Back-End Engineer, Trading

Blockchain.com seeks a Back-End Engineer, Trading in London (office 4 days/week) to build Kotlin/Python backend services for a cryptocurrency trading platform, including order management, market data, REST APIs, and WebSocket streams.

Blockchain.com is connecting the world to the future of finance. Since its inception in 2011, it has earned the trust of over 90 million wallet holders and more than 40 million verified users, facilitating over $1 trillion in crypto transactions. As a Back-End Engineer on the Cryptocurrency Trading Platform, you will build the backend services that power internal and external trading products — from order management and market data processing to the REST APIs and WebSocket streams that serve web and mobile clients. What you will do: - Design, build, and operate backend services in Kotlin and Python that power trading products, from core trading workflows to client-facing APIs - Develop and improve services for order management, market data processing, and trade lifecycle handling in a real-time, high-volume environment - Build and maintain REST APIs and WebSocket streams that deliver real-time prices, order updates, and account data - Collaborate with cross-functional teams — product, frontend, trading — to adapt the platform quickly to new features and market conditions - Ensure high availability, reliability, and scalability of trading services, with a sharp focus on latency, observability, and testing - Contribute to architecture discussions and technical decisions, writing clean, maintainable code and sharing knowledge across the team

Professional experience building backend services, ideally in Kotlin and/or Python. Solid experience designing and building backend services and REST APIs; experience with WebSockets or other real-time streaming protocols such as NATS/JETSTREAM is a plus. Working knowledge of SQL and experience integrating with multiple internal or third-party services. An understanding of performance fundamentals — identifying bottlenecks, managing latency, and building systems that stay responsive under load. Strong problem-solving skills and clear communication with both technical and non-technical colleagues. Curiosity and enthusiasm for learning new technologies; interest in financial markets or crypto is a plus, not a requirement. Familiarity with Docker/Kubernetes and cloud environments (AWS) is a plus.

London (office 4 days/week).