Saṃhitā — Notes Field notes by Yesudeep Jose Mangalapilly. https://yesudeep.com/blog/ 2026-07-03T00:00:00+00:00 Yesudeep Jose Mangalapilly Can I Use This Library? https://yesudeep.com/blog/can-i-use-this-library/ 2026-07-03T00:00:00+00:00 2026-07-03T00:00:00+00:00 A strict CSP quietly turns every dependency into a security decision. Here is the tree I walk to make it — per library, and across a whole app. The Header That Can't Be Cached https://yesudeep.com/blog/the-header-that-cant-be-cached/ 2026-07-03T00:00:00+00:00 2026-07-03T00:00:00+00:00 Cache-Control from first principles — and why a page carrying a CSP nonce must be told never to be stored, not merely "don't cache." Trust No Script https://yesudeep.com/blog/trust-no-script/ 2026-07-03T00:00:00+00:00 2026-07-03T00:00:00+00:00 Why a strict Content Security Policy is one of the hardest headers to deploy — and how to read a real one with Google's CSP Evaluator. The URL Is the Hash https://yesudeep.com/blog/the-url-is-the-hash/ 2026-06-30T00:00:00+00:00 2026-06-30T00:00:00+00:00 Content-addressing on the wire — how the web quietly became a content-addressed store, where fingerprinted URLs and Subresource Integrity are real Merkle edges and the cache that looks most like one isn't. You Don't Want Separate Repos https://yesudeep.com/blog/you-dont-want-separate-repos/ 2026-06-29T00:00:00+00:00 2026-06-29T00:00:00+00:00 A repository is a database; splitting a subproject out trades a content hash for a version string — and there's only one case where that trade is actually forced. A Language That Can't Loop Forever https://yesudeep.com/blog/a-language-that-cant-loop-forever/ 2026-06-26T00:00:00+00:00 2026-06-26T00:00:00+00:00 Bazel's Starlark forbids unbounded loops and recursion on purpose, and gets analyzability, caching, and parallelism in return. Buck2 quietly allows recursion back — and the split shows which restriction is load-bearing. A Little Uncertainty Buys a Lot of Space https://yesudeep.com/blog/a-little-uncertainty-buys-a-lot-of-space/ 2026-06-26T00:00:00+00:00 2026-06-26T00:00:00+00:00 Bloom filters trade a small chance of being wrong for an enormous saving in memory — a bargain storage engines take and build systems, so far, refuse. node_modules Is the Heaviest Object in the Universe https://yesudeep.com/blog/node-modules-is-the-heaviest-object-in-the-universe/ 2026-06-26T00:00:00+00:00 2026-06-26T00:00:00+00:00 The same "the hash is the identity" idea that powers a build cache also explains why pnpm stores on disk what npm copies a hundred times over. The Build That Restarts Itself https://yesudeep.com/blog/the-build-that-restarts-itself/ 2026-06-26T00:00:00+00:00 2026-06-26T00:00:00+00:00 Inside Skyframe, Bazel's incremental engine — and the strange trick at its heart. The Grain of the Machine https://yesudeep.com/blog/the-grain-of-the-machine/ 2026-06-26T00:00:00+00:00 2026-06-26T00:00:00+00:00 A processor isn't a featureless calculator — it has a shape: words, cache lines, vector lanes. Code that moves with that grain runs many times faster than code that fights it, on the very same data. Here's the shape, and a measured case where the same arithmetic runs 22× slower against it. The Hash Is the Identity https://yesudeep.com/blog/the-hash-is-the-identity/ 2026-06-26T00:00:00+00:00 2026-06-26T00:00:00+00:00 Content-addressing in the build cache — content-addressed storage and Merkle trees turn a build cache into a shared resource, so your build is proportional to anyone's change. The Widest Box Is the Bug https://yesudeep.com/blog/the-widest-box-is-the-bug/ 2026-06-26T00:00:00+00:00 2026-06-26T00:00:00+00:00 A flamegraph turns thousands of stack samples into one picture where the slow code is, almost literally, the biggest thing on the screen. There Are No Phases https://yesudeep.com/blog/there-are-no-phases/ 2026-06-26T00:00:00+00:00 2026-06-26T00:00:00+00:00 Buck2's DICE engine collapses load, analysis, and execution into a single graph — and the decision to rebuild rather than adopt. Utils Is Where Modularity Goes to Die https://yesudeep.com/blog/utils-is-where-modularity-goes-to-die/ 2026-06-26T00:00:00+00:00 2026-06-26T00:00:00+00:00 Module boundaries should follow the dependency graph, not your folder intuitions — and "optimal" can be defined precisely. With the Grain https://yesudeep.com/blog/with-the-grain/ 2026-06-26T00:00:00+00:00 2026-06-26T00:00:00+00:00 The original turned a big integer into bytes one byte at a time, fighting the machine. The rewrite went with its grain — whole machine words, packed in C. That structural choice is why it's still ~15× faster fifteen years on, even as CPython sped up underneath it. The Build Is Proportional to the Change https://yesudeep.com/blog/build-is-proportional-to-change/ 2026-06-25T00:00:00+00:00 2026-06-25T00:00:00+00:00 What every build system is really doing — and the one decision that separates the ones that scale. Scaffolding a Typographic Portfolio Site https://yesudeep.com/blog/scaffolding-a-typographic-portfolio-site/ 2026-05-26T00:00:00+00:00 2026-05-26T00:00:00+00:00 The design philosophy behind this site — why it's built from durable tools and a purposeful type system instead of a framework, and why every choice is aimed at lasting. The Patch Bram Applied https://yesudeep.com/blog/the-patch-bram-applied/ 2026-04-09T00:00:00+00:00 2026-04-09T00:00:00+00:00 A small contribution to Vim, the man who took it, and the editor I still open every morning. Designing an API That Outlives You https://yesudeep.com/blog/designing-an-api-that-outlives-you/ 2026-02-12T00:00:00+00:00 2026-02-12T00:00:00+00:00 I wrote watchdog in 2010. Fifteen years and three maintainers later it still ships the same public API I designed — here's what made it last. Everything Is an Action https://yesudeep.com/blog/everything-is-an-action/ 2025-01-20T00:00:00+00:00 2025-01-20T00:00:00+00:00 The architecture of Firebase Genkit rests on one primitive — a self-describing, observable, callable function — and the whole SDK is layers of specializations of it. Reading a Codebase https://yesudeep.com/blog/reading-a-codebase/ 2025-01-15T00:00:00+00:00 2025-01-15T00:00:00+00:00 A method for taking real software apart at the source level — find the one type everything hangs from, extract the algebra, and learn what the designers refused to allow. I like the way Aquamacs looks. I don’t use it because it feels different https://yesudeep.com/blog/aquamacs-vs-stock-emacs/ 2009-12-14T00:00:00+00:00 2009-12-14T00:00:00+00:00 Why I keep stock GNU Emacs over Aquamacs — one consistent editor across every OS. Even faster String.prototype.trim() implementation in JavaScript https://yesudeep.com/blog/even-faster-string-trim/ 2009-07-31T00:00:00+00:00 2009-07-31T00:00:00+00:00 A faster, non-regex String.prototype.trim() — later adopted into early JS frameworks. Making the browser download scripts in parallel https://yesudeep.com/blog/parallel-script-loading/ 2009-07-29T00:00:00+00:00 2009-07-29T00:00:00+00:00 Loading multiple scripts concurrently instead of the browser’s serial default. memcache.js for Google App Engine application front-ends? https://yesudeep.com/blog/memcache-js-for-app-engine/ 2009-07-25T00:00:00+00:00 2009-07-25T00:00:00+00:00 Caching AJAX responses on the client by mapping App Engine’s datastore to JS objects. Implementing a Pythonic range() function in JavaScript https://yesudeep.com/blog/pythonic-range-in-javascript/ 2009-07-25T00:00:00+00:00 2009-07-25T00:00:00+00:00 A Python-style range() helper instead of typing out a sequence by hand.