We’re expanding our engineering team and hiring a Senior Python Software Engineer to help own and develop an established trading-related application. The system runs in production, processes high-frequency real-time data, and needs careful performance engineering and disciplined testing to keep latency and reliability where they should be.
You’ll take meaningful ownership day-to-day, partnering closely with the founder and the engineering team to prioritise work, ship improvements quickly, and keep the system fast, reliable, and correct.
Location: UK-based preferred
Working style: Mostly remote, occasional in-person days for planning/coordination
Support: Availability during core market hours when needed
What You’ll Do
* Own and improve a production Python codebase that runs during market hours.
* Build and optimise real-time data pipelines (throughput, p50/p99 latency, jitter).
* Do profiling-driven performance work across ingestion → compute → messaging → consumers.
* Improve reliability: freshness/staleness handling, safe degradation, back pressure, fault isolation.
* Strengthen “developer leverage”: replay/simulation tools, regression tests, and debugging tooling.
* Work with cloud infrastructure, deployment, monitoring, and incident response.
* Collaborate directly with the founder and engineering team on architecture and roadmap.
Essential Skills
* 5+ years professional Python experience; you’ve shipped and owned production systems.
* Built/owned a real-time / low-latency system (not batch ETL) with measurable performance goals.
* Strong understanding of async + multiprocessing tradeoffs and performance profiling.
* Comfortable owning an existing codebase: refactors, tests, architecture improvements.
* Experience with messaging / event-driven systems and strong API/schema discipline.
* Production ownership mindset: incidents, monitoring, and fast debugging when it matters.
* UK-based preferred and able to support core market hours when required.
Desirable Skills
* Experience with trading, market data, or execution systems.
* Familiarity with Interactive Brokers TWS or other brokerage APIs
* Experience designing safety constraints/guardrails in automated systems.
What We Offer
* Competitive salary (negotiable) + performance-related bonus.
* Mostly remote, with some in-office collaboration days for coordination and planning
* Lean environment, direct impact on a live system.
* High ownership and influence over system design and roadmap.