Senior Python Engineer (DevEx Team, Remote)

<p><strong>Position Summary:</strong></p><p>We are looking for a talented Senior Python Engineer to join our Platform &amp; Developer Experience team. This is a fully remote role, and we welcome applications from anywhere in Europe. As part of our Build squad, you will play a critical role in shaping the foundations of developer experience, scalability, and performance of the Crystal platform.</p><p>More details: <a target="_blank" href="https://crystalintelligence.com">crystalintelligence.com</a></p><p></p><p><strong>Duties and responsibilities:</strong></p><ul><li><p><span>Performance improvements, database query optimisation, and scalability enhancements;</span></p></li><li><p><span>Monitoring and observability configuration and best practices;</span></p></li><li><p><span>Managing and developing internal libraries;</span></p></li><li><p><span>Development pipeline improvements, like code coverage tooling integration, in close collaboration with the DevOps team;</span></p></li><li><p><span>Maintaining code to high-quality standards;</span></p></li><li><p><span>End-to-end feature design and implementation;</span></p></li><li><p><span>Coding, debugging, testing and delivering features and improvements in a continuous manner;</span></p></li><li><p><span>Providing code reviews, assistance and constructive feedback to other team members;</span></p></li><li><p><span>Refactoring code as necessary.</span></p></li></ul><p><br><strong>Required:</strong></p><ul><li><p><span>8+ years of commercial experience developing Python backend services and APIs for the web;</span></p></li><li><p><span>Solid software architecture skills;</span></p></li><li><p><span>Experience with distributed systems;</span></p></li><li><p><span>Strong knowledge of SQL/NoSQL databases and data architecture, including PostgreSQL;</span></p></li><li><p><span>Experience with the Flask framework;</span></p></li><li><p><span>Experience in performance optimisation (database query optimisation, caching);</span></p></li><li><p><span>Understanding of integration processes with external services;</span></p></li><li><p><span>Product-oriented mindset;</span></p></li><li><p><span>Proficiency in English.</span></p></li></ul><p><br><strong>Would be a plus:</strong></p><ul><li><p>Experience with ClickHouse;</p></li><li><p>Experience with systems operating on large data volumes;</p></li><li><p>Experience designing AI-enabled developer environments;</p></li><li><p>Experience writing raw SQL queries;</p></li><li><p>Experience designing and leading major reworks of complex distributed systems;</p></li><li><p>Experience with Rust;</p></li><li><p>Passion for Bitcoin and blockchain technologies.</p></li></ul><p><br><span><em>No previous knowledge of Blockchain technology required.</em></span><br><br><span><strong>Tech stack:</strong></span></p><div><ul><li><p><span>Redis, RabbitMQ, PostgreSQL, ClickHouse;</span></p></li><li><p><span>Kubernetes, AWS S3;</span></p></li><li><p><span>Python 3.14, Flask, Granian;</span></p></li><li><p><span>Datadog, Grafana.</span></p></li></ul><p><br><span><strong>You’ll get:</strong></span></p></div><div><ul><li><p><span>AI tool of your choice: Cursor or Claude Code.</span></p></li></ul></div>