Senior Backend Engineer - AI-Driven, Open-Source & Scale

upside; Polska; Hybrid; PLN 232,000 - 296,000; Full time

Job summary

Upside, a software consultancy, seeks a Senior Backend Engineer to design, build, and scale backend systems for international clients. A Python-first environment with PostgreSQL, AWS, and Kubernetes emphasizes robust architecture and performance under real load.

The role combines ownership, collaboration with senior leaders, and opportunities to contribute to open-source projects. You’ll work in a small, autonomous team, solving mission-critical problems and shaping systems while expanding your

Qualifications

• 5+ years building web applications (preferably Python).
• Completed university degree in computer science, data science or similar field.
• Deep understanding of monoliths, microservices, and messaging patterns.
• Expert knowledge of PostgreSQL and performance optimization at scale.
• Practical experience with CI/CD, Docker, and AWS/GCP.
• Mindset: proactive, technology-driven, and ready to experiment.
• AI-Native: use tools like Claude or Cursor to move faster.
• English: Fluent (C1) for direct client collaboration.

Responsibilities

• Drive technical direction: Own the architecture and implementation of complex backend systems.
• Problem Solving: Identify systemic risks before they manifest and propose actionable workarounds.
• Consulting: Translate business needs into scalable technology with stakeholders.
• Mentorship: Share lessons learned to help the team level up.
• AI Integration: Lead AI-driven improvements in products and tooling.

Skills

Python

PostgreSQL

AWS

Docker

Kubernetes

Microservices

Monoliths

English (C1)

CI/CD

Open-source

Education

University degree in Computer Science or related field

Tools

Claude

Cursor

GitHub Actions

CI/CD tooling

Job description

Upside, a software consultancy, seeks a Senior Backend Engineer to design, build, and scale backend systems for international clients. A Python-first environment with PostgreSQL, AWS, and Kubernetes emphasizes robust architecture and performance under real load.

The role combines ownership, collaboration with senior leaders, and opportunities to contribute to open-source projects. You’ll work in a small, autonomous team, solving mission-critical problems and shaping systems while expanding your