Remote Senior Python Backend Engineer - Fintech Microservices

payabl.; Lisboa; On-site; EUR 70,000 - 110,000; Full time

Job summary

payabl. is seeking a Senior Python Backend Developer to join our engineering team. You will design, build, and evolve a high-performance service layer with microservices, while converting legacy systems to modern Python services.

The role is remote from Portugal or Ukraine, with reporting to the Engineering Lead. You will own services end-to-end, implement robust error handling, and contribute to architecture decisions in a fast-growing fintech environment.

Qualifications

• 5+ years of backend development experience with strong Python expertise.
• Deep knowledge of AsyncIO and FastAPI.
• Experience building non-blocking, high-reliability microservices.
• Relational databases like MySQL or PostgreSQL.
• Solid API design and third-party integrations.
• Experience with webhooks and retry strategies.
• Strong testing practices and legacy systems migration.

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 reliability with idempotency, fault tolerance, and robust error handling.
• Design and integrate external APIs with retries and edge-case handling.
• Write unit and integration tests and collaborate across teams.
• Own services end-to-end from design to production.

Skills

Python

FastAPI

AsyncIO

Microservices

Relational DB

API design

Testing

Legacy migration

Tools

Docker

Kubernetes

PostgreSQL

MySQL

Job description

payabl. is seeking a Senior Python Backend Developer to join our engineering team. You will design, build, and evolve a high-performance service layer with microservices, while converting legacy systems to modern Python services.

The role is remote from Portugal or Ukraine, with reporting to the Engineering Lead. You will own services end-to-end, implement robust error handling, and contribute to architecture decisions in a fast-growing fintech environment.