Senior Python Engineer

b3consultingpoland; Kraków; Hybrid; PLN 180,000 - 260,000; Full time

Benefits offered by this job

Health and sports benefits

Speed Coaching

Sports training

Team events

Development-focused meetups

Job summary

b3consultingpoland is seeking a Senior Python Engineer to join our Kraków-based team. You will design, build, and scale backend services in a SaaS setting, focusing on robust REST APIs and data-driven features for international collaboration.

You will work with product teams to translate requirements into reliable software, perform thorough testing, and mentor peers while leveraging AI-assisted tools for code reviews and innovation.

Qualifications

• Hands-on senior-level engineering experience building back-end systems.
• Strong Python fundamentals and Django development experience.
• Relational databases (PostgreSQL) with optimized queries and schema management.
• Experience architecting and delivering scalable REST APIs.
• Solid testing practices (unit/integration) focused on numerical/analytic logic.
• Comfort with applied statistics (regressions, distributions, p-values) and modeling.
• Daily use of AI coding assistants (Cursor, Copilot, Claude Code).
• Fluent written and spoken English for international collaboration.

Responsibilities

• Design, develop, and expand scalable backend services, modules, and REST APIs within a SaaS architecture.
• Implement, verify, and continuously test analytical and statistical algorithms to guarantee full correctness and output accuracy.
• Analyze business and technical requirements in close collaboration with product teams, engineering peers, and Tech Leads.
• Perform code reviews for other engineers — including solutions created with AI assistance — and provide mentorship to support team growth.
• Maintain system stability, execute data migrations, manage complex operations on large datasets, and handle infrastructure upgrades.
• Diagnose, analyze, and efficiently resolve technical issues and production bugs.
• Actively adopt AI developer tools in daily workflows and propose concepts for new AI-powered product features.

Skills

Python

Django

PostgreSQL

REST APIs

Unit & integration tests

Statistics

AI tools

English

Mentorship

Backend engineering

Tools

Cursor

GitHub Copilot

Claude Code

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 Senior Python Engineer.

Your responsibilities

• Design, develop, and expand scalable backend services, modules, and REST APIs within a SaaS architecture.
• Implement, verify, and continuously test analytical and statistical algorithms to guarantee full correctness and output accuracy.
• Analyze business and technical requirements in close collaboration with product teams, engineering peers, and Tech Leads.
• Perform code reviews for other engineers — including solutions created with AI assistance — and provide mentorship to support team growth.
• Maintain system stability, execute data migrations, manage complex operations on large datasets, and handle infrastructure upgrades.
• Diagnose, analyze, and efficiently resolve technical issues and production bugs.
• Actively adopt AI developer tools in daily workflows and propose concepts for new AI-powered product features.

Requirements

• Hands-on senior-level engineering experience building back-end systems.
• Strong Python fundamentals and commercial experience developing applications with Django.
• Proficiency with relational databases (such as PostgreSQL), including writing optimized queries and schema management.
• Experience in architecting, designing, and delivering scalable REST APIs.
• Solid testing practices (unit and integration tests) with a focus on verifying numerical and analytical logic.
• Readiness to work with applied statistics (regressions, distributions, p-values) and implement models alongside domain experts.
• Daily experience using AI coding assistants (such as Cursor, GitHub Copilot, or Claude Code).
• Professional fluency in written and spoken English for seamless collaboration in an international team.

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.