Absolutely — each “box” in your pipeline is not a monolithic thing, it’s a mini-project in itself, containing multiple submodules, each with its own skill set: systems programming, data structures/algorithms (DSA), concurrency, and probability/statistics. I’ll break it down for you as a quant C++ developer roadmap.
📦 1. Market Data Simulator
Purpose: Feed your system with realistic order flow and market events.
Sections / Submodules
-
Order Flow Generator
-
Poisson process → order arrivals
-
Optional: Hawkes process → self-exciting trades
-
Skill: probability + stochastic processes
-
-
Market Event Types
-
Limit orders, market orders, cancels
-
Randomized prices/volumes
-
Skill: statistical modeling, random distributions
-
-
Historical Data Loader
-
Replay real market data (CSV, Parquet)
-
Skill: file I/O, memory-efficient parsing
-
-
Event Queue
-
Thread-safe or lock-free queue
-
Push events to LOB
-
Skill: concurrency, data structures
-
📦 2. Limit Order Book (LOB)
Purpose: Core engine storing all orders and prices.
Sections
-
Data Structures
-
Price → list of orders
-
Bid/Ask trees (O(log n) insert/remove)
-
Skill: STL (map, set) or custom flat structures
-
DSA: balanced trees, linked lists, heap-like queues
-
-
Order Matching (Internal)
-
FIFO price-time priority
-
Partial fills, cancels
-
Skill: algorithms, pointer manipulation
-
-
State Updates
-
Update book after trade
-
Compute mid-price, spread
-
Skill: arithmetic, probability for derived stats
-
-
Performance
-
Cache locality
-
Memory pooling
-
Skill: C++ optimization
-
📦 3. Strategy Engine
Purpose: Decide what prices to quote based on the market.
Sections
-
Fair Price Estimator
-
Mid-price, weighted average, Bayesian updates
-
Skill: probability, statistics
-
-
Bid/Ask Quote Generator
-
Add spread, inventory skew
-
Skill: risk-reward modeling
-
-
Inventory Management (Soft)
-
Prevent overexposure
-
Skill: expected value, variance
-
-
Strategy Interface
-
Communicate with Order Manager
-
Skill: design patterns, modular code
-
📦 4. Order Manager
Purpose: Turn strategy signals into executable orders.
Sections
-
Order Creation
-
Map strategy decisions → LOB orders
-
Skill: object-oriented design
-
-
Order Lifecycle Tracking
-
New, pending, filled, canceled
-
Skill: state machine
-
-
Event Dispatching
-
Send orders to matching engine
-
Skill: concurrency, lock-free queues
-
📦 5. Matching Engine
Purpose: Determine which orders actually execute.
Sections
-
Price-Time Matching
-
FIFO within price levels
-
Skill: data structures, linked lists
-
-
Partial Fills
-
Track remaining quantity
-
Skill: arithmetic, DSA
-
-
Trade Generation
-
Output completed trades to Risk Engine
-
Skill: event-driven architecture
-
📦 6. Risk / PnL Engine
Purpose: Track financial exposure.
Sections
-
Inventory Tracking
-
Long/short positions
-
Skill: cumulative sums, efficient arrays
-
-
PnL Computation
-
Realized/unrealized
-
Skill: probability, expected value
-
-
Risk Metrics
-
VaR, drawdown, Sharpe ratio
-
Skill: statistics, finance math
-
📦 7. Logger / Metrics
Purpose: Record everything and monitor performance.
Sections
-
Trade Logging
-
Orders, fills, timestamps
-
Skill: file I/O, efficient serialization
-
-
Performance Metrics
-
Latency, throughput
-
Skill: system benchmarking
-
-
Alerts & Monitoring
-
Thresholds for positions or PnL
-
Skill: multithreading, concurrency
-
⚡ Key Skill Map Across Modules
| Module | Dev Skills (C++/DSA) | Math / Prob Skills |
|---|---|---|
| Market Data Simulator | Queues, event loops | Poisson/Hawkes, stochastic processes |
| LOB | Trees, linked lists, memory pools | Price stats, spreads |
| Strategy | Interfaces, modular design | Bayesian updates, inventory modeling |
| Order Manager | State machines, event dispatch | Probabilistic order sizing |
| Matching Engine | DSA: priority queues, linked lists | Partial fills, expected execution price |
| Risk Engine | Arrays, accumulators | Variance, expected PnL, VaR |
| Logger / Metrics | File I/O, high-performance logging | Statistics for performance metrics |
🧱 How to Think About This as One Project
-
Each box = mini-project with both engineering + quantitative skills
-
You can build incrementally:
-
Start with LOB (single-threaded)
-
Add matching
-
Add strategy engine
-
Introduce simulator
-
Add risk & PnL
-
Add concurrency
-
Optimize for performance
-
-
Each module has a clear interface → allows future extension
If you want, I can make a full module-to-folder mapping + C++ class design for all 7 boxes, showing exact files, class names, and interconnections, so you can start coding like a real quant dev at Jane Street or Citadel.
Good — this is exactly the level of thinking you need if you’re targeting firms like Jane Street or Citadel Securities.
I’ll treat this like I’m onboarding you as a junior quant dev and giving you a real production-style breakdown.
🧠 1. What You Are Actually Building (Mental Model)
You are NOT just building “a project”.
You are building a mini trading system, composed of:
Market → Order Book → Strategy → Orders → Matching Engine → PnL/Risk
Think in modules, not files.
🏗️ 2. High-Level System Architecture
🔁 Event-Driven Flow
[Market Data Simulator]
↓
[Limit Order Book]
↓
[Strategy Engine]
↓
[Order Manager]
↓
[Matching Engine]
↓
[Risk / PnL Engine]
↓
[Logger / Metrics]
Each box = separate module
📂 3. Production-Grade Folder Structure
Here’s a clean industry-style layout:
market_maker/
│
├── CMakeLists.txt
├── README.md
│
├── include/ # Header files (interfaces)
│ ├── core/
│ │ ├── types.hpp
│ │ ├── order.hpp
│ │ ├── trade.hpp
│ │
│ ├── orderbook/
│ │ ├── order_book.hpp
│ │ ├── price_level.hpp
│ │
│ ├── matching/
│ │ ├── matching_engine.hpp
│ │
│ ├── strategy/
│ │ ├── market_maker.hpp
│ │
│ ├── risk/
│ │ ├── risk_manager.hpp
│ │
│ ├── simulator/
│ │ ├── market_simulator.hpp
│ │
│ ├── utils/
│ │ ├── logger.hpp
│ │ ├── timer.hpp
│ │
│ ├── concurrency/
│ │ ├── lockfree_queue.hpp
│
├── src/ # Implementations
│ ├── orderbook/
│ ├── matching/
│ ├── strategy/
│ ├── risk/
│ ├── simulator/
│ ├── utils/
│ ├── concurrency/
│
├── tests/ # Unit tests
│ ├── test_orderbook.cpp
│ ├── test_matching.cpp
│
├── benchmarks/ # Latency testing
│ ├── bench_orderbook.cpp
│
├── scripts/ # Python (analysis/backtesting)
│ ├── analyze_pnl.py
│
└── data/ # Historical / simulated data
🧩 4. Module Breakdown (What You Must Build)
🔹 1. Core Types (Foundation)
Define:
-
Order
-
Trade
-
Price
-
Quantity
👉 Keep it POD-style structs for performance
🔹 2. Limit Order Book (MOST IMPORTANT)
Responsibilities:
-
Store bids & asks
-
Fast insert/remove/match
Design:
-
Price → linked list of orders (FIFO)
-
Use:
-
std::map(easy) OR -
custom flat structure (fast)
-
🔹 3. Matching Engine
Responsibilities:
-
Match incoming orders
-
Generate trades
Rules:
-
Price-time priority (FIFO)
🔹 4. Market Simulator
Use:
-
Poisson process
Simulate:
-
Order arrivals
-
Cancellations
🔹 5. Strategy Engine (Market Maker)
Core idea:
You quote:
bid = fair_price - spread
ask = fair_price + spread
Use:
-
Expected value
-
Variance
Add:
-
Inventory penalty
🔹 6. Risk Manager
Track:
-
Position
-
Unrealized PnL
-
Realized PnL
🔹 7. Concurrency Layer
-
Lock-free queue between modules
-
Threads:
-
Market data
-
Strategy
-
Execution
-
🔹 8. Backtesting Engine
Replay:
-
Simulated or historical events
Compute:
-
Sharpe ratio
-
Drawdown
🔄 5. Development Workflow (VERY IMPORTANT)
🪜 Phase-by-Phase Plan
✅ Phase 1 (Week 1–2)
-
Core types
-
Simple LOB (single-threaded)
✅ Phase 2
-
Matching engine
✅ Phase 3
-
Market simulator (Poisson)
✅ Phase 4
-
Strategy (basic spread)
✅ Phase 5
-
Risk + PnL
✅ Phase 6
-
Multithreading
✅ Phase 7
-
Optimization
⚡ 6. Sample Code (Order Struct)
struct Order {
uint64_t id;
double price;
uint32_t quantity;
bool is_buy;
uint64_t timestamp;
};
⚡ 7. Performance Principles (CRITICAL)
You must think like this:
❌ Bad:
-
Too many allocations
-
Virtual functions
-
Cache misses
✅ Good:
-
Contiguous memory
-
Object pools
-
Avoid pointer chasing
🎯 8. What Interviewers Care About
At firms like:
-
Jane Street
-
Citadel Securities
They will ask:
-
Why this data structure?
-
What’s your latency?
-
How do you avoid contention?
-
How does your LOB scale?
💥 Final Insight
If you build this properly, you’re showing:
-
Systems engineering (C++)
-
Trading knowledge
-
Probability thinking
-
Performance optimization
👉 That’s exactly the top 1% candidate signal
ALWAYS ASKS ALL THE Design Choices (Interview Style and which to select)
Q: Why intrusive lists over std::list?
A: std::list nodes allocate separately (cache misses + fragmentation). Intrusive reuses Order::next field—zero allocations, perfect locality.
Q: Lock-free vs. fine-grained locks?
A: Ring buffers + RCU for reads; locks only kill tail-latency. 99% paths lock-free hits Citadel/Jane Street benchmarks.
Q: Why PriceMap over red-black tree?
A: LOB prices cluster (10-20 active levels). Bitmap(1<<20) + sparse array = O(1) best bid/ask vs. O(log N).