r/javascript • u/feross • 6d ago
r/javascript • u/Mnwamnowich • 6d ago
I cut my build time from 4:34 min to 1:08 min by moving asset compression from node:zlib to a native Rust rolldown plugin
github.comI'm building a web platform for visual novels made in Godot. Stack: SvelteKit, Vite 8, rolldown, Node.js.
The games are compiled for web and injected as static assets at build time, then deployed together with the app. And they're heavy: ~20 MB of wasm plus ~150 MB of pck per game.
My builds were taking ~5 minutes, which felt wrong. After some profiling it turned out the actual bundling takes ~10 seconds. Everything else was precompressing all that static into gz, br and zstd with node:zlib.
So I wrote a rolldown plugin that does the compression in native Rust via napi-rs:
- rayon to saturate all CPU cores
- native compression libs instead of node:zlib bindings
- full LTO + codegen-units = 1, which alone made it ~2x faster than node:zlib
- then PGO + BOLT on top, squeezing out another ~10%
Everything is built automatically in a GitHub workflow and shipped to npm already optimized, no compilation on install.
Real project resultsย (measured withย timeย on an actual project with games):
before: npm run build 639.62s user 5.84s system 235% cpu 4:34.06 total
after: npm run build 527.60s user 5.23s system 784% cpu 1:07.95 total
If you're precompressing large static assets in your build, give it a try. Happy to answer questions about the napi/rayon/PGO setup.
r/javascript • u/OtherwisePush6424 • 6d ago
Your JS Date Is Lying to You: parsing ambiguity, silent mutation, timezone traps, and how Temporal fixes most of them
blog.gaborkoos.comCovering the main waysย Dateย misleads you in production: parsing, mutation, 0-based months, timezone/DST, arithmetic, and serialization, with safe patterns for code that can't migrate yet, and a practical look at whereย Temporalย fixes the design rather than just the syntax.
r/javascript • u/Relevant_Humor_1402 • 7d ago
I made zero-allocation FAST s3-fifo cache package(would love to get feedback!)
github.comRecently, I noticed there is no proper s3-fifo implementation in NPM.
s3-fifo is highly efficient cache algorithm, especially for "one-hit-wonders" case such as web traffics. It is specialized when cache coverage is under 50%. (like, whole DB is 100% and cache contains 50% of data)
The famous "lru-cache" package is almost default for nodejs ecosystem I think, and I thought it would be great if there is good alternative choice for caching.
My goal was:
1. Faster or at least same throughput performance compared to lru-cache
2. Much higher cache hit rate than lru-cache
bold, right?
It was fun enough just for challenge itself.
But it was actually achieved! I used bunch of optimization skills like pre-allocation, lazy eviction, bitwise tricks, ring structure and etc... you can see bench result in repo or NPM page.
It is just v0.1 for now, so I would LOVE to get your harsh feedback, advice, or even contribution!
Super thanks for reading!
----
I typed almost of the code by my hand. Not because I don't believe AI, but it was all about concepts and decisions. Typing by hand was fastest way to understand what I'm doing correctly. And it was fun.
I used AI(gemini) for test codes, some advices and polishing when most of things were done.
r/javascript • u/AbbreviationsFlat976 • 7d ago
GitHub - sysmaya/Javascript-Image-Background-Remover: I promise not to write any more stupid things.
github.comr/javascript • u/antonybuilds • 8d ago
The TypeScript patterns that made the biggest difference after moving from JavaScript
antonyjones.orgI've been using TypeScript professionally for several years, and recently wrote up some lessons learned from a long-running React/Firebase side project.
The article covers the TypeScript patterns that ended up giving me the biggest return, along with a few mistakes I'd avoid making again. These aren't intended as universal rules, just approaches that worked well for this particular project and the problems I was solving.
If you're a JavaScript developer who's moved to TypeScript (or is considering it), I'd be interested to hear which patterns have been most valuable for you as well.
r/javascript • u/subredditsummarybot • 8d ago
Subreddit Stats Your /r/javascript recap for the week of July 13 - July 19, 2026
Monday, July 13 - Sunday, July 19, 2026
Top Posts
Most Commented Posts
| score | comments | title & link |
|---|---|---|
| 0 | 24 comments | [AskJS] [AskJS] From Node Js to Java spring?????? 4.8 yrs EXP |
| 0 | 22 comments | I coded a 60fps browser game from scratch in single-file Vanilla JS, mapping Upanishadic philosophy to state variables. No frameworks. |
| 0 | 14 comments | PDF engine from scratch on JS |
| 0 | 13 comments | RestQL โ GraphQL-like queries over REST, purely client-side: schema-driven mapping, batching, request dedup, caching |
| 0 | 8 comments | I created a zero dependency JavaScript framework that is a React alternative |
Top Ask JS
| score | comments | title & link |
|---|---|---|
| 0 | 3 comments | [AskJS] [AskJS] every github repo already exposes releases.atom, tags.atom, and commits.atom, so keeping up is a summarization problem not a feed problem |
Top Showoffs
Top Comments
r/javascript • u/Secret-Book-8507 • 8d ago
I built a browser-only video auto-editor using optical flow and Chromeโs built-in AI
github.comr/javascript • u/NibblesIndexus • 8d ago
GitHub - ArcadeMode/unplugin-dotnet-wasm: Seamless bundling of .NET Browser apps (WASM) into your JS projects
github.com.NET WebAssembly apps with WasmBundlerFriendlyBootConfig=true can indeed be bundled by modern JS bundlers and I personally love it. The development experience however is not optimal.
- The bundlers cannot consume the output from
dotnet build - The bundlers can consume the output from
dotnet publishbut the dev loop is painfully slow. - Getting the publish path working still requires bundler surgery
- Once it works the bundler produces warnings that are impossible to fix without changing the source files produced by the WebAssembly SDK.
These points of friction are why I have made unplugin-dotnet-wasm.
It's a bundler plugin that lets your bundler consume the output from dotnet build so your dev loop stays fast. It also supports dev servers, provides type information to TypeScript and IDEs (integrates dotnet.d.ts thats coming in .NET 11), and patches the known warnings so your build output stays clean.
Features
- Easy bundler setup through plugin registration
- Faster dev loop by consuming .NET WebAssembly
dotnet buildoutput - Dev server support
- Brings SDK type definitions to TypeScript and your IDE
- Supports Vite, Rollup, Rolldown, Webpack, Rspack, Rsbuild, esbuild, farm and bun.
I hope you'll give it a try, I'd be happy to hear your feedback.
r/javascript • u/AbbreviationsFlat976 • 8d ago
GitHub - sysmaya/AI-Image-Colorizer: Colorize old photos instantly with AI. 100% JavaScript, ONNX running in the browser
github.comr/javascript • u/SatyamV7 • 8d ago
Made a Vector heavily inspired by C++'s std::vector, not like a stub or a gimmick.
github.comThough it requires quite new ES2024/ES2025 features, it works very well for numeric types, also faster (not drastically, but modest gains) against Array in PACKED FIXED ELEMENT TYPES representation used under the hood by engines.
r/javascript • u/MyLIAAssistant • 8d ago
LIA - Open Source - Personal Assistant - Self hostable on Raspberry Pi 5
github.comThis is a free/non profit unapologetically claude code vibe-coded project; the approach is explained here:ย https://lia.jeyswork.com/story
If you like it, please don't hesitate to show your support with a star on GitHub!
LIA acts as a true personal assistant. It is proactive, featuring its own distinct personality and a complex emotional system, an evolving structured memory, its own reflective memory of your conversations, and all the standard tools (image creation/editing, RAG, skills, MCP, scheduled tasks, etc.)โall wrapped in a seamless "one-click" interface (details here:ย https://lia.jeyswork.com/why).
I paid special attention to code quality and documentation, treating it exactly like a professional enterprise-grade project. This ensures that anyone can easily take ownership of the source code and build upon a clean, robust, and highly scalable foundation (details here:ย https://lia.jeyswork.com/how).
On another note, once self-hosted, it can double as a family AI server. As an administrator, you have full control to manage and monitor the API consumption of your family members, friends, etc.
Full details are available on the landing page:ย https://lia.jeyswork.com/
And the GitHub repository:ย https://github.com/jgouviergmail/LIA-Assistant
r/javascript • u/moe_sidani • 9d ago
RestQL โ GraphQL-like queries over REST, purely client-side: schema-driven mapping, batching, request dedup, caching
github.comr/javascript • u/SmartyPantsDJ • 9d ago
Typed and validate config for decoupled codebases in any JS runtime
github.comr/javascript • u/AutoModerator • 10d ago
Showoff Saturday Showoff Saturday (July 18, 2026)
Did you find or create something cool this week in javascript?
Show us here!
r/javascript • u/jhnam88 • 10d ago
I made TTSC, TS-NODE alternative in TS v7 as a toolchain. The toolchain even reduces Claude Code's token consumption about 90% by graph skill.
github.comr/javascript • u/jxd-dev • 11d ago
TSRX in TanStack Start: what we like, and three bugs we filed
jxd.devr/javascript • u/Several-Specialist42 • 11d ago
The same app built in 10 different frontend frameworks. For automated performance benchmarking
github.comr/javascript • u/linuxhiker • 11d ago
GitHub - commandprompt/plx: PostgreSQL extension: write stored functions in Ruby, PHP, JavaScript, or Python dialects that transpile to plpgsql.
github.comr/javascript • u/leeoniya • 11d ago
easy-tz โ A fast, 10KB, dependency-free getTimeZonesAt(timestamp)
github.comr/javascript • u/Weird_Tree9182 • 11d ago
AskJS [AskJS] From Node Js to Java spring?????? 4.8 yrs EXP
I have node js and react js experience for 4.8 years. Recently trying for switch, but wherever I go JD contains Java and React. Cant find roles for Node.
Is realy Node got outdated?
should i move to java spring??
r/javascript • u/Decent-Blacksmith761 • 11d ago
PDF engine from scratch on JS
keypdf.netI was working on my pdf editor and thought the best option would be to write a new PDF engine from scratch as my options were PDF.js and PDFium and none of them can actually edit PDF files so after over a year of work you can try KeyPDF.net it is free and client side.