands-on technical leadership to engineers, guiding design, implementation, and engineering standards.
• Design, build, and evolve Java (8-21) and Kotlin Spring Boot microservices and REST APIs across the order/trade lifecycle.
• Build event-driven flows using Kafka and Kafka Streams for real-time processing.
• Deliver containerized services with Docker and Kubernetes on GCP; manage data on PostgreSQL.
• Apply CI/CD, secure SDLC, and automated testing with JUnit and Mockito.
• Own L3 production support including performance profiling and root-cause analysis.
• Use GenAI-assisted development to improve productivity and code quality.
• Collaborate with Product Owners, Architects, and engineers; lead code reviews and testing strategies.
• Drive modernization toward modular, cloud-native, event-driven architectures on GCP.

Skills

Java

Spring Boot

Kafka

Kubernetes

Docker

PostgreSQL

CI/CD

Unit testing

GenAI tools

Technical leadership

Education

Bachelor's or Master's degree in CS/Engineering

Tools

Claude Code

Job description

Location:Krakow, Poland (Min 3 days hybrid mandatory)

Key responsibilities will be :

• 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.

Your expertise

Software engineering & technical skills

• 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.

Qualifications

• 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.

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.