Cryptocurrency Exchange

Overview

A spot exchange built around a matching engine designed for latency first — the order book, wallet custody and compliance layer all had to fit around that constraint, not the other way round.

The Problem

The client needed to compete for institutional order flow, which meant execution quality had to hold up under load. Most exchange software is built for feature breadth first and discovers its latency problems after launch, when fixing them means a rewrite.

• An earlier prototype, built on a general-purpose web stack, spiked to multi-second matching latency under simulated load.
• Custody had been designed as an afterthought — a single hot wallet with no separation of risk.
• KYC/AML was a manual review queue that couldn't keep pace with onboarding volume.

How We Solved It

We built the matching engine first, in Rust, sub-millisecond under load, and fit everything else — custody, compliance, the API — around that constraint rather than bolting latency fixes on afterward. Custody got equal priority: hot/warm/cold wallet separation with multi-signature withdrawal approval, because a fast matching engine means nothing if custody is the weak point.

• A price-time priority matching engine, sub-millisecond under load.
• Hot/warm/cold wallet custody with multi-signature withdrawal approval.
• KYC/AML onboarding and transaction monitoring built in, not bolted on.
• A market data feed and REST/WebSocket API for algorithmic traders.

Key Decisions

• Rewrite the matching engine in Rust rather than optimise the prototype. The general-purpose stack's latency ceiling was architectural, not a tuning problem.
• Hot wallet holds only what's needed for same-day withdrawals; everything else moves to cold storage on a schedule, not on demand.
• An independent third-party security audit before any real liquidity, non-negotiable regardless of launch pressure.

The Result

The exchange now handles institutional-grade order flow with sub-millisecond matching, and passed both a security audit and penetration testing before its first dollar of real liquidity touched it.

Matching latency dropped from a multi-second prototype to sub-millisecond in production, and the exchange has run since launch with zero custody incidents.