Swapnanil Saha
I build Vectr, semantic search and working memory for AI coding agents, and write long-form engineering deep dives. The research underneath it is on arXiv.
Deep dives.
Measured, not summarized.
Long-form engineering essays on retrieval, agent memory, and context engineering — built on instrumented runs and honest ledgers, with every number traceable to an artifact.
I Deleted Every Ranking Heuristic From My Code Search Engine
Embedding Dilution: Why Semantic Code Search Misses the Answer
What Actually Survives /compact in Claude Code
Semantic search.
Working memory.
Six tools.
Shipped.
Six production-grade tools — each solving a real enterprise problem with LLM APIs. Built independently, in public, to the same standard I'd apply to internal tooling at scale. Each ships with Docker, a REST API, input validation, and a full landing page.
vectr
dpdp-copilot
rag-readiness
llm-eval-suite
ai-use-case-scoper
meeting-to-action
What I'm
building.
Where the instinct
comes from.
I build Vectr, write long-form engineering deep dives, and publish the research underneath them. Beneath all of it sit nine years in the engine room of real-time digital advertising, building infrastructure that decides in milliseconds which ad a user sees: a custom Redis module that cut filtering latency 5×, first-price and second-price auction engines, real-time budget pacing on Cassandra across billions of daily requests.
Ad-tech has an unusually short feedback loop. Every latency improvement carries a win-rate implication, every auction change shows up in revenue by the same afternoon. That is where the habit of refusing a claim without an instrumented run behind it comes from, and it is the standard everything published here is held to.
Let's
talk.
Open to conversations about agentic AI, context engineering, retrieval, and the harness problems that surface when a model has to hold state across long-running work. Early results, half-formed hypotheses, and work that has not been written up yet are the most interesting kind of mail to get, and the topic does not have to be one covered here.
Corrections carry the same weight as agreement. A number on this site that does not reproduce is worth an email.