Java Engineer

FlixBus; Warszawa; Hybrid; PLN 248,000 - 358,000; Full time

Benefits offered by this job

Work from (M)Anywhere

Hybrid work model

Wellbeing support

Learning & Development

Mentoring Program

Job summary

Flix is seeking a skilled Java Engineer for a service agreement collaboration (B2B) to join the Network Planning team at FlixTrain. You will design, build and maintain backend services, APIs and event-driven integrations to automate workflows and optimize timetable and vehicle allocation.

This greenfield environment offers room to shape new products and drive technical quality. You will work in a cross-functional distribution, focusing on reliable APIs, data models, and collaboration with

Qualifications

• 3–5 years of backend experience in Java/JVM
• Experience in AWS and event-driven systems (Kafka)
• Strong English and Agile experience

Responsibilities

• Design, develop and deliver backend services and APIs for FlixTrain workflows
• Build and evolve data models and asynchronous integrations between services
• Work with internal users, product and engineers to translate needs into solutions
• Write automated tests to ensure reliability and maintainability
• Collaborate with engineers across a distributed architecture in an Agile environment
• Document technical decisions and ways of working

Skills

Java

Kotlin

English skills

Agile

Tools

Spring Boot

AWS

Kafka

Kubernetes

Terraform

GraphQL

PostgreSQL

GitLab CI

Job description

We are looking for a skilled Java Engineer for service agreement collaboration (B2B contract) to cooperate with a team dedicated to Network Planning at FlixTrain - building internal tools that help plan the timetable and vehicle allocation, reduce manual processes, and increase productivity. This is a greenfield environment with plenty of room to shape new products from the ground up and explore innovative solutions for our internal users.

Scope of Services

You will independently design, develop and deliver reliable backend services within a self-organized, cross-functional, distributed team. This includes building robust APIs and event-driven integrations for our internal tools, with a strong focus on internal user needs. You will also help drive backend architecture decisions and contribute to technical quality across teams through code reviews and close collaboration.

About the Engagement

• Design, build and maintain backend services and APIs that automate and simplify FlixTrain Network Planning workflows
• Develop and evolve data models and integrations, including asynchronous, event-driven communication between services
• Work with internal users, product and other engineers to understand their needs and turn them into practical technical solutions
• Write and maintain automated tests to ensure the reliability and maintainability of the services you deliver
• Collaborate with other engineers across a distributed architecture within an Agile environment
• Document technical decisions, solutions and ways of working
• Our backend stack:
  • Java with Spring Boot
  • AWS
  • Kafka
  • Kubernetes
  • Terraform for IaC
  • GraphQL
  • PostgreSQL
  • GitLab CI

About You

• You have 3 to 5 years of experience building backend applications, from which a couple of years building backend applications in Java or another JVM language such as Kotlin
• You have worked in cloud environments (ideally AWS)
• You have practical experience with at least one of the following:
  • Building and running on AWS
  • Designing, building and maintaining event-driven systems with Kafka
  • Deploying and operating workloads on Kubernetes
  • Managing infrastructure as code, ideally with Terraform
• You write automated tests as a natural part of your development process and care about code quality and maintainability
• Understanding of event-driven systems and how to work with them
• Solid written and spoken English skills
• Experience working in an Agile setup
• Curiosity about the business domain. Interest in transportation, logistics or similarly complex domains is a good signal, as is the ability to explain such a domain clearly

Nice to have

• Experience building services with Spring Boot
• Experience working with databases, relational and/or NoSQL
• Experience with CI/CD pipelines (GitLab CI or GitHub Actions)
• A DevOps mindset: you are willing to own pipelines, infrastructure and quality, not just the application code
• Experience with agentic or AI-assisted coding

What We Offer

• Work from (M)Anywhere: Depending on your role, work from another location for up to 60 days per year.
• Hybrid work model: We are an office-first company, but we offer flexibility to balance work and life.
• Wellbeing support: Access confidential 1:1 counselling, courses, and stress management for yourself and up to four family members.
• Learning & Development: Take advantage of language classes, training courses, and expert-led sessions to grow your skills.
• Mentoring Program: Connect with experienced colleagues to gain insights and accelerate your career.

At Flix, we empower our teams to push boundaries and shape the future of mobility. As we continue to scale globally, we harness cutting-edge technology to make mobility smarter, more sustainable, and more affordable.

If you’re looking for a place where you can drive change and redefine how millions of people travel, Flix is the place where you can lead your journey!

This is a Poland-based position. Are you currently based in Poland?

Are you open to a B2B collaboration model?

Do you require visa/residence sponsorship to be employed in Poland?

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