About the job
Role overview
LMAX seeks a C++ and Python Developer to join its Middle-Office Team in London. This group works alongside infrastructure, research, and treasury teams to advance trade reconciliation, back-testing frameworks, and trading monitoring systems. The main focus lies in data engineering and building trading systems from the ground up.
Prior experience in finance or trading is not required for this position.
Team approach
The team operates at the intersection of C++ and Python. C++ powers the infrastructure, while Python supports research tasks like analysis and automation. Bridging these languages is central to the role, supporting integration and collaboration across disciplines.
Performance and optimization
Managing financial data introduces technical challenges, particularly around throughput. The team values software performance but never at the expense of maintainability. Developers work closely with the codebase to understand, optimize, and refine systems.
Testing practices
Comprehensive testing is a core part of the workflow. The team maintains test suites that include unit tests and full end-to-end simulations. Continuous integration runs these tests every 15 minutes, ensuring rapid feedback and no overnight waits for results.
What you will do
- Write clear, well-structured, and thoroughly tested code in C++ and Python
- Develop software solutions that handle high throughput
- Pair program to share knowledge and prevent silos
- Design and implement features to enhance safety, performance, and usability
- Create interface code connecting C++ and Python using pybind
Requirements
- Strong C++ skills, especially with modern C++ on Linux or UNIX
- Python development experience, including Numpy, Pandas, and SQL
- Experience with automated testing for both C++ and Python
- Ability to interpret business requirements and build effective systems
- Skilled at designing simple, well-documented, and maintainable solutions
- Comfortable working independently with minimal supervision
- No finance or trading background needed
Bonus skills
- Experience with test-driven development and testing across multiple system levels
Location
This position is based in London, England, United Kingdom.

