
We are looking for a talented Senior Python Engineer to join our Platform & 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.
More details: crystalintelligence.com
Duties and responsibilities:
Performance improvements, database query optimisation, and scalability enhancements;
Monitoring and observability configuration and best practices;
Managing and developing internal libraries;
Development pipeline improvements, like code coverage tooling integration, in close collaboration with the DevOps team;
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;
Refactoring code as necessary.
Required:
8+ years of commercial experience developing Python backend services and APIs for the web;
Solid software architecture skills;
Experience with distributed systems;
Strong knowledge of SQL/NoSQL databases and data architecture, including PostgreSQL;
Experience with the Flask framework;
Experience in performance optimisation (database query optimisation, caching);
Understanding of integration processes with external services;
Product-oriented mindset;
Proficiency in English.
Would be a plus:
Experience with ClickHouse;
Experience with systems operating on large data volumes;
Experience designing AI-enabled developer environments;
Experience writing raw SQL queries;
Experience designing and leading major reworks of complex distributed systems;
Experience with Rust;
Passion for Bitcoin and blockchain technologies.
No previous knowledge of Blockchain technology required.
Tech stack:
Redis, RabbitMQ, PostgreSQL, ClickHouse;
Kubernetes, AWS S3;
Python 3.14, Flask, Granian;
Datadog, Grafana.
You’ll get:
AI tool of your choice: Cursor or Claude Code.

Crystal is a leading blockchain intelligence firm empowering financial institutions, law enforcement and regulators with real-time blockchain analysis, investigative and compliance solutions.
Our solution helps financial institutions comply with global anti-money laundering regulations efficiently. Investigators and government agencies leverage Crystal’s cutting-edge technology and unique real-time intelligence to solve crypto investigations. Available as a free blockchain explorer, SaaS, or API.