Senior Fullstack Software Engineer (Python/Java) - Service Agreement

Company: Flix

Location: Warsaw, Masovian Voivodeship, Poland

Salary: PLN 135 – PLN 170 an hour

Work arrangement: Remote possible

Employment type: Contract

Experience: 5-10 years

Posted: 2026-10-26

Responsibilities

Develop and maintain scalable contact center applications using Python and Java. Design user-focused solutions and contribute to business objectives through efficient workflows and modern technology stacks.

Requirements

Requires a minimum of 5 years of professional experience in full-stack development with expertise in Python and Java. Candidates must be comfortable with Agile methodologies, automated testing, and system architecture.

Skills

  • Python
  • Java
  • Full-stack development
  • System design
  • Architecture
  • Legacy product migration
  • Agile methodologies
  • Automated testing
  • Test runners
  • Quality assurance
  • Contact center applications
  • Automation

About this role

Rate: 135 – 170 PLN/hour (B2B)
We are looking for an experienced Software Engineer to join Flix on a freelance/service agreement basis (B2B contract). This is a contractor engagement for a seasoned professional with a full-stack mindset.
Scope of Services
Developing Flix’s contact center applications, with a focus on scalable agent-facing interfaces and automation. The role will involve extensive discovery to identify the most efficient and effective workflows.
Our tech stack
About the Engagement
Deliver solutions for a defined portfolio of products, contributing to business objectives.
Design and develop user-focused solutions tailored to product requirements and user needs.
Apply Agile methodologies to organize and execute the development process.
Develop and enhance products using modern technology stacks.
Make technical decisions within the scope of services provided, promoting technical excellence and consistency across solutions.
About You
Minimum 5 years of professional experience in full-stack development, with a focus on architecture, system design, and legacy product migration.
Extensive experience with Python and its ecosystem for the development of new products.
Solid knowledge of Java for the maintenance and further development of existing products.
Strong focus on quality assurance practices and technical standards throughout the product development lifecycle.
Hands-on with automated testing and experience with different test runners.
Comfortable with Agile methodologies in planning and executing development work.
Cooperation model
Cooperation based on a service agreement (B2B/freelance contract), not an employment contract.
You will operate as an independent contractor, responsible for delivering agreed services and submitting invoices
Location: open for contractors based in Poland

About Flix

Software Development · 1,001-5,000 employees · headquartered in Munich, Bavaria · founded 2011

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