Python / Data Engineer

B3 Consulting Poland; Warszawa; On-site; PLN 180,000 - 280,000; Full time

Benefits offered by this job

Health benefits

Sports benefits

Speed Coaching

Team events

Development meetups

Job summary

B3 Consulting Poland is looking for a Python / Data Engineer to join a fin-tech project, building high-performance Python and PostgreSQL backends from scratch to process massive financial databases. You will grow in an environment that values your development as much as the team’s.

In this role you will design, develop and maintain backends for financial data, contribute to internal Python libraries, and ensure code quality through unit and integration tests while optimizing data flow and query

Qualifications

• At least 5 years of commercial experience in Python backend development for data-intensive applications.
• Strong experience with relational databases, writing optimized SQL queries, and deep understanding of PostgreSQL internals
• Experience with PySpark and Pandas for large-scale data processing
• Methodical problem-solving skills with a focus on transactional consistency and concurrency/multithreading.
• Higher degree in STEM or Computer Science.
• High-level English proficiency for daily collaboration with remote teams.

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.

Skills

Python backend

PostgreSQL

PySpark

Pandas

SQL optimization

English proficiency

Education

CS degree

Tools

PostgreSQL internals

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 / Data Engineer Join a project in the fin-tech 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.

• Strong experience with relational databases, writing optimized SQL queries, and deep understanding of PostgreSQL internals

• Experience with PySpark and Pandas for large-scale data processing

• Methodical problem-solving skills with a focus on transactional consistency and concurrency/multithreading.

• Higher degree in STEM or Computer Science.

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

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.