Jobs in London - DeFi Quant Engineer • Central London

Company: Selby Jennings London

Central London

My client, a fast-growing crypto market making start-up, is seeking a DeFi-focused Quant Engineer to help expand and refine their trading and liquidity infrastructure. This is a hands-on role working directly with the founders on the core technology that powers their onchain execution and research stack. Overview The successful candidate will bring strong engineering discipline combined with deep curiosity about how modern onchain markets operate. You will help design and optimise the systems responsible for connecting to AMMs, orderbook venues, and CEXs, while solving complex challenges around latency, finality, and liquidity dynamics across multiple chains. This role is ideal for someone who enjoys dissecting market microstructure, working with high-performance code, and building the technical foundations for next-generation DeFi strategies. Key Responsibilities Build and maintain low-latency connectivity between onchain AMMs, emerging onchain orderbooks, and major CEX venues. Develop high-performance components for pricing, execution, routing, and liquidity management across L1s and various L2 rollups. Optimise ingestion of real-time blockchain data, including mempool flows, state updates, and high-frequency market feeds. Work on the architecture behind cross-chain/rollup execution, accounting for different confirmation and settlement models. Design and prototype mechanisms for advanced liquidity strategies, including dynamic range adjustments, JIT-style liquidity, and MEV-aware execution logic. Contribute to internal research and tooling enabling faster iteration, clean data modelling, and robust risk controls. Required Skills & Experience Advanced degree in a quantitative or technical discipline (maths, physics, CS, engineering, statistics). Strong engineering experience in Rust and Solidity, ideally with multithreaded or asynchronous systems. Prior exposure to low-latency data pipelines, high-throughput trading systems, or performance-critical infrastructure. Understanding of DeFi market mechanics, especially AMM behaviour, liquidity provisioning, or onchain-CEX pricing relationships. Experience building distributed systems interacting with blockchain nodes, RPC layers, or L1/L2 state. Competence with Linux environments, Git-based workflows, containerisation, and modern cloud tooling. Working knowledge of databases, schema design, and efficient querying for real-time applications. Location My client operates primarily from London and has a strong preference for individuals able to work in person or self-relocate. Why This Role? Direct collaboration with the founding team. Ownership of critical systems from day one. Opportunity to influence technical direction at an early stage. Work on cutting-edge DeFi infrastructure with real impact on PnL and trading performance.