Senior Java Engineer (Low Latency / Trading Systems) - £950-1150/Day Outside IR35 Contract
Posted Today by Owen Thomas | Pending B Corp™
£150 Per hour
Outside
Hybrid
London Area, United Kingdom
Summary: The Senior Java Engineer role focuses on designing and optimizing low latency Java systems for a high-performance trading and data platform. The position requires hands-on experience in building real-time, high-throughput systems that process live market data and support high-frequency decision-making. Candidates will work in a performance-critical environment where engineering quality directly impacts production systems. This contract role is hybrid, requiring 2-3 days per week in the office in London.
Key Responsibilities:
- Building and optimizing low latency, high-throughput Java systems for real-time data and trading workflows
- Designing components within a distributed, event-driven architecture handling large-scale streaming data
- Developing pricing, risk, and data processing systems used in live environments
- Applying advanced techniques in concurrency, GC tuning, memory management, and performance optimization
- Improving system performance across latency, throughput, and reliability constraints
- Contributing to architecture across data pipelines, streaming systems, and backend services
- Supporting and enhancing production systems in time-critical scenarios
Key Skills:
- Strong experience building low latency systems in Java (ideally Java 17/21+)
- Proven background in high-performance, data-intensive or trading systems
- Deep understanding of JVM internals, concurrency, and performance tuning
- Experience designing and building distributed systems at scale
- Strong experience with real-time data processing and event-driven architectures (e.g. Kafka or similar)
- Ability to reason about latency vs throughput vs consistency trade-offs
- Comfortable working in production-critical environments with real-time constraints
- Highly desirable: Experience with Aeron, Chronicle or LMAX disruptor
- Experience in electronic trading, pricing, or risk systems
- Knowledge of FIX protocol, order routing, or market connectivity
- Exposure to high-frequency or ultra-low latency environments
- Experience working closely with Quants or front-office stakeholders
- Background across asset classes such as FX, Equities, Commodities or Derivatives
Salary (Rate): £150.00/hr
City: London
Country: United Kingdom
Working Arrangements: hybrid
IR35 Status: outside IR35
Seniority Level: undetermined
Industry: IT
Senior Java Engineer (Low Latency / Trading Systems) - £950-1150/Day Outside IR35 Contract London (Hybrid) | High-Performance, Real-Time Platform
We’re working with a high-performing engineering team building real-time, high-throughput systems at the core of a complex trading and data platform. This is a hands-on contract role focused on designing and optimising low latency Java systems that process live market data, power pricing and risk engines, and support high-frequency decision-making. You’ll be operating in an environment where performance is critical, latency is measurable, and engineering quality directly impacts production systems.
What you’ll be working on
- Building and optimising low latency, high-throughput Java systems for real-time data and trading workflows
- Designing components within a distributed, event-driven architecture handling large-scale streaming data
- Developing pricing, risk, and data processing systems used in live environments
- Applying advanced techniques in concurrency, GC tuning, memory management, and performance optimisation
- Improving system performance across latency, throughput, and reliability constraints
- Contributing to architecture across data pipelines, streaming systems, and backend services
- Supporting and enhancing production systems in time-critical scenarios
Core requirements
- Strong experience building low latency systems in Java (ideally Java 17/21+)
- Proven background in high-performance, data-intensive or trading systems
- Deep understanding of JVM internals, concurrency, and performance tuning
- Experience designing and building distributed systems at scale
- Strong experience with real-time data processing and event-driven architectures (e.g. Kafka or similar)
- Ability to reason about latency vs throughput vs consistency trade-offs
- Comfortable working in production-critical environments with real-time constraints
Highly desirable
- Experience with Aeron, Chronicle or LMAX disruptor
- Experience in electronic trading, pricing, or risk systems
- Knowledge of FIX protocol, order routing, or market connectivity
- Exposure to high-frequency or ultra-low latency environments
- Experience working closely with Quants or front-office stakeholders
- Background across asset classes such as FX, Equities, Commodities or Derivatives
Tech environment (indicative)
- Java (core), JVM ecosystem
- Distributed systems, microservices, event-driven architecture
- Streaming technologies (Kafka or equivalent)
- Real-time data pipelines
- Cloud infrastructure (AWS / GCP)
- Observability, performance monitoring, and diagnostics tooling
The environment
- Engineering-led, performance-focused culture
- Fast-paced environment with real production impact
- Close collaboration with quantitative and trading teams
- Hybrid working model (London-based) - 2-3 days per week required in office
Why this contract?
This is a role for engineers who care about how systems behave under pressure. You’ll be working on platforms where:
- Milliseconds (and often microseconds) matter
- System performance is constantly measured and improved
- Your work directly impacts real-time decision making
If you’ve built low latency systems and want to work closer to real trading environments , this is a high-impact contract opportunity.