Quant Developer and Trading Engineer
Quant developers and trading engineers build the systems that research, price and trade. Learn the main roles, technical skills, interviews and how to prepare.
Behind every modern trading firm is software: systems that receive market data, run strategies, send orders, manage risk, store data and support research. Quant developers and trading engineers build and maintain those systems. Some work close to researchers, turning prototypes into production code and building research platforms. Others focus on low latency infrastructure, where microseconds matter. As trading has become almost entirely electronic, these engineers have become as central to many firms as the traders themselves.
Types of roles#
| Role | Focus | Typical languages |
|---|---|---|
| Quant developer | Production implementation of models, pricing libraries, research tools | Python, C++ |
| Low latency engineer | Market data handlers, order gateways, matching of speed critical paths | C++, Rust, sometimes FPGA languages |
| Trading platform engineer | Order management, risk systems, user interfaces | Java, C#, C++, Python |
| Data engineer | Market data pipelines, storage, research datasets | Python, SQL, Spark |
| Infrastructure and SRE | Servers, networks, deployment, monitoring | Linux, scripting, cloud tools |
| Hardware engineer | FPGAs and network hardware | Verilog, VHDL |
Key technical skills#
| Skill | Lesson |
|---|---|
| Strong programming and data structures | Python for Trading |
| Systems programming and performance | CPU Affinity, NUMA and Cache Optimization and Lock-Free Programming and Ring Buffers |
| Networking | Networking for Traders |
| Market data and protocols | Feed Handlers and Normalization and FIX Protocol |
| Databases and storage | Data Storage, Compression and Caching |
| Testing and reliability | Market Data Replay and Alerts, Error Handling and Reconnection |
| Linux | Linux for Traders |
Understanding the trading domain, such as order types, market structure and risk, makes engineers far more effective. See Order Types Explained and Market Structure Basics.
What the work looks like#
Interviews#
- Coding: algorithms and data structures, often in C++ or Python.
- Systems design: designing an order book, market data system or matching engine. See Matching Engines.
- Low level knowledge: memory, caches, concurrency, networking for latency roles.
- Debugging and code review exercises.
- Some probability and trading questions at many firms.
How it differs from big tech engineering#
| Trading firm engineering | Typical big tech engineering | |
|---|---|---|
| Users | Traders and researchers in the same firm | Millions of external users |
| Feedback | Direct and immediate, often measured in P&L | Product metrics over time |
| Performance focus | Latency and correctness are critical | Scale and availability |
| Cost of bugs | Can be immediate financial losses | Usually user impact and outages |
See Risk Controls and Kill Switches for why correctness matters so much.
Preparing for the role#
- Master a language deeply, especially C++ for low latency or Python for research tooling.
- Build trading related projects: an order book, a backtester, a market data recorder. See Order Book Feeds: Snapshots and Incremental Updates and Building Trading Bots.
- Learn Linux and networking fundamentals.
- Study market structure to understand what the systems do.
- Practise systems design questions.
Frequently asked questions#
What does a quant developer do?#
Builds and maintains the software used for research, pricing, trading and risk at trading firms, often turning researchers' models into production code.
Is C++ required for trading firms?#
For low latency roles, usually yes; many other roles use Python, Java or other languages.
How is a quant developer different from a quant researcher?#
Developers focus on building reliable, fast software systems; researchers focus on finding signals and building models, though the roles overlap.
Next, learn about running portfolios in Portfolio Manager.
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Mentioned in
- Trading DesksThe Trading Industry
- Trading Careers ExplainedThe Trading Industry