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: crystalintelligence.com
Key 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.
About Crystal Intelligence
Crystal Intelligence, founded in 2018 as Crystal Blockchain within Bitfury Group and headquartered in Amsterdam with offices in London, provides blockchain analytics for compliance, investigations and risk monitoring. Its platform traces transactions across Bitcoin, Ethereum and numerous chains, linking addresses to entities, scoring risk and generating alerts for exchanges, banks and regulators. Used by financial intelligence units and VASPs to meet AML and Travel Rule obligations, Crystal combines clustering heuristics with case-management workflows. Now operating independently as Crystal Intelligence, the company serves institutions worldwide and is backed by Bitfury and leading investors. The team emphasizes accuracy, explainability and regulator-ready reporting. Expect a detail-oriented culture that values investigative rigor, data quality and helping make crypto markets safer and more transparent today.