Java Software Engineer

Saragossa; Greater London; On-site; GBP 120,000 - 180,000; Full time

Job summary

Saragossa is seeking a Senior Java Developer (Low-latency) to join the Energy Trading Tech team. You will help build the core trading platform, focusing on venue connectivity, messaging, sequencing, and recovery mechanisms to enable real-time digital trading.

You will work on distributed, high-throughput systems in Linux environments, with emphasis on debugging and performance optimization. This contract role outside IR35 offers exposure to cutting-edge trading infrastructure and cloud tooling.

Qualifications

• Strong Java development with low-latency experience.
• Experience building distributed, event-driven or high-throughput systems.
• Strong understanding of Linux-based environments.
• Experience with concurrent and multi-threaded programming.

Responsibilities

• Develop core components of the trading stack and ensure low-latency performance.
• Connect venue and exchange systems and ensure reliable messaging and sequencing.
• Implement replay, recovery mechanisms and observability tooling.
• Support cloud deployment, monitoring, and operational excellence.

Skills

Java

Low-latency

Distributed systems

Linux

Concurrency

Messaging

High-throughput

Debugging

Sequencer architecture

Data-intensive

Job description

Senior Java Developer (Low-latency) - Energy Trading - Contract - Outside IR35

An energy trading company are looking for an experienced software engineer to join their Trading Technology team and help build the core platform that powers their trading business.

This role focuses on the foundational components of the trading stack, including:

• Venue and exchange connectivity
• Messaging and sequencing systems
• Replay and recovery mechanisms
• Cloud deployment and operational tooling
• Platform observability and monitoring

They are setting up function to enable digital trading across the business. This is an exciting initiative to dream big and augment their trading initiatives across the board spanning data, real-time infrastructure, quant trading, algorithmic trading and electronic risk oversight.

They already have a strong set of business deliverables across real-time power, quant trading and the automation of their gas trading. More will follow.

You will have:

• Strong Java development skills along with experience with low- latency engineering.
• Experience building distributed, event-driven or high-throughput systems
• Strong understanding of Linux-based environments
• Experience with concurrent and multi-threaded programming
• Experience working with messaging, networking or data-intensive applications
• Strong problem-solving and debugging skills.
• An absolute bonus would be if you have worked on sequencer architecture.