Senior Python Engineer (Remote)

**Position Summary:** We are looking for a talented Senior Python Engineer to join our team responsible for transaction monitoring and exploration. This is a fully remote role, and we welcome applications from anywhere in Europe. As part of our Nexus squad, you will play a critical role in streamlining clients’ operations and smoothing their investigations on the Crystal platform. More details: https://crystalintelligence.com **Duties and responsibilities:** - Owning the transaction monitoring part of the Crystal platform; - Improving stability and observability of the owned services; - Maintaining code to high-quality standards; - End-to-end feature design and implementation; - Coding, debugging, testing and delivering features and improvements in a continuous manner; - Providing code reviews, assistance and constructive feedback to other team members; - Performance optimizations (including database queries optimizations); - Refactoring code as necessary. **Required:** - 8+ years of commercial experience developing Python backend services and APIs for the web; - Solid software architecture skills; - Strong knowledge of SQL/NoSQL databases and data architecture, including PostgreSQL; - Knowledge of testing principles at different levels of the system; - Experience in developing client-facing solutions; - Experience with distributed systems; - Product-oriented mindset; - Proficiency in English. **Would be a plus:** - Experience with scalability and performance optimizations of large distributed systems. - Experience with systems operating on large data volumes; - Experience with the Flask framework; - Passion for cryptocurrencies and blockchain technologies. *No previous knowledge of Blockchain technology required.* **Tech stack:** - Redis, RabbitMQ, PostgreSQL, ClickHouse; - Kubernetes, AWS + Hetzner; - Python 3.14, Flask, Granian; - Datadog, Grafana. **You’ll get:** - AI tool of your choice: Cursor or Claude Code.