Senior Backend Python Engineer (Gateway)

payabl. is a company powering the growth of merchants by helping them take payments easily, securely, and globally. The Gateway Related Projects team focuses on designing, developing, and implementing payment solutions that ensure stable and consistent payment processing.

• 5+ years of backend engineering experience with deep Python expertise, preferably with FastAPI and AsyncIO.
• Willingness and eagerness to work with Perl production code.
• Experience building and scaling microservices architectures and high-throughput systems.
• Strong knowledge of integrating third-party APIs managing webhooks, callbacks, idempotency, and retry policies.
• Experience with Docker/Containerization and solid grasp of AWS cloud infrastructure (Lambda, SQS/SNS, cloud networking).
• Familiarity with event-driven architecture and messaging systems (e.g., Kafka, RabbitMQ).
• Strong English communication skills, both written and verbal.
• Track record of owning features from design to production and mentoring other engineers.
• Commitment to writing clean and intentional code, not relying on AI-generated snippets.

• Support and extend the existing Perl-based payment gateway.
• Design and build high-performance microservices in Python.
• Architect and implement scalable, distributed Python services to replace legacy components.
• Integrate and manage complex third-party APIs and external payment services.
• Lead code reviews, drive engineering best practices, and identify system bottlenecks.
• Collaborate with DevOps to improve CI/CD pipelines using GitLab.
• Architect solutions using AWS services such as Lambda and ECS.
• Troubleshoot and resolve complex production issues in distributed systems, maintaining "zero-downtime" mentality.
• Bring a product mindset to understand business logic and user impact.

Contract type will be assessed based on location and discussed during the initial interview. The role is remote from Portugal or Poland under a contractor arrangement.