Senior Backend Engineer

Quick Facts

• Role: Senior Backend Engineer

Description

Design, develop, and maintain distributed backend services supporting payment authorization, financial ledgers, settlements, and other payment-related processes. Build scalable, secure, and reliable APIs and implement event-driven architectures and integrations between distributed services. Take responsibility across the full software development lifecycle, including production support, incident investigation, and continuous improvements.

Responsibilities

• Design, develop, and maintain distributed backend services for payment-related processes

• Build scalable, secure, and reliable APIs focused on performance, maintainability, and resilience

• Develop event-driven architectures and integrate distributed services

• Own backend solutions end to end: requirements analysis, technical design, implementation, testing, deployment, and production support

• Design and maintain domain events and ensure reliable data exchange

• Partner with engineering and product teams to define technical requirements and support architectural decisions

• Monitor production, investigate incidents, perform root cause analysis, and implement improvements

• Review code, mentor developers, and contribute to engineering standards and best practices

Requirements

• 5+ years of commercial backend development experience using Java, C#/.NET, Rust, or Node.js

• Practical experience with distributed systems and event-driven architectures

• Strong understanding of distributed systems concepts: consistency models, Saga patterns, idempotency, Outbox pattern

• Production-grade backend services and API development experience

• Hands-on CI/CD pipeline experience, production monitoring, and observability solutions

• Relational database knowledge, preferably PostgreSQL

• Automated testing experience: unit, integration, and contract testing

• Daily practical use of AI-assisted development tools (e.g., GitHub Copilot, ChatGPT, Claude, or similar)

• Ability to write clean, maintainable, well-tested code

• Very good English and Polish

Benefits

• Private medical care

• Sports card

• Training courses

• International working environment and international projects

• Small team

• Hybrid working model: preferably 1 day per week in the Warsaw or Cracow office