Protecting apps with Arcjet through WebAssembly

The JVM-to-Web journey continues! In this episode, Thomas Steiner welcomes the original author of Scala.js, Sébastien Doeraene, to discuss the major, experimental leap to WebAssembly. You'll learn why the team decided to target Wasm now and how it complements the existing JavaScript emission. This episode offers a technical deep-dive into how Scala's powerful, nominal type system maps its objects and classes onto Wasm GC, and examines the critical details of interoperability, including what happens when a Scala object crosses the boundary to a JavaScript function. Finally, Sébastien covers the current status of the Wasm ecosystem for Scala.js, and the key limitations you need to know before you flip the `withExperimentalUseWebAssembly(true)` switch. Tune in to discover how a mature typed language is laying a fast, new foundation on the web!   Chapters: 0:00 -  Commonalities between composing music and composing compilers 1:38 - Scala, Scala.js, Scala Native, and the Scala Center 11:01 - The "elevator pitch" for Scala.js 14:59 - Is Scala.js competing with TypeScript? 20:31 - What motivated the decision to target Wasm? 26:40 - ] How Scala.js utilizes Wasm GC 31:24 - What's actually crossing the boundary between JS and Scala.js? 37:37 - BigInt support in Scala.js 38:38 - The status of the library ecosystem for the Wasm target 41:40 - Sébastien's hobby project ported to Scala.js 44:02 -  Is the Wasm backend purely a Scala.js thing for browsers? 52:38 - What developers should be aware of before flipping that `withExperimentalUseWebAssembly(true)` switch 58:28 -  What Wasm proposals are you waiting for to unlock new features in Scala.js? 59:57 - Wasm, but not    Resources:   Sébastien Doeraene on GitHub → https://goo.gle/4pMPufo  Sébastien Doeraene at EPFL → https://goo.gle/3KTZZhu   Ensemble vocal Évohé → https://goo.gle/4pApQu5  Scala → https://goo.gle/4iYZwY1  Scala.js → https://goo.gle/4oYze9E  Scala Native → https://goo.gle/4rX4hp0  Scala Center → https://goo.gle/44uffZ8  Scala to TypeScript → https://goo.gle/4j37ZcM  Tyrian → https://goo.gle/4iZCOik  Laminar: https://laminar.dev/   Scala.js WebAssembly backend → https://goo.gle/4oT4bvV  Announcing Scala.js 1.19.0 → https://goo.gle/4aSYM4F  Wasm GC proposal: https://github.com/WebAssembly/gc  JSPI proposal → https://goo.gle/4s5cIik  Scala.js Interoperability → https://goo.gle/4afJdE1  Scaladex homepage with stats → https://goo.gle/4ja7jCr  FunLabryrinhte (Scala) → https://goo.gle/4oTghoL   FunLabryrinhte (original) → https://goo.gle/3KA8EWx  Bringing Scala to Server-Side Wasm → https://goo.gle/4pgwC7v  Scala.js Wasm Limitations →  https://goo.gle/4s1jOnN  Custom descriptors proposal → https://goo.gle/4p8I7Og  Stack Switching Proposal → https://goo.gle/4pJG8B1  JS Primitives Builtins proposal → https://goo.gle/4akAnor  Shared-Everything Threads proposal → https://goo.gle/3MCCxGd  Watch more WasmAssembly → https://goo.gle/WasmAssembly  Subscribe to Chrome for Developers → https://goo.gle/ChromeDevs #WebAssembly #Wasm #ChromeForDevelopers #Chrome   Speaker: Thomas Steiner Products Mentioned: Web Assembly (Wasm),  Chrome,  WebAssembly for Chrome  

Join WasmAssembly host Thomas Steiner for a deep dive into the world of Kotlin/Wasm with Zalim Bashorov from JetBrains! This episode of WasmAssembly explores how Kotlin, known for being concise, multiplatform, and fun, became the recommended language for Android, and why JetBrains decided to expand its reach to WebAssembly. They discuss how people are currently using Kotlin on the Web, the power of Kotlin Multiplatform, and the future of Kotlin/Wasm, covering exciting recent and new proposals like Garbage Collection, Exception Handling, and Shared-Everything Threads. Tune in to hear about the tooling, next milestones, and the evolving landscape of Kotlin development.   Chapters: 0:00 - Introducing Zalim from JetBrains 2:19 - Kotlin: Concise. Multiplatform. Fun. But what does this mean? 9:05 - How did Kotlin become the recommended programming language for Android? 16:17 - Why did JetBrains decide to support WebAssembly? 25:36 - People use Kotlin on the Web, but how? 31:15 -  What is Kotlin Multiplatform? 37:48 - Understanding canvas-rendered apps 41:17 - Could the HTML-in-Canvas proposal help? 43:59 - New Wasm proposals Zalim is excited about 54:29 - What about Kotlin on the server? Resources: Zalim Basharov on LinkedIn → https://goo.gle/4pis0y2  StackOverflow 2025 developer survey results → https://goo.gle/3WZuchN  Kotlin Programming Language → https://goo.gle/4ifxZkU  Google I/O 2019: Empowering developers to build the best experiences on Android + Play → https://goo.gle/3LLwpen  Kotlin Is Everywhere: https://goo.gle/4rlvdPc  Kotlin/Native → https://goo.gle/3LNk1KM  Kotlin/JavaScript → https://goo.gle/3XxkDH0  Kotlin/Wasm → https://goo.gle/4r53NwP  Kotlinx.browser → https://goo.gle/4o9WRvJ  Kotlin/Wasm browser template → https://goo.gle/49tzl9c  Get started with Kotlin/Wasm and Compose Multiplatform → https://goo.gle/3X8cmsW  Get started with Kotlin Multiplatform → https://goo.gle/48njI20  HTML-in-Canvas proposal → https://goo.gle/48sy8wX   Garbage collection proposal → https://goo.gle/4i4CgHw  Exception handling proposal → https://goo.gle/483coav  Shared-everything threads proposal → https://goo.gle/4474V9e  Stack switching proposal → https://goo.gle/49XiMCH  All ways to reach Zalim → https://goo.gle/3LG78lT   

Get ready for WasmAssembly episode 16! Host Thomas Steiner sits down with Patrick Dubroy and Mariano Guerra, authors of the ebook "WebAssembly from the Ground Up." Discover how they're teaching Wasm by building a compiler in JavaScript, why writing WebAssembly by hand is crucial, and their thoughts on the future of compiler education. Tune in to learn about Ohm, the surprising omission of WAT, and what a potential part 2 of their book might cover! Chapters: 0:00 - Welcoming Patrick and Mariano, authors of "WebAssembly from the Ground Up 1:34 - How the book came to be 5:34 - How the co-authors met 9:13 - Who should learn WebAssembly by actually writing it? 13:13 -  Is it time to retire the Dragon Book? 17:42 - What is Ohm, what it has to do with the programming language Wafer, and why they chose Ohm for the book 27:22 - Compiling Ohm grammars to Wasm 30:22 - The on-purpose omission of the Wasm text format WAT 38:27 - A potential part 2 of the book 43:36 - The biggest surprise when writing the book 50:42 - Wasm, but not Resources: Mariano Guerra on LinkedIn: https://goo.gle/4gtIq3e  Patrick Dubroy on LinkedIn: https://goo.gle/46t7Ucx  WebAssembly from the Ground Up: https://goo.gle/3IvlqnT  Learn WebAssembly: https://goo.gle/46v50E0  WebAssembly website Issue: Consider adding a pure Wasm tutorial: https://goo.gle/46MlMzK  Let's Build a Compiler, by Jack Crenshaw: https://goo.gle/4gwQGzz  Simpletron Machine Language and Compiler from Deitel's Java book: https://goo.gle/4nK5CNf  Little Riak Core Book: https://goo.gle/48rMNtF   Failed PR "Initial tests for globals" to the Wasm spec:https://goo.gle/3IwfQ4I  Short lived "WebAssembly Weekly" newsletter: https://goo.gle/3IgQYOp  The Dragon Book: https://goo.gle/4pLnYPM  Ohm: https://goo.gle/3VWpu3B  Human Advancement Research Community (HARC):https://goo.gle/3Iqbf47  Communications Design Group (CDG):https://goo.gle/4px8zlK  Forth dialect implemented in C, JavaScript, WebAssembly and compiled from C to asm.js and WebAssembly: https://goo.gle/3KvZLfV  Minimal Object Oriented runtime in WAT and WasmGC:https://goo.gle/4nxxS5m  wasm-tools: https://goo.gle/4nyisxQ  Apple's Pascal "syntax" poster: https://goo.gle/4mvhX6X  Niklaus Wirth: https://goo.gle/424Bzax  Lilith Computer: https://goo.gle/4nECeru  Oberon System: https://goo.gle/4pvyP03  Bill Hader on feedback: https://goo.gle/3K9R76U  How Julia Evans asks for feedback: https://goo.gle/4gxwFZv  Patrick's blog post "Reflections on writing a book": https://goo.gle/4gx3Jkk  Quarterback: https://goo.gle/4gvIcc5  Max Bernstein's blog: https://goo.gle/46vlwUD  Thorsten Ball's newsletter: https://goo.gle/4pvoWzl  Gleam Programming Language: https://goo.gle/46H66hj  Sonic Pi: https://goo.gle/3I6z6Wv  Future of Coding Newsletter: https://goo.gle/3Isd4xi  Patrick Dubroy on Bluesky: https://goo.gle/3VZ6v8C   Patrick Dubroy on Mastodon: https://goo.gle/4pvzazR  Mariano Guerra on Bluesky: https://goo.gle/4pxInYa  Mariano Guerra on Mastodon: https://goo.gle/4n6OXn3  WebAssembly from the Ground Up ebook on Bluesky: https://goo.gle/4prbIUd  WebAssembly from the Ground Up ebook on Mastodon: https://goo.gle/4gxBwtX   

 In this episode of WasmAssembly, host Thomas Steiner welcomes Thomas Lively from Google, the new co-chair of the W3C WebAssembly Community Group. Taking over the role from past guest Deepti Gandluri (episode #2), we seize the opportunity to ask Lively the exact same three questions we posed to Deepti—listen back to compare their perspectives! In the second half, the two Thomases dive deep into the proposals Lively is personally championing, covering Custom Descriptors and JS Interop, and the highly-anticipated Shared-Everything Threads.   Chapters: 0:00 -  The Wasm team "Thomas" confusion 0:57 - Thomas' way into Google's Wasm team  4:10 - Wasm CG vs. Wasm WG  9:39 -  Is Wasm standardization moving slowly? 17:58 - Wasm at Google and the Chrome team  22:33 - The Custom Descriptors and JS Interop proposal  35:02 - The Shared-Everything Threads proposal  43:28 -  Wasm, but not Resources: Thomas Lively on LinkedIn → https://goo.gle/45U8uRA  WebAssembly Community Group → https://goo.gle/3K0qSj3  From asm.js to Wasm with Emscripten creator Alon Zakai → https://goo.gle/47zQTj9  CG, WG, W3C, Deepti—Wasm standardization with Deepti Gandluri → https://goo.gle/4ndWX5X  Custom Descriptors and JS Interop → https://goo.gle/4ggStbY   WebAssembly threads →​​ https://goo.gle/45Z0kaI  Shared-Everything Threads → https://goo.gle/47BnLYG  Thomas Lively on Bluesky → https://goo.gle/4gcm2v8   

In this episode of WasmAssembly, your host Thomas Steiner is joined by Ömer Ağacan and Martin Kustermann from the Dart team at Google. They explore Dart, the language behind Flutter, and how Dart nearly landed in V8 alongside JavaScript, and why Flutter doubled down on Dart and WebAssembly Garbage Collection (WasmGC). Ömer and Martin then share insights on Dart's performance leap from dart2js to dart2wasm, its potential beyond the browser, and what the WasmGC transition means for developers and the broader ecosystem. Finally, they look at Jaspr, Dart-only web apps, or how different browsers are handling WasmGC. This episode again is packed with sharp technical detail and bold visions for the future of WebAssembly. Resources: Dart → https://goo.gle/4kfijgD  Flutter → https://goo.gle/4kh4jDi  Before Flutter | Rubber Duck Engineering | Episode #100 → https://goo.gle/4nujV9g  State of Developer Ecosystem Report → https://goo.gle/4lrmya6  What's new in Flutter → https://goo.gle/44xx0Gl   Dart & Flutter momentum at Google I/O 2025 → https://goo.gle/3TgUr1p  Accessibility in Flutter on the Web → https://goo.gle/4l2xfQB  Stateful hot reload in DartPad → https://goo.gle/4nokFg1  WebAssembly (Wasm) compilation → https://goo.gle/3I8Ngpx  Support for WebAssembly (Wasm) → https://goo.gle/45L0wdR  WebAssembly Garbage Collection (WasmGC) now enabled by default in Chrome → https://goo.gle/3G7qLAS  Wasm-feature-detect library → https://goo.gle/4evqS5Y  A new way to bring garbage collected programming languages efficiently to WebAssembly → https://goo.gle/4keW0rt      [dart2wasm] Support non-JS wasm runtimes → https://goo.gle/44wr3t3  Safari bug: Umbrella: Using Canvas image sources between different canvases and canvas types is slow → https://goo.gle/3TmuSvM  Firefox bug: OffscreenCanvas.transferToImageBitmap incurs a copy → https://goo.gle/3GoIGD2  Ömer Ağacan on LinkedIn → https://goo.gle/4lA6fYB Martin Kustermann on LinkedIn → https://goo.gle/3TffQbc    

On this WasmAssembly podcast episode, host Thomas Steiner speaks with David Kircos from Quadratic. They discuss how Quadratic's spreadsheet utilizes WebAssembly to enable scientific computing directly in the browser, leveraging tools like Pyodide, pandas, and numpy. The conversation also covers practical challenges such as bundling large-scale Wasm applications, exploring browser limitations, and Quadratic's integration of AI.   Resources: David Kircos on LinkedIn → https://goo.gle/4jcpQg6  Building on the modern web app architecture → https://goo.gle/4hPpcnH  Pyodide → https://goo.gle/445YEv9  Pandas → https://goo.gle/4ldvkcp  Numpy → https://goo.gle/3E1qSNb  Esbuild-wasm → https://goo.gle/4hRqNJL  Using JavaScript in a spreadsheet → https://goo.gle/3XIRk4W  Making API requests from your spreadsheets → https://goo.gle/3FQQPja  Quadratic Python roadmap: building a spreadsheet developers love → https://goo.gle/446dLot  ES module integration proposal → https://goo.gle/3C8wd3L  AI spreadsheets are here: Quadratic + GPT → https://goo.gle/4hZpFUB   Database connectors → https://goo.gle/3QXMs8g  SQLite Wasm → https://goo.gle/3FSn3dW  Quadratic's GitHub organization → https://goo.gle/4jhWqNY   

Feature phones? Yes, they still make them. And they run Wasm! In this WasmAssembly podcast, Thomas Steiner hosts Thomas Barrasso from CloudMosa to talk about the Cloud Phone platform and what it takes to run WebAssembly on tiny feature phones by streaming Web apps from a remote server that runs Chromium.  Resources: Thomas Barrasso on LinkedIn → https://goo.gle/3Fxbvwg  CloudMosa (Puffin) → https://goo.gle/42bNe7M  Cloud Phone → https://goo.gle/4c0xfwB  Building web apps for Cloud Phone → https://goo.gle/4bz1Pxn  Cloud Phone simulator → https://goo.gle/4c0fRYZ  KaiOS → https://goo.gle/4kx6C6z  Puffin Cloud Isolation → https://goo.gle/4bFMxqK   Telegram client for KaiOS → https://goo.gle/3DRL581  Wasm implementation of algorithms used in Telegram → ​​ https://goo.gle/43PTDH1  Stolen Focus book → https://goo.gle/43PTDH1  Reach out → https://goo.gle/4bY9BRs  Thomas' email: [email protected]

In this WasmAssembly podcast episode, Sean Isom and Mendy Berger from renderlet join host Thomas Steiner. Discover renderlet, a WebAssembly framework for writing graphics code that runs on any platform.  Resources: Mendy Berger on LinkedIn → https://goo.gle/4b1y205  Sean Isom on LinkedIn → https://goo.gle/4hyO8Rb  Renderlet → https://goo.gle/3QsfjRy  renderlet Wasm I/O talk → https://goo.gle/42Z4nm4  renderlet Wasm I/O slides → https://goo.gle/4b7qCs1  Drawing to canvas in Emscripten → https://goo.gle/4i4Kazu  Multi-draw indirect GPU feature → https://goo.gle/3EH8zNg  Mesh shaders → https://goo.gle/40Y2Jyu  Work graphs → https://goo.gle/42X96ot  When in doubt, writeBuffer() → https://goo.gle/4jWjLWm  Fine grained control of memory proposal → https://goo.gle/4hHMvkj  Streams.wit → https://goo.gle/4gHkQhT   wasi-gfx talk: → https://goo.gle/4gU0tyo  wasi-gfx proposal → https://goo.gle/3QmYY0z  Web IDL → https://goo.gle/3X7Ea10  WIT → https://goo.gle/3CYzp2W  Webidl2wit → https://goo.gle/412whef  Mendy Berger on Mastodon → https://goo.gle/3D7XPXH  Sean Isom on X → https://goo.gle/41lY5vN

WebAssembly is known for its speed and security, but can it be applied to enhance application security as a whole? Join Arcjet's CEO David Mytton and host Thomas Steiner on WasmAssembly as they delve into Arcjet's innovative use of Wasm for crucial security functions like bot detection, rate limiting, and data redaction, providing developers with a powerful yet manageable security toolkit. Resources: Squishy Wasm apps using Extism with Dylibso's Steve Manuel - WasmAssembly → https://goo.gle/3VFcf7J  David Mytton's blog → https://goo.gle/3C7kXFv  Console Devtools podcast episode with Fermyon's Matt Butcher → https://goo.gle/3C8mQBQ  Arcjet → https://goo.gle/40r7dNH  Arcjet Wasm blog posts → https://goo.gle/3WqTNQG  Arcjet example app → https://goo.gle/3E3We5n  @arcjet/next package → https://goo.gle/3DXvyDh  Arcjet JS SDK → https://goo.gle/4h4UyqY  Jco → https://goo.gle/4ecjdIC  jco example → https://goo.gle/4gwhBLu  Wasm-bindgen → https://goo.gle/3WrZVs0  Arcjet-js PR where we switched, with some comments on reasoning → https://goo.gle/4hHkJEf  Componentize-py → https://goo.gle/3CdOUUn  Componentize-dotnet → https://goo.gle/42oiNMu  ComponentizeJS → https://goo.gle/3OUNjFG  Wasm Interface Type (WIT) → https://goo.gle/4fnXMFf  Extism → https://goo.gle/3E5waa2 

Join Thomas Steiner as he chats with Thorsten Hans, Senior Cloud Advocate at Fermyon, about the exciting world of WebAssembly serverless functions and microservices with the Spin framework. Discover how Spin uses WebAssembly for lightning-fast cold starts and great portability, and explore the advantages of building microservice applications with Spin's diverse language support. Thorsten and Thomas also delve into the role of WebAssembly standards in shaping the future of cloud-native development. Tune in for this insightful conversation on the cutting edge of WebAssembly technology!  Resources: Thorsten Hans' Fermyon blog posts → https://goo.gle/3ZCRJpL  Thorsten Hans on X → https://goo.gle/49xok4J  Thorsten Hans' blog → https://goo.gle/49xooBv  Thorsten Hans on LinkedIn → https://goo.gle/3Dh9frZ  Thorsten Hans on joining Fermyon → https://goo.gle/3PeO7pb  Till Schneidereit on LinkedIn → https://goo.gle/49ApA73   Fermyon Spin → https://goo.gle/3ZQdTGb  Introducing Spin → https://goo.gle/3VBBeZI   Fermyon Spin on GitHub → https://goo.gle/3VEEymR  Building Spin Components in JavaScript → https://goo.gle/3ZCSZct  WasmAssembly episode "Squishy Wasm apps using Extism with Dylibso's Steve Manuel": → https://goo.gle/3VFcf7J  Spin JS/TS SDK → https://goo.gle/41zjrGw  ComponentizeJS → https://goo.gle/3OUNjFG   WASI HTTP → https://goo.gle/3MQvK8L  SpiderMonkey → https://goo.gle/4gIR1Ps  StarlingMonkey → https://goo.gle/3De6IyM  Spin Rust SDK → https://goo.gle/49zRznq  Spin SQLite storage → https://goo.gle/4iATEUo   Spin Serverless AI → https://goo.gle/49yWvJa