Reading up on performance
45 deep · digging since dec 05, 25
- How Good Is Jon Hamm at Playing Jon Hamm?
Jon Hamm's ability to parody himself on screen is evaluated as a rare skill in the tricky practice of casting celebrities as fictionalized versions of themselves.
- Reverse Engineering ChatGPT Web: How OpenAI Built for a Billion Users
OpenAI powers ChatGPT's web experience for a billion users with React Router 7 streaming SSR, Tailwind CSS, off‑the‑shelf components, and aggressive feature flagging.
- ADA Q&A: Inside the world of Cyberpunk 2077 - Discover - Apple Developer
CD PROJEKT RED discusses balancing visual fidelity and identity with performance scaling to bring Cyberpunk 2077 natively to Mac using Metal, MetalFX, and the Game Porting Toolkit.
- 14 value stocks of companies primed for rapid growth through 2028 - MarketWatch
MarketWatch identifies 14 value stocks from the Russell 1000 Value Index with high revenue growth estimates through 2028, noting value stocks tend to outperform growth during high inflation.
- Fintech Engineering Handbook
Hacker News commenters debate whether monetary values must always be stored as integers, with quants arguing floats suffice for risk modeling but transfers require exact integer precision.
- Autoresearch, Claude and Constrained Optimization
An experiment using Claude Code to autonomously optimize a file compression algorithm over 10 iterations, achieving competitive results against standard tools by iterating on an LZSS-based approach.
- Iterating faster with TypeScript 7
The VS Code team incrementally adopted TypeScript 7, a Go port of the compiler, achieving 4–7× speedups in builds and editor tooling.
- Nub — an all-in-one toolkit for Node.js
Nub is a TypeScript-first toolkit for Node.js that provides a faster npm/pnpm run, a pnpm-compatible package manager, and a Node version manager, with no lock-in.
- How OpenAI Delivers Low-Latency Voice AI for 900M Users
OpenAI splits WebRTC into a stateless relay and a stateful transceiver, using the ICE ufrag for routing to serve 900M voice AI users with low latency.
- You might not need… a service worker
Service workers are essential for offline support, push notifications, and background sync, but other use cases are often better solved with simpler alternatives like HTTP caching or server-side logic.
- I rewrote PostHog's SQL parser, 70x faster, while barely looking at the code
PostHog's engineer used parallel Claude Code sessions to rewrite their SQL parser, achieving a 70x speedup by fuzzing against the old ANTLR-based parser as an oracle.
- GitHub - aidenybai/cnfast: Fast drop in replacement for `cn`
cnfast is a drop-in replacement for tailwind-merge that merges Tailwind classes 3.8x faster on average with byte-identical output.
- Kenneth Skovhus | Moving Linear from styled‑components to StyleX
Linear is migrating its React app from styled-components to StyleX for performance and stricter styling contracts, using a custom codemod and agent-assisted workflow.
- Building an HTML-first site doubled our users overnight
Replacing a SPA with plain HTML forms and server-rendered pages unexpectedly doubled a site's users, challenging assumptions about framework necessity.
- Vite 8.1 is out!
Vite 8.1 introduces experimental bundled dev mode for faster startup in large apps, chunk import maps, Wasm ESM support, and moves toward Lightning CSS by default.
- Astro 7.0 | Astro
Astro 7.0 ships a Rust compiler, Rust-based Markdown pipeline, queue-based rendering, Vite 8 with Rolldown, advanced routing, route caching, and AI-friendly dev server modes.
- Lighthouse agentic browsing scoring
Lighthouse's Agentic Browsing category scores sites as a pass/fail ratio for machine-readiness, using audits for WebMCP, accessibility tree integrity, stability, and llms.txt.
- TypeScript Performance in TanStack Table V9
TanStack Table V9 cut TypeScript type instantiations by 62-86% between alpha.54 and beta.12 using feature maps, interfaces, variance annotations, and explicit type arguments.
- invlpg – Premature Optimization is Fun Sometimes
A developer describes optimizing a 12KB ping-monitoring ring buffer down to 4KB using bitfields and tagged unions purely for enjoyment, despite the application not being memory-constrained.
- What’s new in Python 3.15 — Python 3.15.0b2 documentation
Python 3.15 introduces PEP 810, which enables explicit lazy imports to defer module loading and improve startup performance.
- CSS vs. JavaScript
CSS animations run off the main thread so they don't freeze during JS work, but libraries like Motion use the Web Animations API to avoid that pitfall.
- Bun v1.3.14 | Bun Blog
Bun v1.3.14 ships a built-in image processing API, 7x faster warm installs, experimental HTTP/2 and HTTP/3 clients and server, rewritten fs.watch(), and many other features and fixes.
- AI inference just plays by different rules
AI inference workloads demand unprecedented concurrency and throughput, exposing cloud storage limits that require a decoupled, software-defined layer to avoid catastrophic failures.
- How React streams UI out of order and still manages to keep order
React achieves out-of-order streaming by sending resolved components as hidden divs with script tags that swap them into suspense boundaries, bypassing sequential HTML parsing.
- The end of responsive images - Piccalilli
The new `sizes="auto"` HTML attribute, combined with `loading="lazy"`, lets browsers automatically determine the best image size to request, eliminating the need for manual `sizes` calculations.
- Do you even need a database?
The article argues that for many small-scale, read-heavy, or single-user applications, flat files like JSON can outperform a full DBMS, but warns that scaling or adding write concurrency will force you to rebuild a database.
- Python 3.15's JIT is now back on track
CPython's volunteer-driven JIT project achieved 11-12% speedups on macOS AArch64 and is back on track for Python 3.15, overcoming funding loss and earlier performance setbacks.
- Alysa Liu on Dancing Her Way to Olympic Gold: ‘The Music Carries My Body’ - The New York Times
Figure skater Alysa Liu tells a dance critic that music guides her body and free-spirited approach to performing in pursuit of Olympic gold.
- Better JIT for Postgres
pg_jitter provides microsecond-level JIT compilation for PostgreSQL using alternative backends, making JIT viable for OLTP queries where LLVM's overhead is too high.
- Bad Bunny Super Bowl Halftime Review: A History Lesson Full of Puerto Rican Pride - The New York Times
Bad Bunny's Super Bowl halftime show served as a history lesson and personal tribute, showcasing Puerto Rican pride through an intimate 13-minute set.
- Thread by @OpenAIDevs on Thread Reader App – Thread Reader App
OpenAI announced 40% faster inference for GPT-5.2 and GPT-5.2-Codex through inference stack optimizations, keeping same model weights.
- Securely indexing large codebases
Cursor cuts time-to-first-query from hours to seconds on large codebases by securely reusing a teammate's prebuilt index via Merkle tree-based syncing and access proofs.
- How the Cleveland Orchestra Stays at the Top of Classical Music - The New York Times
The Cleveland Orchestra's sustained excellence results from meticulous preparation, institutional culture, and collective discipline beyond just practice.
- Can Bundler be as fast as uv?
Aaron Patterson argues Bundler can match uv's speed through design changes like parallel installation and a global cache, not just a Rust rewrite.
- Ruby Programming Language
Ruby's redesigned homepage highlights the language's fun, readable syntax, rich gem ecosystem, and supportive community through testimonials from Matz, DHH, and others.
- What's new in Ruby 4.0
Ruby 4.0 ships Christmas 2025 with a new ZJIT compiler, redesigned Ractor ports, experimental isolated namespaces via Ruby::Box, and faster object allocations.
- 100k TPS over a billion rows: the unreasonable effectiveness of SQLite
SQLite achieves over 100k transactions per second on a billion-row dataset by avoiding network overhead, though durability and HA remain trade-offs.
Takes
Today we're publicly launching Cloud Run sandboxes. Here, I start, execute, and stop 1,000 sandboxes in 5s with an average of 500ms latency:
@steren
Ghostty is now indisputably the fastest terminal emulator at IO throughput, by a very large margin. On ASCII, Unicode, and CSI tests, Ghostty is more than 2x (double!) faster than any other leading "fast" terminal. These changes are directly in libghostty, too, so everyone wins. `time cat 150MB_ascii.txt`: - Ghostty nightly: 575ms - Ghostty 1.3.2: 1.5sec - Alacritty: 1.2sec - Kitty: 1.7sec - Warp: 3.8sec - iTerm2, Terminal: stopped after 60s `time cat 150MB_unicode.txt` (mixed languages): - Ghostty nightly: 536ms - Ghostty 1.3.2: 1.22sec - Alacritty: 1.05s - Kitty: 1.35s - Warp: 3.4s - iTerm2, Terminal: stopped after 60s `DOOM-Fire-Zig` (an IO test): - Ghostty nightly: 842fps - Ghostty 1.3.2: 532fps - Kitty: 485fps - Alacritty: 593fps - Warp: 577fps - iTerm2, Terminal: 60fps (yes, 60) To quickly address the "cat speed doesn't matter" naysayers: this is a direct test of how many bytes/second you can push through a terminal. It doesn't cover just "read big file" but also "how much can a TUI do". The tests above test various shapes of inputs (plain ascii, unicode/wide chars, csi-heavy loads, etc.). IO throughput is incredibly important. Most of these improvements apply to libghostty-vt consumers too, so any libghostty-based terminals will instantly see huge throughput improvements by simply upgrading (ABI compatible). I'll cover the exact improvements in a blog post in the future. These results are the result of 6 separate optimizations.
@mitchellh
Mind boggling to me that I can make a thing faster and there's always people that ask "but why?" What kind of mentality is that? The pursuit of excellence does not need justification. Also, I find in so many cases, we can't know the impact of an improvement until we do it. For example, one I've talked about before: Ghostty's high IO throughput has enabled terminal program (emulator and TUI) fuzzing at a speed thats incomparably fast to prior solutions. This has resulted in upstream patches to resolve issues in popular projects like btop, tmux, and more. Speed enabled that anecdotally example that lifted the tides of adjacent communities that don't rely on Ghostty technology at all. I didn't predict this. Make things better because they can be better and let the results naturally play out.
@mitchellh
Sonnet 5 is here. It's worse than Opus 4.8 on nearly every benchmark... Does that mean it's useless? Absolutely not. Use it with Claude Code Dynamic Workflows! 1. /model set to Sonnet 5 2. /effort set to Ultracode 3. Any complex task will kick off a dynamic workflow This will only become more powerful when Fable is back. You'll use Fable 5 as the superintelligent advisor and Sonnet 5 as the fast and efficient implementer.
@daniel_mac8
literally this. basically just never use google fonts and you'll be miles ahead of everyone else.
@Shpigford
A 6-person team is building task-specific AI models that are 4-8x faster than anything from OpenAI or Anthropic. 500K downloads on HuggingFace. No hype. Just better engineering winning on the merits. This is what "make something people want" looks like in the model layer.
@garrytan
OK, well. I ran /autoresearch on the the liquid codebase. 53% faster combined parse+render time, 61% fewer object allocations. This is probably somewhat overfit, but there are absolutely amazing ideas in this.
@tobi
TIL adding your terminal here will greatly speed up compile times. https://t.co/pfitVPwQls pic.twitter.com/UmPKQVW2Sj
@steipete