Java Low Latency Connectivity Developer

London | 4 Days Office, Victoria | Crytpo Exchange Connectivity / FIX

A specialist electronic trading firm is seeking a Java Low Latency Connectivity Developer to join a highly technical, performance-driven engineering team.

The business operates automated trading strategies across both traditional financial markets and crypto venues. Technology is central to performance, and connectivity to exchanges is a core competitive edge.

This is a hands-on role within a small, experienced team where engineers work directly on systems that impact live trading outcomes.

The Role

You will be responsible for designing, building and optimising exchange connectivity across multiple venues, with a strong focus on crypto markets.

Key responsibilities include:

* Developing ultra-low latency Java components

* Managing FIX protocol sessions and order flow

* Integrating and optimising crypto exchange APIs using REST and WebSocket

* Handling real-time JSON market data feeds

* Improving performance and reducing latency across exchange connections

* Supporting and enhancing live trading systems

Each exchange has its own architecture, API behaviour and performance characteristics. You will play a key role in ensuring reliable, high-performance connectivity across them.

What We Are Looking For

* Strong core Java expertise

* Experience in low latency or performance-critical systems

* Solid understanding of FIX protocol (session and application layers)

* Direct experience connecting to trading venues or exchanges

* Hands-on experience integrating with crypto exchanges

* Strong understanding of REST and WebSocket APIs in real-time environments

* Experience working in Linux-based production systems

Exposure to high-performance libraries such as Aeron, Agrona, SBE or Artio is advantageous.

The Environment

* Small, collaborative engineering team

* Flat structure with real ownership

* Office-based in Victoria, London (4 days per week)

* 24/7 automated trading systems

* Occasional out-of-hours support rotation

This role is well suited to engineers who enjoy working close to the market, solving hard performance problems, and taking responsibility for exchange connectivity in a fast-moving environment