# Backend Developer (C++/C#) - High-performance trading systems > Koton · Brno, Czechia (Hybrid) · Contract · Posted 2026-10-07 **Salary:** EUR 60,000–110,000 **Workplace:** hybrid **Department:** Engineering ## Description _We trade the world's most volatile markets and make them more efficient. _**Koton is a boutique, proprietary trading firm and a top-tier market maker** on the world's largest crypto exchange. Our core is high-frequency market making, where the speed and cost-efficiency of execution decide the outcome. We build software that trades real capital in live crypto markets. Every microsecond, every allocation and every design decision has a measurable impact on PnL. **Engineering isn't supporting the business here, it is the business.** When the system performs well, we make more money. When it doesn't, we lose our own. That creates a very different engineering environment from most software companies. Most of the codebase is .NET today. Parts of the performance-critical core are moving to C++, while the business continues to evolve with new trading features, infrastructure and exchange integrations. You'll work across both worlds — improving today's production systems while helping shape tomorrow's architecture. You'll own meaningful parts of the system from day one. **What you'll do** **Design and build the high-performance services behind our trading systems** while improving existing production software and gradually moving performance-critical components from C# to C++. **Work on performance where it genuinely matters** — allocations, latency, throughput, memory layout and cache behaviour. Not micro-optimisation for its own sake: a bad fill and a missed opportunity are the units we measure in. **Integrate with exchanges.** HTTP, WebSockets and FIX, including binary protocols. Real-time market data, order flow, account and user data streams. Exchange documentation lies, sequences go out of order and streams drop — the system either stays consistent or fails fast and loudly. **Chase the hard class of bugs.** Race conditions, lifetime and use-after-free issues, memory corruption and the things that only appear under production load. This is a real part of the job, not a footnote. **Run what you build.** Deploy and operate on Linux (AWS), keep it observable with structured logging and metrics, and handle incidents. Crypto markets run 24/7 and deploys go into a live market with a real position. We don't have an ops team to clean up behind you, which is exactly why nobody here ships something they don't understand. **Work directly with researchers and traders** on implementing new strategies and improving the system. You get a problem and context, not a written-up ticket. **What ownership actually means here** We say ownership because it's the main thing we're offering. - You get **problems, not specifications.** We expect engineering judgement rather than following predefined designs. - You own **systems, not tasks.** Within a few months you'll be the person who understands a part of the core better than anyone else. - You build it, deploy it and support it. There are no product managers translating requirements or separate ops teams taking over after release. - Your results are visible immediately. Latency, reliability and PnL settle arguments much faster than presentations ever could. ## Requirements - Strong C++ with demonstrable performance-sensitive work. You're comfortable reasoning about memory layout, ownership and lifetimes, and what the compiler actually emits. - Strong C#, particularly the performance-sensitive side. GC behaviour, allocation-free code, async/await, BenchmarkDotNet or dotTrace. Most of the system still lives here, and understanding it is essential before improving or migrating it. - A solid grasp of concurrency — multithreading, thread safety, memory ordering, ideally lock-free approaches, and a sense of when lock-free is the right answer and when it's a trap. - The ability to profile and tune, not guess. perf, sanitizers, benchmarking harnesses. When someone says "this will be faster", we ask how they measured it. - Confidence on Linux. - End-to-end ownership. You take a problem, decide how to solve it, build it, ship it and keep it running. - Diligence and discretion. You'll be working close to trading logic and real capital. - Willingness to be occasionally on call when an exceptional incident needs a fast response. **Bonus points** - Python for tooling, data work and scripting around the systems, and for working with researchers. - Understanding of trading mechanics — order books, market data, execution. - Networking and latency tuning — sockets, TCP behaviour, protocol-level optimisation. - PostgreSQL or TimescaleDB, and database performance tuning. - AWS. **You don't need to know trading. Most of us didn't. What you do need is curiosity. You can't write good code for a system whose commercial purpose you don't understand.** ## Benefits - **Paid time off** to actually switch off - **Fully catered office**: all-day snacks, daily lunch, coffee and drinks on us - **Work-from-home flexibility** - **Training and development** to keep sharpening your edge - **Performance bonuses** tied to results - **Relocation support** for candidates moving to Czechia - **Pick your own hardware**, top-spec kit, no IT-catalogue limits **Annual salary:** This depends on your experience, the level of ownership you take on, and other factors. We believe in paying fairly, with a base salary typically ranging from 60,000 to 110,000 EUR per year, and we're always open to a conversation. We like to work with smart people and want them to feel appreciated and to enjoy the work they do here. ## Apply [Apply at Koton](https://apply.workable.com/koton-trading/j/B0228F30A9/apply) --- Powered by [Workable](https://www.workable.com)