Python Developer

b3consultingpoland; Warszawa; Hybrid; PLN 180,000 - 300,000; Full time

Benefits offered by this job

Health benefits

Sports benefits

Speed Coaching

Sports training

Team events

Job summary

b3consultingpoland in Poland is seeking an experienced Python Backend Developer to join a greenfield banking project. You will design, develop and maintain backends that present financial data using Python and PostgreSQL, building high-performance data processing pipelines.

You will create and maintain Python libraries, write unit and integration tests, and optimize queries for speed and accuracy. The role requires 5+ years in Python backend development, strong SQL skills, and good English for

Qualifications

• 5+ years of commercial experience in Python backend development for data-intensive applications.
• Experience with relational databases and writing optimized, high-performance SQL queries, specifically with PostgreSQL.
• Strong teamwork and communication skills for daily collaboration with remote teams.

Responsibilities

• Design, develop, and maintain application backends responsible for presenting financial data.
• Collaborate on internal Python libraries for efficient data processing and analysis.
• Create and maintain unit tests and integration tests to ensure data integrity and code quality.
• Identify performance bottlenecks and propose improvements to increase data flow efficiency, query speed, and accuracy.

Skills

Python

English communication

Teamwork

Education

STEM or Computer Science degree

Tools

PostgreSQL

SQL optimization

Job description

We are part of an international organization listed on Nasdaq Stockholm, operating in 11 countries. In Poland, we work with full autonomy. We independently choose our technologies, processes, and ways of working while maintaining the highest professional standards.

We deliver a wide range of IT projects in Poland and internationally, across multiple domains and technologies. This allows our consultants to develop their competencies and gain experience aligned with their professional ambitions.

Our collaboration is built around the CARE philosophy. For us, it means responsible project matching, transparent cooperation, and a long-term approach to professional growth.

Join us as Python Developer. Join a brand-new greenfield project in the banking sector, building high-performance Python and PostgreSQL backends from scratch to process massive financial databases.Grow in an environment that cares about your development as much as you do.

Your responsibilities

• Designing, developing, and maintaining application backends responsible for presenting financial data.

• Collaborating on the development of internal Python libraries focused on efficient data processing and analysis.

• Creating and maintaining unit tests and integration tests to ensure data integrity and code quality.

• Identifying performance bottlenecks and proposing improvements to increase data flow efficiency, query speed, and data accuracy.

Requirements

• At least 5 years of commercial experience in Python backend development for data-intensive applications.

• Experience with relational databases and writing optimized, high-performance SQL queries, specifically with PostgreSQL.

• Methodical problem-solving skills and ability to tackle complex data challenges.

• Good communication skills and ability to work effectively in a team environment.

• High-level English proficiency for daily collaboration with remote teams.

• Higher degree in STEM or Computer Science.

• You need to live in Poland and/or be eligible to work here.

What we offer

• Work in a Scandinavian culture built on logic and dialogue.

• Health and sports benefits tailored to your needs.

• Speed Coaching – short sessions that provide new perspectives and solutions.

• Sports training, an internal team, and opportunities to take part in competitions.

• Team events and development-focused meetups.