Senior Python Backend Engineer - Remote Fintech Services

payabl; Warszawa; On-site; PLN 200,000 - 280,000; Full time

Benefits offered by this job

Remote from Poland

Contractor arrangement

Job summary

payabl. invites a Senior Python Backend Developer ( Services ) to join our engineering team and evolve the service layer with reliable, scalable microservices.

This remote-from-Poland contractor role focuses on extracting business logic from legacy systems and reimplementing it as modern Python services, with emphasis on correctness, resilience, and maintainability. You’ll own services end-to-end, from design to production, and collaborate across teams.

Qualifications

• 5+ years of backend development experience.
• Strong Python expertise with AsyncIO and FastAPI.
• Experience building non-blocking microservices.
• Solid relational database knowledge (PostgreSQL/MySQL).
• Experience with API design and webhook integrations.

Responsibilities

• Design, build, and maintain high-performance Python microservices (FastAPI, AsyncIO).
• Analyze legacy systems and extract business logic into modern architectures.
• Refactor and migrate modules into clean, scalable services.
• Ensure system reliability with idempotency and robust error handling.
• Design and integrate external APIs and retries.
• Implement and manage webhooks and retry mechanisms.
• Write high-quality unit and integration tests.
• Collaborate with cross-functional teams for stability and performance.
• Contribute to architectural discussions and improvements.
• Take ownership of services end-to-end from design to production.

Skills

Python

AsyncIO

FastAPI

Microservices

Unit testing

Tools

PostgreSQL

MySQL

Docker

Kubernetes

Job description

payabl. invites a Senior Python Backend Developer ( Services ) to join our engineering team and evolve the service layer with reliable, scalable microservices.

This remote-from-Poland contractor role focuses on extracting business logic from legacy systems and reimplementing it as modern Python services, with emphasis on correctness, resilience, and maintainability. You’ll own services end-to-end, from design to production, and collaborate across teams.