I build systems that don’t fall over — and I measure them.I build systemsthat don’t fall over —and I measure them.

A RAG demo that answers one question well proves nothing — without a scoring harness, every change is a guess.

• Hybrid FAISS + BM25 retrieval fused by Reciprocal Rank Fusion at k=60
• Evaluation harness written before any tuning, not after
• 289 tests · 87% coverage · live on EC2 behind Docker and Caddy

• Python
• FAISS
• BM25
• FastAPI
• Sentence Transformers

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Installing Redis teaches you Redis — not what it costs to hold a thousand connections, keep a shared map consistent, and survive a SIGKILL.

• Raw TCP sockets, edge-triggered epoll, thread pool at 1,000 connections
• 9,619 ops/sec single connection; 4,831 at 1,000 concurrent
• 10,000 keys recovered in 410 ms after SIGKILL, zero data loss

• C++20
• TCP sockets
• epoll
• POSIX threads
• Write-ahead logging

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Optimisation is slow enough to time out a request, and the market-data API it depends on will eventually fail.

• Optimisation runs offloaded to a Redis job queue — requests return at once
• Dead-letter queue with a retry endpoint for failed jobs
• 163 tests behind an 80% coverage gate enforced in CI

• Python
• FastAPI
• React
• TypeScript
• Redis

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An order is only really paid when the payment processor says so — not when the browser comes back from checkout.

• 15+ REST endpoints with JWT/Bcrypt auth and role-based access control
• Stripe webhooks for real-time order-state consistency
• 3 indexed MongoDB collections behind a component-based admin dashboard

• Node.js
• Express.js
• MongoDB
• React
• Redux

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