Trading System Architect in London

A highly specialized engineer who will bridge the gap between our quantitative trading strategies and our core engineering implementation. We require a senior engineer with deep domain experience in trading systems to guide architectural decisions, ensuring our systems are optimized for market microstructure, latency, and risk safety.

You will act as a high-level technical advisor and individual contributor, validating our architectural path and preventing costly domain-specific mistakes. Your voice will be crucial in defining the system architecture and making technical decisions to ensure optimized order execution.

We value domain experience over raw coding volume. We prefer a solid engineer who has spent years strictly in the trading domain and understands "why" systems fail, over a rockstar developer who has only worked in generic tech. You are pragmatic, focusing on stability and predictable latency over theoretical perfection.

• Lots of data – processing millions of transactions and market pairs data points daily
• Technical complexity – integrating with various exchanges requires careful design and essential monitoring systems to ensure a robust platform
• Scalability – developing solutions to efficiently process and store millions of transactions for subsequent analysis
• Latency – reducing communication latency across multiple physical regions to a minimum

• Over 5 years of experience working at an HFT firm, market maker, algorithmic trading firm, or top crypto exchange with trading-related responsibilities.
• Considerable expertise in developing systems with sub‐millisecond order execution.
• JVM language development background with deep knowledge of the JVM internals.
• Experience in building system architecture for trading systems.
• Familiarity with FIX, WebSocket, and REST API limitations in a trading context.
• Good theoretical knowledge of spot and futures trading internals.
• Proven ability to analyze and solve complex technical problems.
• Familiarity with multithreading concepts and distributed computing.
• Self‐motivated with a strong sense of ownership, capable of working independently with minimal supervision.
• Great communication skills with both technical and non‐technical people.
• Proficient in both written and spoken English, at a B2 level or higher.

• Scala and/or functional programming experience.
• Experience transitioning systems from Cloud (GCP/AWS) to bare‐metal or hybrid environments.

• Architectural Advisory – collaborate with the Head of Technology to define the system architecture and provide domain context for connectivity, execution routing, and state management.
• Performance Engineering & PoCs – research and prototype architectural optimizations, building Proofs of Concept for high‐performance components such as evaluating tools like Aeron or optimizing order execution.
• Continuous Performance Analysis – regularly profile the production environment with our Performance Engineer and analyze system behavior post‐factum to identify latency outliers, inefficiencies, and network overheads.
• System Behavior & Risk Logic – ensure technical implementation aligns with trading realities by validating logic for synthetic market generation, handling exchange disconnects, and managing order state during high‐volatility events.
• Provide technical guidance and support throughout the product lifecycle, including early stages of development.
• Technical Mentorship – elevate the domain knowledge of the engineering team through design reviews and feedback, helping generic backend engineers understand constraints of low‐latency trading systems.
• Lead and collaborate with cross‐functional teams, working closely with engineers, analytics, and other groups to navigate varying levels of detail.

• Remote‐first company – you can work from anywhere in the world.
• Flexible working hours – core hours are 11 am–3 pm CET with flexibility outside this window.
• 38 days of paid vacation leave and 14 days of paid sick leave.
• Autonomy to make decisions and explore new ideas in a forward‐thinking team.

• Stage 1 – Screening meeting with Talent Acquisition Partner: basic information about ICEO, the project, the role, and the offer. General questions about your experience (about 30 minutes).
• Stage 2 – Technical Interview with Senior Developer (1 hour).
• Stage 3 – Final Interview with Head of Technology (1 hour).