Senior Python Backend Developer (Services)

About the role

payabl. is looking for a Senior Python Backend Developer to join its engineering team and help evolve the company’s backend service architecture.

This role focuses on building reliable, scalable Python microservices while modernising existing systems. You will work with legacy codebases, identify and extract business logic, and reimplement that functionality within cleaner, more maintainable service-based architectures.

The position requires strong backend engineering fundamentals, careful attention to reliability, and a practical approach to solving complex production problems. You will take ownership of services from initial design through deployment and ongoing operation.

The role reports to the Engineering Lead.

What you’ll be doing

• Design, develop and maintain high-performance backend services using Python.

• Build asynchronous microservices using FastAPI and AsyncIO.

• Analyse legacy applications and identify business logic that should be migrated into modern services.

• Refactor and modernise existing backend modules.

• Improve the maintainability, scalability and reliability of legacy functionality.

• Design services with idempotency, fault tolerance and robust error handling.

• Integrate external APIs and third-party services.

• Handle API failures, retries and edge cases reliably.

• Implement and maintain webhooks and callback-based integrations.

• Design retry mechanisms for asynchronous and distributed workflows.

• Write and maintain unit and integration tests.

• Ensure services behave correctly under failure and recovery scenarios.

• Collaborate with engineering, product and infrastructure teams.

• Contribute to architectural discussions and technical improvements.

• Identify opportunities to improve service performance and reliability.

• Take end-to-end ownership of backend services from implementation through production support.

What we’re looking for

• At least five years of professional backend-development experience.

• Strong professional experience developing backend systems with Python.

• Deep knowledge of AsyncIO.

• Strong experience using FastAPI.

• Experience building non-blocking and asynchronous backend services.

• Proven experience designing reliable microservices.

• Strong knowledge of relational databases.

• Experience working with MySQL.

• Experience working with PostgreSQL.

• Solid understanding of REST API design and third-party integrations.

• Experience implementing webhooks and callback workflows.

• Experience designing robust retry strategies.

• Strong knowledge of unit and integration testing.

• Experience working with legacy systems.

• Proven ability to migrate legacy functionality into modern architectures.

• Strong analytical and technical problem-solving skills.

• The ability to work independently within an established architecture.

• A strong sense of ownership and accountability for production services.

• A focus on correctness, resilience and long-term maintainability.

Skills that would be an advantage

• Experience working with PHP.

• Experience with Perl.

• Familiarity with JavaScript.

• Experience using Apache Kafka.

• Experience with Redis.

• Knowledge of event-driven architecture.

• Exposure to CI/CD pipelines.

• Experience with Docker.

• Familiarity with Kubernetes.

• Previous experience in fintech, payments or e-commerce.

• Knowledge of payment gateways.

• Experience with 3D Secure.

• Knowledge of payment tokenisation.

• Previous involvement in large-scale technology migrations.

• Experience moving systems between different languages, frameworks or architectural approaches.

Engineering environment

The engineering environment places a strong emphasis on reliability, ownership and practical technical decision-making.

Developers work within a defined architectural direction while retaining ownership over implementation details. The team values clean engineering practices, measurable improvements and the adoption of new technologies where they provide clear value.

Dedicated DevOps support is available, with opportunities for engineers to contribute to infrastructure and deployment processes where appropriate.

Work arrangement

This is a fully remote contractor position available to candidates based in:

• Portugal

• Ukraine

The role operates under a contractor arrangement.

Candidates should confirm contractual terms, eligibility and specific working arrangements directly with payabl. during the recruitment process.

Recruitment process

The expected hiring process includes:

1. Talent Acquisition and technical screening – An initial conversation covering your background, experience and motivation, together with a short technical assessment.

2. Practical technical assessment – A session with the Team Lead and technical specialists that may include live coding or a realistic backend-engineering scenario.

3. Final interview – A discussion with senior Technology leadership, potentially including the CTO, CPO and Team Lead, focused on collaboration, expectations, team fit and the wider technical environment.

The exact process may vary depending on the applicant.

About payabl.

payabl. is a financial-technology and payments company providing payment and banking services to businesses across international markets.

The company is developing payabl.one, a unified platform that brings together global payments, multi-currency accounts and other financial services.

Its engineering teams build and maintain the backend services and infrastructure that support payment processing, integrations and financial operations.

How to apply

Applicants should submit an up-to-date CV through payabl.’s official careers page.

Your application should clearly demonstrate:

• Your total professional backend-development experience.

• Your experience using Python in production.

• Services you have built with FastAPI and AsyncIO.

• Asynchronous or non-blocking systems you have designed.

• Microservices you have developed or maintained.

• Legacy systems you have modernised or migrated.

• Your experience with MySQL and PostgreSQL.

• External APIs, webhooks or callback integrations you have implemented.

• Retry, fault-tolerance and idempotency strategies you have designed.

• Your unit and integration testing experience.

• Any work with Kafka, Redis, Docker or Kubernetes.

• Experience in fintech, payments or e-commerce.

• Any exposure to 3DS, payment tokenisation or payment gateway integrations.

Applications are processed directly by payabl. cyprustech.careers is presenting this vacancy for informational purposes and is not acting as the employer or recruitment agency for this position.