First Principles

A living engineering book for building real products from the math up.

Deep, citation-backed knowledge on e-commerce algorithms, accounting algorithms, agents, LLMs, and the FastAPI / Rust / Go backend path from fast MVP to scalable systems. Maintained as Markdown (for humans) and JSON (for agents), indexed with Trove.

From Velofy, Gurgaon, India.

Why this exists

Most stack advice is tribal. Most algorithm writeups ignore production constraints. This repo treats both as first-class: every major claim points at a public paper or canonical reference, and every backend recipe is framed as MVP first, then scale.

Layout

Path	Purpose
BOOK.md	Reading map and chapter index
book/	Deep prose chapters with citations
catalogs/	Machine-readable JSON: papers, algorithms, stack recipes
research/	Harvest provenance (curl_reap), source notes
.claude/trove/	Project Trove: atomic entries for agents

Topics

1. E-commerce algorithms: retrieval, ranking, CTR, bandits, inventory, pricing
2. Accounting algorithms: double-entry math, ledgers, event sourcing, anomaly signals
3. Agents: ReAct, tools, memory, multi-agent, evaluation, MCP
4. LLMs: transformers, RAG, alignment, fine-tuning, architectures
5. Backend stack: FastAPI best stack, Rust (Tokio/axum), Go (chi/Fiber), polyglot scale

For agents

Start at AGENTS.md. Prefer catalogs/*.json for structured lookup, then open the matching chapter. Project Trove index: .claude/trove/INDEX.md.

# if trove-cli is available from anishfyi/trove
cargo run -p trove-cli --manifest-path ../trove/Cargo.toml -- index
cargo run -p trove-cli --manifest-path ../trove/Cargo.toml -- query "dynamic pricing bandits"

Research method

Public papers and docs were harvested with curl_reap (browser-grade TLS, structured extraction). See research/sources.md and catalogs/papers.json. Junk arXiv ID matches were discarded; only title-verified entries remain.

License

MIT for original Velofy prose and JSON schemas. Cited papers remain under their own licenses (often arXiv perpetual non-exclusive / CC-BY). Do not redistribute PDF binaries from this repo; link to the publisher.