Senior Python Engineer with Graph databases

Our client: Klarna

Location: Warsaw (hybrid work: 2-3 days in the office)

Rate: 170 - 195 PLN per hour

Cooperation model: B2B

Start date: ASAP

Duration: Long-term agreement

Recruitment process: 1 timed Abstract and Logical Reasoning Test (up to 15 minutes); 1 short interview (up to 30 minutes)

Technology stack: Python, AWS, FastAPI, Neo4j

Do you want to play a key role in revolutionizing the future of finance? Join Klarna - a global leader in deferred payments, with over 85 million active users and 2.5 million transactions processed daily! As a pioneer in modern payment solutions, Klarna is developing innovative methods that streamline the shopping experience, enhance transaction security, and expand the availability of purchasing options. 

We are looking for a Backend Python Engineer to join our Source Core team. You will work on our knowledge graph system (Source), which enables structured data management through change requests. Our stack includes FastAPI, Neo4j, and Redis, and we follow best practices for API design, versioning, and automation.

Your role is:

-> Develop and optimize our FastAPI-based backend with a focus on stability and performance.

-> Work with Neo4j to enhance structured data modeling and query efficiency.

-> Improve the change request workflow, ensuring seamless versioning and review processes.

-> Follow best practices in Python development, API design, and code documentation.

-> Collaborate with frontend and infrastructure teams to enhance overall system performance.

Your skills and experiences:

-> Strong experience (5+ years) with Python and FastAPI (or similar frameworks).

-> Familiarity with graph databases (Neo4j preferred) and relational databases.

-> Experience with REST API design, versioning, and dependency management (e.g., uv, ruff).

-> Understanding of asynchronous processing (Dramatiq, Celery, or similar).

-> Proficiency in cloud technologies, especially AWS.

-> Knowledge of CI/CD, containerization (Docker)

-> Language proficiency: Advanced English (minimum B2 level).

Our client offers:

+ Great opportunity for personal development in a stable and friendly large multinational company.

+ Career growth and additional education.

+ Company events.

+ Global Reach: Impact millions with seamless shopping and payments.

+ Flexible working hours.

If interested, please apply safely through this portal (application rules are in accordance with GDPR). Employment agency Nr 17138.