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For Companies At a Glance
- Tasks: Build and optimise high-performance systems using Rust for live trading infrastructure.
- Company: Onyx Capital Group, a leading technology-driven market-maker in energy derivatives.
- Benefits: Competitive salary, remote work options, and opportunities for personal ownership.
- Why this job: Join a small, impactful team and shape the future of energy trading technology.
- Qualifications: 5-10+ years in software engineering with deep Rust expertise and strong systems programming skills.
- Other info: Dynamic environment with global collaboration and excellent career growth potential.
The predicted salary is between 80000 - 100000 £ per year.
This job is brought to you by Jobs/Redefined, the UK's leading over-50s age inclusive jobs board.
About Onyx Capital Group
Onyx Capital Group is the world's #1 liquidity provider for energy derivatives, trading over $3.2 trillion in notional value annually. Through Onyx Commodities, the Flux Terminal, and our trading division Axis, we dominate the benchmarks that matter - Dated Brent, S2F contracts, and beyond. We are not a bank. We are not a hedge fund. We are a technology-driven market-making powerhouse at the intersection of global energy markets, data, and engineering - and we are growing fast.
Engineering at Onyx
We don’t hire passengers - we hire pilots. Every engineer here takes ownership, pushes back when the design isn’t right, and holds the bar high without being asked. We practise TDD, design for observability from day one, and treat software craftsmanship as a genuine competitive advantage. The team is small, senior, and embedded directly in the trading floor. There are no layers of abstraction between you and the business - your work has immediate, measurable impact from day one.
The Opportunity
We are building our Sri Lanka engineering hub and looking for Senior Rust Software Engineers to be founding members of that team. Working alongside our global engineering organisation, you will take full ownership of complex systems end-to-end - from architecture and design through delivery and into production. Your work will power live trading infrastructure used by some of the world’s most demanding market participants.
Requirements
- 5-10+ years in a software engineering role; track record of delivering production-quality features independently
- Deep Rust expertise - ownership, lifetimes, trait objects, unsafe code, async runtimes, and macro authorship; comfortable working at the boundary of safe and systems-level Rust in production
- Demonstrated experience building low-latency, high-throughput systems in Rust - including performance profiling, benchmarking, and architectural ownership of critical-path services
- Strong systems programming fundamentals - memory layout, concurrency primitives, and lock-free data structures applied in real-world, performance-critical environments
- Test-Driven Development discipline: unit, integration, and E2E tests written as a standard part of the development loop, not an afterthought
- Automation mindset - demonstrated experience identifying and eliminating manual processes through tooling, scripts, and pipelines
- REST API experience - designing, building, and consuming APIs with a clear understanding of authentication, versioning, and error handling
- Source control and CI/CD: GitHub, Azure DevOps, or GitLab; branching strategies, PR workflows, and pipeline contribution
- Experience working in cloud-hosted environments - Azure preferred
- Strong sense of personal ownership - takes a feature from ticket to production without hand-holding, and treats issues in systems they’ve built as their own to resolve
- Comfortable engaging directly with remote end users and business stakeholders to understand requirements, debug issues, and communicate progress clearly - without needing a middleman
- Highly self-motivated with a bias for action - raises problems early, proposes solutions, and follows through to completion
- Strong written and spoken English - clear and confident in both written and verbal communication across synchronous and asynchronous settings
- Experience working with globally distributed teams is strongly welcomed; comfortable collaborating with colleagues in different time zones and cultures
Nice to Have
- FFI experience - calling into C/C++ libraries from Rust or exposing Rust APIs to other languages
- Experience with async Rust runtimes (Tokio / async-std) and designing concurrent, fault-tolerant service architectures
- Experience with agile delivery practices (sprint planning, retrospectives, stand-ups)
- Prior experience in financial services or fintech, or a genuine interest in financial technology and capital markets - not required, but candidates who are curious about the domain tend to thrive here
- Familiarity with message-based architectures (Kafka, NATS, etc.), gRPC / protobuf, or low-level networking (TCP/UDP, DPDK)
- Experience mentoring engineers, leading technical design reviews, or establishing Rust best practices and toolchain standards within a team
What We’re Looking For
You write clean, well-tested code and take pride in it. You don’t wait to be told what needs improving - you spot it, raise it, and fix it. You communicate proactively, work autonomously across time zones, and hold yourself to a standard that makes the people around you better. You want to work on systems that matter and with users who notice when something is even slightly wrong.
Senior Rust Software Engineer in London employer: Onyx Capital Group Limited
Contact Detail:
Onyx Capital Group Limited Recruiting Team
StudySmarter Expert Advice 🤫
We think this is how you could land Senior Rust Software Engineer in London
✨Tip Number 1
Network like a pro! Reach out to folks in the industry, especially those at Onyx Capital Group. A friendly chat can open doors that applications alone can't.
✨Tip Number 2
Show off your skills! If you’ve got a GitHub or personal project showcasing your Rust expertise, make sure to highlight it during interviews. It’s a great way to demonstrate your hands-on experience.
✨Tip Number 3
Prepare for technical challenges! Brush up on your systems programming fundamentals and be ready to discuss your approach to building low-latency systems. They’ll want to see how you think on your feet.
✨Tip Number 4
Don’t forget to apply through our website! It’s the best way to ensure your application gets seen by the right people. Plus, we love seeing candidates who take that extra step!
We think you need these skills to ace Senior Rust Software Engineer in London
Some tips for your application 🫡
Show Off Your Rust Skills: Make sure to highlight your deep Rust expertise in your application. We want to see your experience with ownership, lifetimes, and async runtimes. Don’t just list your skills; give us examples of how you've used them in real-world projects!
Be Clear and Concise: When writing your application, keep it clear and to the point. We appreciate strong written communication, so make sure your thoughts are organised and easy to follow. This is your chance to show us how you communicate, so don’t hold back!
Demonstrate Ownership: We love engineers who take ownership of their work. In your application, share specific instances where you’ve taken a feature from ticket to production. Show us how you handle issues and ensure everything runs smoothly without needing hand-holding.
Apply Through Our Website: We encourage you to apply through our website for a smoother process. It helps us keep track of applications better and ensures you get all the updates directly. Plus, it shows us you're keen on joining our team!
How to prepare for a job interview at Onyx Capital Group Limited
✨Know Your Rust Inside Out
Make sure you brush up on your Rust expertise before the interview. Be ready to discuss ownership, lifetimes, and async runtimes in detail. Prepare examples of how you've tackled complex systems using Rust, especially in low-latency environments.
✨Showcase Your Problem-Solving Skills
During the interview, be prepared to demonstrate your problem-solving abilities. Think of specific instances where you identified issues in systems you built and how you resolved them. This will show your sense of ownership and proactive approach.
✨Communicate Clearly and Confidently
Since you'll be engaging with remote end users and stakeholders, practice articulating your thoughts clearly. Whether it's discussing technical details or project updates, being confident in your communication will set you apart.
✨Emphasise Your Automation Mindset
Highlight your experience in automating processes through tooling and scripts. Discuss any CI/CD practices you've implemented and how they improved efficiency. This aligns perfectly with Onyx Capital Group's focus on technology-driven solutions.