HFT Core Engineer | 42.com

About 42.com

42.com is a proprietary hedge fund where technology is the core advantage. The company is rethinking financial market forecasting using modern systems, new hardware paradigms, and frontier AI. The fund operates tightly with an internal AI Research Lab — together they design and own the full stack from research ideas to production trading systems.

The engineering culture is more like a classic IT/research company than a traditional trading firm: frequent group work, cross-functional projects, and open communication.

42.com is building the core trading system from scratch — a first-principles design, not an iteration on legacy infrastructure. They are looking for HFT Core Engineers to own the central execution engine, internal data model, and critical runtime components.

What you are expected to do

• Design and implement the core trading engine: event loop, scheduling, and execution flow

• Define and build internal data models for order books, trades, positions, and state transitions

• Develop execution systems: order lifecycle management, smart order routing, risk checks, and position tracking

• Design and implement real-time risk systems: pre-trade checks, exposure limits, kill-switches, and capital allocation constraints across strategies

• Build treasury and funds routing logic: capital distribution across venues, internal netting, collateral management, and efficient movement of funds between accounts

• Ensure consistency and correctness of the state under high load and partial failures

• Optimize critical paths for latency and throughput (CPU cache, memory layout, branch prediction)

• Collaborate with connectors and research teams to ensure clean interfaces and minimal overhead integration

• Build the system with a phased market scope: start with crypto markets (spot, perps), then extend to traditional markets (equities, futures, options) with unified abstractions

What you need to succeed

• Experience building low-latency systems (HFT, real-time systems, or similar)

• Strong systems programming skills in C++

• Deep understanding of concurrency, memory models, and performance optimization

• Experience designing complex systems from scratch with clear abstractions and minimal overhead

• Understanding of trading system components: order lifecycle, execution logic, and risk controls

• Familiarity with capital management, risk systems, or treasury workflows in trading environments

• Ability to reason about correctness under concurrency and failure

• Experience with profiling and performance tuning at the CPU level

• Proactive and initiative-driven

• Comfortable working closely with a team in a collaborative engineering environment

• English Proficiency

What you get

• Greenfield opportunity: Build the entire core trading system from scratch within a tech-first hedge fund backed by a strong AI Research Lab. First-principles design, no legacy.

• Freedom and ownership: Own the central execution engine, data model, and critical runtime components. Full ownership of the platform from architecture to production.

• Culture: Collaborative, engineering-oriented environment: frequent group work, cross-functional projects, and open communication.