Senior Python Engineer (Remote)

About the role

We are seeking a Senior Python Engineer to own and evolve the transaction‑monitoring component of the Crystal platform. The role is fully remote, open to candidates across Europe, and sits within the Nexus squad that streamlines client operations and investigations.

Key responsibilities

• Own the transaction‑monitoring services, ensuring reliability and observability.
• Maintain and improve code quality through continuous development, testing, and refactoring.
• Design and implement end‑to‑end features from specification to production.
• Perform performance optimisations, including database query tuning.
• Conduct code reviews and provide constructive feedback to teammates.
• Collaborate on scaling distributed systems and enhancing platform stability.

Required profile

• 8+ years of commercial experience building Python backend services and APIs.
• Strong software architecture expertise.
• Deep knowledge of SQL/NoSQL databases, especially PostgreSQL.
• Solid understanding of testing principles at multiple system levels.
• Experience delivering client‑facing solutions in distributed environments.
• Product‑oriented mindset and fluent English communication.

Required skills

• Python (3.14)
• Flask
• Granian
• PostgreSQL
• Redis
• RabbitMQ
• ClickHouse
• Kubernetes
• AWS
• Hetzner
• Datadog
• Grafana

What we offer

• Fully remote work from anywhere in Europe.
• Access to an AI development tool of your choice (Cursor or Claude Code).
• Opportunity to work on cutting‑edge transaction‑monitoring technology within a fast‑growing fintech environment.