- 430: The Wild World of Keyboard Shortcuts in Web Apps
Shaw and Chris talk about how the keyboard shortcut situation is challenging, but in the best shape it's ever been in for our 2.0 editor. Between the operating system, browser, CodeMirror, and Emmet, the space is fairly crowded, but we've got enough room to offer lots of useful stuff. The commands are more findable than ever with our new Command system and the Omnibar.
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24 June 2026, 2:12 pm - 429: Why CodePen Rebuilt Its Realtime Service
We've had realtime features on CodePen for ages. Back when it was pretty damn hard. Our Collab Mode is an obvious one, where users can code together. (This "just works" in the 2.0 editor, it's not called anything special.) That and Professor Mode used to have realtime chat (until we pulled it because very few people used it). We went through iterations of this including our own implementations and using services like PubNub.
Code collaboration in realtime is particularly difficult. We used FirePad/FireBase for a while for this, and honestly that was a nice abstraction. Increasing the difficulty though, we need to layer on additional needs like syncing settings, presence, and just arbitrary message delivery (e.g. "a new build is ready!"). We used Ably for much of this for quite a while.
These days, our whole realtime system integrates with our caching layer, goes over the network using standard web sockets to our beefy Go servers, and is integrated with CRDTs/Y.js to keep everybody looking at the same thing. Plenty of open source software at work, but no more third-party services. This means lower operating costs and a simpler architecture. The cost is that problems are, well, our problems.
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16 June 2026, 10:00 pm - 428: Improving The Entire Billing System (is Very Worth It)
Rachel and Chris on the show this week to discuss a series of big changes over the last, say, six months or so with our billing system. We've essentially re-written this thing several times, and obviously this is the best time. Having three plans, two payment providers, teams, and fifteen years of history is a lot to manage.
An important aspect of the journey was getting the billing information into a single table in our database, and relying more on dynamic calls out to the payment providers when needed rather than trying to keep too much data in sync.
Of course we wanted to clean up the codebase and get payment APIs ported over to our latest system, but the biggest need this was all satisfying was UX. We wanted a proper pricing page, better pages for people to manage their billing, and really easy upgrade modals inside our 2.0 editor.
The good news is, it all worked.
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9 June 2026, 3:37 pm - 427: Next.js and The Journey of SSR
Having that first response from the server to users browsers be, ya know, full of good, useful, renderable HTML is certainly better than an empty <div id="app">. You can feel it and see it in the filmstrip view of the site loading. Not to mention you need it for at least things like <meta> tags if you want your URLs to "unfurl" properly on social sites.
Stephen and Chris jump on the podcast to discuss this journey for us as it relates to Next.js. We got it "for free" for our Ruby on Rails pages, but as we're slowly changing frameworks over the years, we've got new challenges, and some gray-hair inducing bugs.
We started on Next.js' "page router" and made changes to our Apollo Cache setup to support SSR. Then, over time, moved to the "app router" and did lots more work getting ready getting the most complex page on our site, the 2.0 editor, completely SSRd. That meant getting rid of using things like localStorage for anything view related and fighting bugs related to React somehow mounting itself to the wrong root.
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2 June 2026, 2:01 pm - 426: Browserslist in CodePen 2.0
Stephen and Chris chat about how the 2.0 editor (well, the compiler really) understands and supports Browserslist, a config format that lives in your package.json file that multiple blocks can understand and make browser support decisions against.
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27 May 2026, 9:38 pm - 425: Help Your Users Help You with Debug Logs
As we're getting close to rounding out the Beta period of the 2.0 editor, we're trying to close out any bugs we find or users report quickly. They could be browser-support related, network conditions related, account capability related, or just bugs in how the 2.0 editor and technology behind it works. It's complicated enough that the best way to debug things is to see exactly what the user sees when they have trouble.
A very cool side effect to having built the 2.0 editor with Apollo is that we have a nearly complete look at what is happening in the editor by virtue of the Apollo Cache (we talked about what that is here). We built a tool that can export that as JSON data, and we can load it locally to see exactly what the user sees. It's a bit fancier than that, doing things like saving browser console error logs and stuff, but that's the gist of it.
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12 May 2026, 9:02 pm - 424: File List Optimization
The 2.0 Editor can support hundreds of files per Pen, not to mention folders mixed in which don't count toward that total. This can be pretty weighty on the DOM and thus adversely affect performance. Especially as each file/folder has children, a variety of event listeners, are drag and drop enabled, etc. "Virtualizing" data like this is a common approach, but we've found if we just use IntersectionObserver to see if they are visible or not, "freeze" them if they aren't, and fade them in and out of life, it's a great solution.
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29 April 2026, 2:47 pm - 423: 2.0 Templates
Stephen and Chris hop on the ol' podcast to talk about all the ways that Templates are way better in 2.0 land. You've always been able to make your own templates, but now you can select one even after you've arrived in the editor. There is a new place (the create page) which features bookmarked and official templates (as well as your own). Most importantly, there is a way to set a "default template" now, meaning all new Pens will start with the same setup as the Pen you pick as that.
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22 April 2026, 1:23 am - 422: Supporting Packages
Alex and Chris talk about how the 2.0 Editor supports packages from npm. The trick is both simple and complex. The idea is simple. We detect the packages you want to use, list them in an (editable) package.json file, then turn that into a <script type="importmap"> in your HTML files that import those packages from esm.sh. Complex in that, well, all those steps are fairly difficult to get right, handle all edge cases, and do extremely quickly. All of which the CodePen Compiler does.
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14 April 2026, 4:50 pm - 421: View Control of the 2.0 Editor
Stephen & Chris look at the UI of the 2.0 Editor and show all the control you have over what you're looking at. Way more control than the Classic editor! We share some of the thinking behind it. Don't miss the Omnibar!
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8 April 2026, 8:50 pm - 420: What are Blocks?
With CodePen 2.0, we've got a new word we're using: Blocks. A way to think about Blocks is anything that processes code. They are added as steps to the CodePen Compiler as needed. For example, TypeScript is a block, because it processes files in the TypeScript syntax into JavaScript files. But something like Lodash is not a block. Lodash is a package from npm (which we also handle, but that's a topic for another podcast). Lodash doesn't process code, it's just a library that is linked up or bundled.
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11 March 2026, 1:28 am - More Episodes? Get the App