Senior Java Developer

ITRex Group; Polska; A distancia; PLN 180.000 - 250.000; Jornada completa

Ventajas ofrecidas por este puesto de trabajo

Remote flexibility

Competitive salary

English language training

Career progression

AI enhancement

Descripción de la vacante

ITRex Group is seeking a senior Java engineer to join a team in the middle of a significant AI transformation. You will build a Spring Boot microservices backend on Kubernetes and integrate AI into the development process, pairing daily with cross-functional teams including product, QA and DevOps.

Engagement runs through year-end with high extension probability. The role demands hands-on leadership, end-to-end feature ownership, and the ability to balance AI suggestions with production

Formación

• Proficient in Java 11/17 with modern features.
• Strong Spring/Spring Boot experience for backend services.
• Experience designing and evolving HTTP APIs.
• Experience with microservices architecture and data ownership.
• Relational databases design, indexing and migrations.
• Test automation including unit/integration tests.

Responsabilidades

• Design, build and own Spring Boot microservices and related Web APIs in Kubernetes.
• Take end-to-end ownership of features including schema, API contracts, tests and production behavior.
• Apply AI-assisted techniques across the development cycle with accountability for merged code.
• Help establish AI-assisted engineering practices and onboarding for new engineers.
• Pair with colleagues to tackle hard problems and share context.
• contribute to architectural decisions on service boundaries and data ownership.
• Maintain CI/CD pipelines with GitLab and Jenkins; ensure healthy builds and tests.
• Collaborate with product, QA and DevOps to convert ambiguous requirements into shippable outcomes.
• As a lead, set technical direction and mentor engineers.

Conocimientos

Core Java

Spring Framework

Web API design

Microservices

SQL/Relational DB

Automated testing

CI/CD

AI-assisted development

Pair programming

English proficiency

Herramientas

Docker

Kubernetes

Maven

GitLab/Jenkins

Terraform

PostgreSQL

MySQL

Descripción del empleo

THE PLACE

ITRex - AI pioneers who build systems that actually work in the real world, not just in demos. We're 250+ people spread across the US and Europe, creating solutions for companies like Procter & Gamble and Shutterstock. We keep it simple, build it right, and focus on what works.

About ITRex

ITRex - AI pioneers who build systems that actually work in the real world, not just in demos. We're 250+ people spread across the US and Europe, creating solutions for companies like Procter & Gamble and Shutterstock. We keep it simple, build it right, and focus on what works.

THE PEOPLE

We're the kind of people who don't ignore messages in Slack, who jump in to help when you're stuck on a problem, and who offer solutions instead of blame when things go sideways. We believe in openness, accountability, and having each other's backs. No office politics, no hidden agendas - just people who care about doing good work together and supporting each other to get there.

THE ROLE

We are looking for a senior Java engineer to join a team in the middle of a serious AI transformation, building a Spring Boot microservices backend on Kubernetes and bringing AI into the whole development process - so we need someone who already works this way, can judge when an AI suggestion helps versus quietly introduces a bug, and wants to help shape that practice for the team, working daily in pair programming and a cross-functional group alongside product, QA and DevOps. The engagement runs to the end of the year, with a high probability of extension.

Your Responsibilities

• Design, build and own Spring Boot microservices and the Web APIs around them, from the data model through to what runs in Kubernetes
• Take end-to-end responsibility for the features you ship: schema, service, API contract, tests, pipeline and the behaviour in production
• Use AI assistance deliberately across the development cycle - design exploration, implementation, refactoring, tests, review - and stay accountable for everything that gets merged
• Help establish the team's AI-assisted engineering practice: what works, what to avoid, where a human review gate belongs, and how new joiners get up to speed with it
• Pair with other engineers on hard problems and share context instead of hoarding it
• Contribute to architectural decisions on service boundaries, communication patterns and data ownership, and argue your position clearly when you disagree
• Keep the build pipeline healthy: GitLab and Jenkins stages, test suites, container builds and Terraform-managed infrastructure
• Review other people's code with the same care you want applied to your own
• Work directly with product, QA and DevOps to turn ambiguous requirements into something shippable, rather than waiting for a fully specified ticket
• As a lead, set technical direction on your part of the system and mentor the engineers around you

Requirements

Our Expectations

• Core Java: Java 11 and Java 17, the concurrency model, collections, memory behaviour and the language features that actually changed how modern services are written
• Solid, production-grade experience with the Spring Framework and Spring Boot: dependency injection, configuration, Spring Data, Spring Security, REST controllers and the testing support
• Web API development: designing, versioning, documenting and evolving HTTP APIs that other teams depend on
• Microservice architecture: service decomposition, inter-service communication, resilience patterns, data ownership, and an honest sense of when a microservice is the wrong answer
• SQL and relational data modelling with PostgreSQL and MySQL - schema design, indexing, query tuning and migrations
• Automated testing as a habit: JUnit, Mockito, integration tests and the judgement to know what deserves coverage
• Maven for build and dependency management
• Docker, and Kubernetes at the level of someone who deploys onto it and debugs on it - how workloads, services, config, secrets and resource limits fit together. Running the cluster itself is not your job
• Terraform and infrastructure as code
• CI/CD with GitLab and Jenkins: pipelines you can read, extend and fix
• Practical experience with AI-assisted software development, and genuine interest in driving that practice forward inside the team
• Willingness to work in pair programming
• Strong communication skills and a track record in cross-functional teams; you enjoy solving problems together rather than working through tickets alone
• English at B2 level or above

Nice to have

• Observability in practice: Grafana dashboards, Kibana and the ELK stack, Sentry for error tracking
• Structured logging and alerting design - deciding what a service should say about itself and when someone should be woken up
• Performance testing and profiling of JVM services under load
• Experience introducing AI-assisted workflows to a team: prompt and context practices, review discipline, guardrails for generated code
• Prior work in a lead or tech-lead capacity on a distributed backend

Benefits

What We Offer

Why people stay

First, the foundation:

• Remote flexibility: Work where and how you work best - we trust you to deliver
• Fair compensation: Competitive salary + benefits that matter (medical, wellness, learning)

Then, the growth:

• Ownership opportunities: See a problem worth solving? Own it. We back smart risks over bureaucratic safety
• AI enhancement: We leverage AI to make you faster and stronger - complementing your abilities, not replacing them
• Learning investment: English classes, professional development, well-being support
• Career progression: Real paths up, not just sideways shuffling

Finally, the people:

• Responsive teammates: No ignored Slacks, no "not my problem" attitudes
• Supportive culture: When you're stuck, people help. When things break, we fix them together
• Human connections: Regular meetups, tech talks, and actual relationships beyond work