Python Backend Developer

Quick Facts

• Industry: Banking

• Rate: up to ~150 PLN/hour net + VAT (B2B)

• Work model: hybrid (max 1x/week in Warsaw)

Description

We are looking for a Python backend developer responsible for the development and maintenance of modern backend and integration solutions. You will design and build production REST APIs consumed by external systems and teams, ensuring code quality and documentation while working closely with analysts and architects.

Responsibilities

• Write high-quality code

• Design technical solutions

• Design and implement production REST APIs from scratch consumed by external systems/teams

• Build and maintain production REST APIs

• Create and maintain OpenAPI specifications as a contract

• Integrate with existing systems, including working with an existing database schema

• Optimize SQL queries and diagnose performance issues

• Run unit, integration, and contract tests using pytest

• Create technical documentation

• Coordinate technical discussions with receiving teams

• Collaborate with analysts and architects

Requirements

• Minimum 3 years of commercial Python development

• Excellent knowledge of FastAPI or Django REST Framework with its ecosystem (Pydantic, SQLAlchemy or Django ORM)

• Documented experience designing and production-deploying at least one API consumed by external systems/teams

• Strong REST API design skills (resource modeling, HTTP method semantics, response codes, versioning, idempotency)

• Experience creating OpenAPI specifications as the contract (not generated after the fact)

• Practical knowledge of machine authentication: OAuth 2.0 client credentials, JWT, API keys with rotation

• Good knowledge of SQL and relational databases, including query optimization

• Experience integrating with existing systems

• Ability to write automated tests with pytest (unit, integration, contract)

• Knowledge of containerization (Docker) and working with CI/CD pipelines

• Knowledge of Linux/Unix

• Knowledge of REST, SOAP and SQL

• Knowledge of tools: FastAPI, Uvicorn, Gunicorn, Anaconda

• Ability to write clear technical documentation

• Ability to run technical alignment with receiving teams

• Experience with JIRA and Confluence

• Fluent Polish

Benefits

• Competitive B2B rate up to ~150 PLN/hour net + VAT

• Hybrid work model (max 1x/week in Warsaw)