Elijah Mathai
Technical ledger · 7 entries
Architecture decisions, interaction patterns, and lessons from shipping real product experiments.
SourceTrail is an open-source Hybrid RAG app. Its own benchmark showed vector + keyword fusion ranking worse than vector search alone, so this is the honest retrospective: RRF, a cross-encoder kept as a relevance gate, and the six real failures that shaped the system.
A build log of DocFlow, a document Q&A bot that answers questions about a PDF and shows the exact passages it used. It covers the retrieval pipeline, how I tuned the "I don't know" threshold with an eval set, and the bugs and hosting surprises I hit on the way to production.
Why vector similarity is only one retrieval signal, and how graph context makes grounded answers more dependable.
The architecture behind keeping public media metadata and private tracking progress in sync without confusing ownership.
Why a visually playful grid still needs strict rules for priority, rhythm, and mobile reading order.
A polished component library matters, but the deeper design work lives in states, rules, and transitions.
A fast endpoint can still create a slow product. The useful unit of performance is the user’s complete wait.
