Java Developer – Algo Development Technology (Equities)

Millennium; Greater London; On-site; GBP 80,000 - 100,000; Full time

Job summary

Millennium is seeking an experienced developer to enhance algorithmic trading systems. With over 7 years in equities execution systems, you will work on building and evolving those systems, utilizing your expert-level Java skills and understanding of market microstructure.

This role requires collaboration with technologists and the ability to implement innovative solutions while navigating market constraints. At Millennium, you'll be part of a team that values initiative and insight within a collaborative environment.

Qualifications

• 7+ years of experience with equities execution systems.
• Expert-level Java skills and understanding of low-latency, high-throughput systems.
• Strong understanding of market microstructure and regulatory requirements.

Responsibilities

• Develop high-quality features for algorithmic trading systems.
• Enhance execution platforms in a fast-paced environment.
• Translate business requirements into effective technical solutions.

Skills

Equities execution systems

Execution algorithms (VWAP, TWAP, etc.)

Java programming

Low-latency systems

Distributed architectures

Tools

Kafka

Solace

Job description

About Millennium

Millennium is a global, diversified alternative investment firm, founded in 1989. Defined by evolution, innovation and focus, Millennium’s mission is to deliver results for our investors. Our people are empowered with both independence and support: the autonomy to pursue ideas with conviction and the backing of a global network committed to collaboration, disciplined risk management and continuous learning. With opportunities to deepen expertise and accelerate development, talent at Millennium is equipped to adapt, evolve and build lasting impact over time. Discover how transformative growth accelerates impact.

Meet the Team

Core to the health and growth of Millennium’s business, the Information Technology organization develops flexible, scalable technology and advanced proprietary systems that support the firm’s active, multi‑manager model. Within this organization, the Equities Tech Algorithmic Development team builds and enhances execution technology that supports Portfolio Managers and trading partners across the platform, with a focus on high‑performance, real‑time trading systems and execution capabilities.

What You’ll Do

• Partner closely with technologists, Execution Services, and Equity Finance teams to enhance the firm’s execution offering for Portfolio Managers
• Build and evolve real‑time algorithmic trading systems and execution platforms in a fast‑paced environment
• Develop high‑quality new features and enhance functionality on a mission‑critical platform
• Design and upgrade software to meet performance, scalability, and quality expectations
• Translate business requirements and market constraints across developed and emerging markets into effective technical solutions
• Stay current on relevant technologies, tools, technical libraries, computing environments, and academic research
• Support data analysis and provide L3 troubleshooting for issues affecting critical trading infrastructure

What You Bring

• 7+ years of experience with equities execution systems
• Experience developing execution algorithms such as VWAP, TWAP, Inline, and Pairs
• Experience working on matching engines and dark pools
• Experience implementing automated testing strategies for algorithms, including simulation, backtesting, regression suites, and replay frameworks
• Deep understanding of market microstructure, pre‑trade risk checks, limit frameworks, and regulatory requirements, and how they affect execution algorithm performance
• Expert‑level Java skills, with extensive experience building low‑latency, GC‑aware, high‑throughput distributed systems
• Strong understanding of distributed, event‑driven architectures and messaging technologies such as Kafka, Solace, or similar tools
• Experience working with or building algo container frameworks; experience using AI tools to improve developer productivity is a plus