Why I Built a C++ MEV Detection Engine That’s 10x Faster Than Python Alternatives

And why performance actually matters in blockchain monitoring

I was watching another MEV opportunity slip away. My Python bot had detected a potential 0.08 ETH arbitrage, but by the time it processed the transaction, the opportunity was gone. This wasn’t the first time, and I knew it wouldn’t be the last.

That’s when I decided to stop fighting Python’s limitations and build MEV Shield — a high-performance MEV detection engine in C++17 that processes 1000+ transactions per second with <15ms latency.

The Performance Problem Nobody Talks About

Most MEV detection tools are built in Python or Node.js. They’re great for prototyping and have fantastic ecosystems, but they struggle with real-time performance:

• Garbage collection pauses create unpredictable latency
• Interpreter overhead slows down processing
• Single-threaded nature of Node.js limits throughput
• Global Interpreter Lock (GIL) in Python prevents true parallelism

When you’re dealing with mempool transactions that appear for milliseconds, these limitations become deal-breakers. Your bot might detect the opportunity, but it will likely miss the execution window.

Why C++ for Blockchain Applications?

I know what you’re thinking: “C++? Isn’t that overkill? Don’t we have modern languages for this?”

Here’s the reality I discovered:

1. Zero GC Pauses = Predictable Performance

// C++ gives us deterministic performance
void process_transaction(const Transaction& tx) noexcept {
auto opportunity = detect_arbitrage(tx); // Always <15ms
if (opportunity.has_value()) {
alert_system.notify(opportunity.value());
}
// No garbage collection, no unexpected pauses
}

Unlike managed languages, C++ doesn’t have garbage collection. This means consistent, predictable latency that doesn’t spike randomly.

2. Lock-Free Data Structures for Maximum Throughput

cpp
moodycamel::ConcurrentQueue<Transaction> queue_;
std::atomic<bool> running_{true};

void process_transactions() {
Transaction tx;
while (running_.load(std::memory_order_acquire)) {
if (queue_.try_dequeue(tx)) {
analyze_mev_opportunity(tx); // Lock-free = no contention
}
}
}

Lock-free queues allow multiple threads to process transactions simultaneously without blocking each other.

3. Memory-Safe Modern C++

Modern C++17 isn’t your grandfather’s C++. We have:

• RAII for automatic resource management
• Smart pointers for memory safety
• Move semantics for zero-copy operations
• Standard library containers that are battle-tested

Real Performance Numbers

During testing, MEV Shield demonstrated:

• 1000+ TPS burst capacity (vs typical 50–100 TPS in Python/Node.js)
• 1–15ms detection latency (vs 50–200ms in interpreted languages)
• 6–7 TPS sustained throughput processing real mempool data
• <100MB memory usage during operation

But the most important metric? Real opportunities caught:

text

[2025-10-27 09:27:38.690] 🚨 HIGH RISK - Profit: 0.0960 ETH | Slippage: 0.3%
[2025-10-27 09:28:26.741] 🚨 HIGH RISK - Profit: 0.1050 ETH | Slippage: 1.9%
[2025-10-27 09:28:38.895] 🚨 HIGH RISK - Profit: 0.1080 ETH | Slippage: 1.1%

These aren’t simulated results. These are actual MEV opportunities that MEV Shield detected and would have captured with proper execution infrastructure.

The Architecture That Makes It Possible

Real WebSocket Monitoring (Not HTTP Polling)

Many “real-time” monitoring tools actually use HTTP polling, which introduces significant latency. MEV Shield uses proper WebSocket connections to multiple RPC providers with automatic failover.

Multi-Threaded Pipeline

text

WebSocket → Parser → Detector → Scorer → Notifier
↓ ↓ ↓ ↓ ↓
Thread 1 Thread 2 Thread 3 Thread 4 Thread 5

Each stage runs in its own thread with lock-free queues between them, preventing any single bottleneck.

Modern C++17 Features

// Zero-copy string views
void parse_transaction(std::string_view tx_data) {
// No allocations, just view into existing memory
auto tx = Transaction::parse(tx_data);
// ... process transaction
}

// RAII for resource management
class WebSocketConnection {
WebSocketClient client_;
public:
WebSocketConnection(const std::string& url)
: client_(url) { // Automatically connects
}
~WebSocketConnection() {
// Automatically cleans up
}
};

Who Is This For?

1. Crypto Exchanges

Protect user withdrawals and deposits from MEV attacks with early warning systems.

2. Trading Firms

Get both protection for your own transactions and detection of profitable opportunities.

3. DeFi Protocols

Warn users about pending MEV risks before they confirm transactions.

4. Developers Learning MEV

Study real MEV patterns with a transparent, open-source implementation.

Open Source and Available Now

I’ve open-sourced MEV Shield under GPLv3 because I believe transparent MEV protection benefits everyone in the ecosystem.

Quick Start:

bash

bash
git clone https://github.com/kemboisre-ctrl/mev-shield.git
cd mev-shield
./scripts/quick_start.sh
# Add your API keys to config/config.yaml
./build/mev_shield

The project includes:

• Python and Node.js client libraries
• REST API and WebSocket interfaces
• Docker support for easy deployment
• Comprehensive documentation

Lessons Learned

1. Performance Matters More Than You Think

In MEV, milliseconds are millions. The difference between 15ms and 150ms latency is the difference between capturing an opportunity and watching it disappear.

2. Modern C++ Is Surprisingly Productive

With features like auto, smart pointers, and the standard library, modern C++ development is much more pleasant than its reputation suggests.

3. The Crypto Ecosystem Needs Performance-First Tools

As blockchain adoption grows, we need tools that can handle the scale. Python and Node.js are great for many use cases, but performance-critical applications deserve performance-optimized foundations.

4. Open Source Builds Trust

In the often-opaque world of MEV, transparency is valuable. Open source allows users to verify what the code is actually doing.

What’s Next?

I’m excited to see how the community builds upon MEV Shield. Some potential directions:

• Multi-chain support beyond Ethereum
• Machine learning for improved detection
• Advanced risk scoring models
• Integration frameworks for popular wallets and exchanges

Try It Yourself

MEV Shield is available at: https://github.com/kemboisre-ctrl/mev-shield

Whether you’re building trading systems, studying MEV patterns, or just curious about high-performance blockchain applications, I’d love your feedback and contributions.

The crypto ecosystem is evolving rapidly, and performance will increasingly become a differentiator. Sometimes, the right tool for the job is the one that’s been reliably solving performance problems for decades.

What are your thoughts on performance in blockchain applications? Have you encountered similar limitations with interpreted languages? I’d love to hear your experiences in the comments below.

Follow me on GitHub for more updates on MEV Shield and other blockchain development projects.

#Blockchain #MEV #CPlusPlus #DeFi #Ethereum #OpenSource #Performance #Trading

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Why I Built a C++ MEV Detection Engine That’s 10x Faster Than Python Alternatives was originally published in Coinmonks on Medium, where people are continuing the conversation by highlighting and responding to this story.