In this episode of Svelte Radio, we welcome Jeppe as a new permanent host and sit down with Paolo Ricciuti, Svelte maintainer and Senior Software Developer at Mainmatter, to dive deep into Svelte custom renderers. Paolo walks us through how custom renderers work (using React's approach with React DOM, Ink, and React Native as context), explains the technical challenges of bringing this capability to Svelte 5—including the template element trick, CSP issues, and runtime modifications—and shares his proof-of-concept work enabling Svelte to render to non-DOM targets like terminals and native mobile apps via Lynx.js. The discussion touches on potential use cases like Threlte for 3D graphics, the importance of this feature for Svelte adoption, and wraps up with picks including Screen Studio, TMCP, and Advent of Svelte.

Guest

• Paolo Ricciuti — Svelte maintainer and ambassador, Senior Software Developer at Mainmatter

New Host

• Jeppe joins as a permanent co-host!

Topics Discussed

Custom Renderers Overview

• Svelte Custom Renderers website
• What custom renderers are and why they matter
• How React separates React (the diffing library) from React DOM (the renderer)
• Examples of React custom renderers: 
  • Ink — React for terminal/CLI applications
  • React Native — React for iOS/Android native apps
  • Remotion — React for programmatic video creation
  • React PDF renderer for generating documents

Svelte's Technical Approach

• How Svelte 5 uses the

Guest
Ilja - Berlin-based developer specializing in building websites and data visualizations for NGOs. Svelte Ambassador.

Topics Discussed

• Working with NGOs vs. traditional businesses
• Budget constraints and project-based funding
• The AfroZensus project
• Svelte 5 migration
• Berlin Svelte Meetup announcement

Berlin Svelte Meetup

• Date: December 9th (Tuesday)
• Venue: Datawrapper's office in Berlin
• Talks: Peter from XYFlow presenting SvelteFlow, plus more
• Registration: https://svelte-berlin.de/

Links Mentioned

Tools & Libraries

• svelte-render-scan (Visual debugging tool by Stanislav Khromov): https://github.com/khromov/svelte-render-scan
• svelte-inspect-value (Value inspector component): https://github.com/ampled/svelte-inspect-value
• SvelteFlow (Node-based UI library): https://svelteflow.dev/
• Friendly Captcha (GDPR-compliant captcha): https://friendlycaptcha.com/
• SparklePost (Native-feeling PWA demo): https://sparklepost.vercel.app/
• @component documentation: https://svelte.dev/docs/svelte/basic-markup

Companies & Organizations

• Datawrapper: https://www.datawrapper.de/
• GitButler: https://gitbutler.com/
• XYFlow: https://xyflow.com/

Projects

• Academic Freedom Index: https://academic-freedom-index.net/
• AfroZensus: https://afrozensus.de/
• AfroZensus Dashboard: https://data.afrozensus.de/

Courses

• Practical Accessibility by Sara Soueidan: https://practical-accessibility.today/

Unpopular Opinions

• Kevin: More people should self-host
• Brittney: Lost free Copilot access
• Antony: Store states, not effects
• Ilya: JSDoc is superior to TypeScript

Picks

• Kevin: SparklePost, "You can just do things", The Hierarchy book series by James Islington
• Brittney: @component documentation
• Antony: Friendly Captcha
• Ilya: svelte-render-scan, svelte-inspect-value, Practical Accessibility course

In this episode, Stanislav Khromov joins the Svelte Radio team to discuss his work on Svelte Bench, a

benchmarking tool that scientifically measures how well different LLMs understand and write Svelte 5 code.

The conversation explores the challenges of AI-assisted coding with Svelte 5, the development of the official

Svelte MCP (Model Context Protocol) that provides LLMs with documentation and auto-fixing capabilities, and

the surprising performance differences between major AI providers. Stanislav also shares insights on working

with AI tools, the future of local models, and the economics of AI coding assistants.

Notes

• Stanislav Khromov
• Svelte Bench
  • GitHub
• Svelte MCP
• Anthropic Spending VC Money

Unpopular Opinions

• Kevin: Serverless is overrated
• Stanislav: OpenAI has the worst models of the big three
• Antony: Heat Pumps are bad
  • Technology Connections
  • Tech Ingredients

Picks

• Kevin: Kasai Hibachi Grill (now tested, and can confirm, it is PENG!)
  Stanislav: Ball x Pit
  Antony: Saunas By the Sea

In this episode of Svelte Radio, Ken Kunz joins the hosts to discuss his journey with Svelte, from discovering it

through Rich Harris's "Rethinking Reactivity" talk to building complex financial applications. Ken shares his

experience working on Trading Strategy, a decentralized finance platform, and the challenges of implementing

sophisticated charting solutions.

The conversation also covers Ken's memorable Svelte Summit talk where he

recreated the Macrodata Refinement interface from the TV show Severance, complete with props and staying in

character throughout. The episode touches on testing philosophies, state management with his library Svelte-

FSM, and the newly launched Svelte Society Chicago chapter.

Notes

• Trading Strategy
• LayerChart
• TradingView Lightweight Chart
• xstate
• svelte-fsm
  • Talk
• Runed
• Macrodata Refinement Talk
  • GitHub Repo
  • Website
• Bert B's Svelte Summit Talk
• Svelte Chicago

Picks

• Kevin: Zen Browser
  • Zed
  • Zod
• Antony: n8n
  • Active Pieces
• Brittney: Tab Groups!
• Ken: Rock Climbing!
  • Brene Brown

Summary

In this episode of Svelt Radio, the hosts welcome Jeppe Reinhold from Chromatic to discuss the dramatic

improvements in Storybook's Svelte integration. Jeppe shares how a critical video by Brittany struggling with

Storybook setup sparked a complete overhaul of the Svelte experience, leading to better collaboration with the

Svelte core team and significant enhancements in functionality. 

The conversation covers new features like Svelte

CSF for writing stories in native Svelte syntax, improved testing capabilities, support for async components, and

upcoming features in Storybook 10. The team also discusses the philosophy behind component-driven

development, the challenges of integrating with remote functions, and Storybook's future direction including AI

support and better theming capabilities.

Links

• Storybook
  • Storybook Svelte Guide
• addon-svelte-csf

Unpopular Opinions

• Antony: Svelte is an independent project! Don’t throw it in the bin
• Jeppe: I like GANTT charts

Picks

• Antony: Castles!
• Brittney: Spain!
• Jeppe: Tuple

Summary

In this episode, Simon Holthausen from the Svelte team joins to discuss remote functions and async Svelte, two

experimental features that are changing how developers interact with data in SvelteKit applications. Remote

functions offer a new RPC-like approach that provides better type safety, more granular data loading, and

improved developer experience compared to traditional load functions and form actions. The conversation

covers the technical implementation, design decisions, and future possibilities including caching, streaming, and

integration with Svelte's upcoming resource API. Simon also explains how async Svelte enables top-level await

in components with coordinated loading boundaries, making asynchronous work much easier to manage in both

SSR and SPA contexts.

Links

• Remote Functions Documentation
• Remote Functions Video by Simon
• Follow-up Video by Simon

Picks

• Simon: Elgato Wave Microphone
• Kevin: CalDigit Thunderbolt 5 Dock TS5 Plus

Summary
We're putting the band back together. Svelte Radio is officially back. This first episode is a bit of catch-up. Not a ton of Svelte chatter. Look forward to many fun and interesting episodes.

Next week we talk with Simon about Remote Functions. Don't miss it!

Show Notes

• Introducing SvelteKit Remote Functions, by Simon Holthausen
• SvelteKit Remote Functions tips: Auth guards, managing asynchronous, query.batch
• Svelte Bench
• Tembo

Hot takes

• Kevin: AI generates a lot of Workslop if you're not careful.
• Antony: Find something common and differentiate
• Brittney: Cats are better than dogs.

Picks

• Kevin: Slow Horses
• Brittney: Cate Cafés
• Antony: Gary's Economics 

Summary
In this episode we sit down with Timothy Cohen and talk about his project SampleKit and Svelte 5.

Sponsored by Svelte Summit
Svelte Summit is an event dedicated to Svelte and everything that is happening in the community. Don't miss it! It's going to be an absolute blast. It's happening on May 8 and 9, 2025 in Barcelona Spain.

• Background
  • Wes Bos & Scott Tolinski
  • How svelte works under the hood
  • Odin Project - https://www.theodinproject.com
  • MOOC - CS50 Harvard X
• SampleKit - https://www.samplekit.dev
  • 3 different things
    • Preprocessor (mdsvex)
    • melt-ui
    • alternative to mdsvex
  • Demos
    • caprover
    • coolify
    • dokku
    • shopify
    • Sasa Juric
  • Articles
    • TypeSafe Fetch Handler - https://www.samplekit.dev/articles/typesafe-fetch-handler
    • SvelteKit Search Params - https://github.com/paoloricciuti/sveltekit-search-params
• What do you think about Svelte 5?
  • Reactive Statements
  • Snippets
• Picks
  • Timothy: Crafting Interpreters by Robert something (look up)
  • Kevin: New York
• Email: [email protected]
• GitHub: timothycohen

Summary
In this episode we sit down with Dominik G — a Svelte maintainer — and talk about Svelte 5 and the new Environment API in Vite 6.

Sponsored by Svelte Summit
Svelte Summit is an event dedicated to Svelte and everything that is happening in the community. Don't miss it! It's going to be an absolute blast. It's happening on May 8 and 9, 2025 in Barcelona Spain.

Discussion

• Who is Dominik?
  • vite-ecosystem-ci
• Dominiks talk at JSNation
• Vite
  • Environment
    • Björn Lu
    • Cloudflare Workers
      • Miniflare
    • Samuel Inlang environments for i18n
    • Jeppe Reinhold (Storybook)
• Svelte 5
  • SvelteKit and how the Environment
  • Error Boundaries (PR here)
  • Migrating
    • $: to run function
    • Don’t reach for effect, use derived!
    • You can use effect to get the same functionality as onMount/Destroy
• Hackathon
  • Return to Castle Wolfenstein
  • Wolfensvelte
  • Threltemania

Summary
In this episode we sit down with Rich Harris — creator of Svelte — and talk about the recent development of Svelte and SvelteKit.

Sponsored by Svelte Summit
Svelte Summit is an event dedicated to Svelte and everything that is happening in the community. Don't miss it! It's going to be an absolute blast. It's happening on May 8 and 9, 2025 in Barcelona Spain.

Discussion

• Rich Harris introduction
• Svelte 5 Feedback
  • Simon and Paolo shoutout
  • New command line tool: npx sv migrate svelte-5
• Advent of Svelte
  • Svelte
    • error boundaries 
    • bind: set/get
    • Actions 
    • Async stuff
      • Load in Kit
      • Stores not scoped!!! WHY NOT?
  • Kit
    • State based equivalents of the stores
      • AsyncContext/AsyncLocalStorage
    • Error boundaries built-in
    • Partial Pre-rendering
• JSNation
• Hot takes
  • Rich: We need more hot tak
  • Kevin: SQLite is the best
• PIcks
  • Rich: 
    • Bluesky
    • Book - Lifespan, David Sinclair