systems project // current WIP

Order Book (Under Construction)

I am building a high-performance electronic limit order book in modern C++ because apparently my idea of a relaxing side project is asking, "what if a queue had opinions about fairness, latency, and the memory hierarchy?"

This is explicitly a current work in progress. It is not done, not polished, and not pretending to be a production exchange. The goal is to understand the infrastructure underneath modern markets: matching orders, preserving price-time priority, and designing data structures that do not make the CPU file a formal complaint.

As it grows, I am planning to add benchmarking, profiling, unit tests, market data feeds, replay tools, and progressively more performance-focused experiments. Less "hot stock tip," more "let me build the tiny engine room where the market plumbing lives."

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[ UNDER CONSTRUCTION ]
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Estimated Completion:

10%

C:\MARKET\LOB>matching_engine.exe

[DONE] boot price-time priority core

[DONE] teach limit orders to stand in line politely

[ACTIVE] wire cancel/modify paths without angering the cache

[QUEUED] benchmark the spicy parts

[QUEUED] add replay tools and market data feeds

[QUEUED] stare at perf traces until enlightenment happens

awaiting next commit

SIM_DEPTHprice-time priority

Bid Size	Bid	Ask	Ask Size
420	101.24	101.25	180
310	101.23	101.26	260
780	101.22	101.27	640
150	101.21	101.28	390
900	101.20	101.29	710

ILLUSTRATIVE DEMORUN MATCHING CYCLE

The resting book holds queued buy bids and sell asks. The demo introduces a buy priced high enough to trade with the cheapest asks.

RESTING BOOKBID 12 @ 100.95BID 15 @ 100.90ASK 8 @ 101.05ASK 6 @ 101.10ASK 10 @ 101.20

ENGINE

Matching logic first

The core goal is an electronic limit order book that processes limit, market, cancel, and modify orders while maintaining price-time priority.

SYSTEMS

Latency-minded C++

This is less get-rich-quick and more why-is-this-pointer-chasing-making-my-CPU-sad: memory layout, cache behavior, and low-latency design are the fun bits.

TOOLING

Benchmarks incoming

The project will grow into unit tests, profiling, benchmarks, replay tooling, and performance experiments that make the engine easier to trust.

WHY

Market plumbing is cool

I am not building a trading strategy. I am building the infrastructure side quest: the machinery that lets modern markets exist without everyone yelling numbers across a room.