Founding Backend Engineer Mission QFEX is building a team of founding engineers who can design, code and own systems that will soon process billions of dollars in trading volume every single day. This is an incredible opportunity to work alongside a very well-backed team of builders from some of the biggest financial companies in the world (Citadel, Kraken, Tower Research Capital) and change the course of financial history. What You’ll Do Reliability & performance \ Design fault-tolerant, low-latency, always-available services; write load tests and chaos suites; tune until p99 is boring. Developer experience \ Set up and maintain CI/CD, IaC, monitoring, and on-call processes that future teammates will thank you for. Technical direction\ Evaluate tools, set coding standards, and guide architectural decisions as we scale. Culture & hiring\ Share and receive new knowledge and experiences, set impeccable cultural standards, and help interview the next engineers. What You’ll Need A STEM degree from a University that is highly ranked in your home country. Experience with a high-performance language like C or C++ . 3+ years building and running high-traffic or real-time production systems. The desire to create and impose a responsible culture of tests, metrics, and graceful degradation. Impeccable levels of trust in yourself and others, including the ability to make decisions in minutes, not days. UK work authorisation and willingness to work Monday–Friday from our central London office. Bonus points Fintech, exchange, or low-latency experience. Rust Deep Kubernetes or infrastructure-as-code experience. Cyber security and compliance know-how. Benefits Lunch allowance and regular company events. The ability to grow alongside some of the best minds in fintech, as well as set standards and culture. Brand-new office near Liverpool Street with top-tier hardware and a stocked kitchen. 25 days holiday + bank holidays.