Software Developer (Java)

LMAX Group; Greater London; Hybrid; GBP 85,000 - 120,000; Full time

Benefits offered by this job

25 days holiday

Bonus

Pension contribution

Private medical, dental, and vision

Life assurance

Critical illness cover

Wellness program with ClassPass

Five volunteering days

Giving as You Earn

Learning and development programs

Electric Vehicle Scheme

Cycle to Work Scheme

Season Ticket Loan

Job summary

LMAX Group is a high-performance financial exchange known for ultra-low latency Java systems. You will work across the stack—from backend core Java to frontend JavaScript—on greenfield cloud-based solutions and a cooperative, knowledge‑sharing culture.

Join a team that values fast feedback, pair programming, and ongoing learning through internal tech talks, conferences, and dedicated personal development time.

Qualifications

• Be passionate about software development.
• Work in a dynamic environment enabled by fast feedback; the heart of our ethos
• Pair programming in small teams of developers and testers (who also write code)
• Share knowledge and learn from like-minded peers
• Work across a variety of teams covering a wide range of technologies
• Write performant, reliable, and well tested code - shipping only when it's ready

Responsibilities

• Work across the stack to solve a problem in a high-performance Java environment
• Collaborate with backend, frontend, data analytics and testing teams
• Contribute to deployment and operating in Kubernetes and Nomad
• Participate in internal tech talks and knowledge sharing events

Job description

LMAX is renowned for its high-performance, ultra-low latency (we measure in microseconds) exchange written in core Java. We constantly push technology further than most, especially in our greenfield projects, driving the financial industry in new directions.

Developers are encouraged to constantly develop and learn new skills. Pair programming supports continual growth of knowledge and sharing of expertise, alongside regular team rotations ensuring everyone gains first-hand knowledge on all areas of our codebase. Friday afternoons are set aside as personal development time where you can explore a different coding language, research bleeding edge technologies, or play around with one of our environments. There is also regularly scheduled time to improve developer experience and reduce technical debt - directed by developers.

Our continuous integration and testing culture allows us to have confidence in our builds and develop quickly. We have over 30,000 acceptance tests running every 25 mins in our CI, alongside extensive test suites (performance, compatibility, migration, resilience). Continuous Delivery was pioneered at LMAX one of the authors worked here while writing the book). Due to pair programming and testing we don't do pull requests, we push directly to our monorepo with a "revert first, ask questions later" attitude.

If you want to work with great developer practices like fast feedback across all aspects of your work, a cooperative culture, and only shipping things when they're ready, while being at the heart of a thriving exchange with opportunities to learn about the finance industry, then LMAX is for you!

What you should expect:

• Collaborative office environment with constant pairing and plenty of social activities
• Work across the stack to solve a problem - You might be working with a performance critical component, integrating a new blockchain, or designing a greenfield cloud based system
• Regular opportunities to learn and develop yourself with internal tech talks, ability to travel to conferences, and dedicated time for your personal development

What you'll be working with:

• Backend: Distributed, event-driven core Java (90% of the code-base), MySQL, Kafka
• Frontend: Javascript, Vue.js
• Deployment: Kubernetes, Nomad
• Data analytics: Python & Jupyter notebooks, Parquet, Docker
• Testing: JUnit, JMH, JCStress, Jenkins, Selenium, many in-house tools..
• OS: Linux (Fedora for development, Rocky in production)

The LMAX way is to use the right tool for the job so this is just a flavour of what you'll be working with, and isn't a list of requirements!

Requirements

• Be passionate about software development. Bad code offends you!
• Work in a dynamic environment enabled by fast feedback; the heart of our ethos
• Pair programming in small teams of developers and testers (who also write code)
• Share knowledge and learn from like-minded peers
• Work across a variety of teams covering a wide range of technologies
• Write performant, reliable, and well tested code - shipping only when it's ready

Benefits

• 25 days of holiday
• Bonus
• Pension contribution
• Private medical, dental, and vision coverage
• Life assurance
• Critical illness cover
• Wellness contribution program with access to ClassPass
• Plumm Platform
• Five volunteering days
• Give as You Earn initiative
• Learning and development programs
• Electric Vehicle Scheme
• Cycle to Work Scheme
• Season Ticket Loan