--- title: "How we turned the Replay keynote surprise into an open-source embedded playground" url: https://daily.dev/posts/how-we-turned-the-replay-keynote-surprise-into-an-open-source-embedded-playground-jvmlbu4zy source_url: https://temporal.io/blog/how-we-turned-replay-keynote-surprise-open-source-embedded-playground type: article source: "Temporal" published: 2026-08-06T10:37:26.621Z updated: 2026-08-06T10:40:24.267Z tags: ["iot", "embedded"] reading_time: 23 upvotes: 0 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # How we turned the Replay keynote surprise into an open-source embedded playground **[Temporal](https://daily.dev/sources/temporal)** · 23 min read · 0 upvotes · 0 comments ## Summary Temporal open sourced the entire ecosystem behind the ESP32-S3 hardware badges distributed to 2,000 attendees at their Replay conference. The repo includes C++ firmware, MicroPython bridge, KiCad hardware files, fabrication outputs, Doom port, OTA update tooling, and a Temporal-powered batch flashing system called Ignition. The post covers the engineering challenges of embedded development — memory constraints, resource ownership, partition layout, MessagePack vs JSON, and bridging C++ with MicroPython — as well as the process of curating a messy internal project into a clean open-source release that future contributors (human or AI) can navigate. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [I built 2,000 badges for Replay and I’m not sure I’ve slept since December](https://daily.dev/posts/i-built-2-000-badges-for-replay-and-i-m-not-sure-i-ve-slept-since-december-6zq7asu5z) · Temporal · 0 upvotes · 0 comments - [Ignition: Flashing 2,300 conference badges with Temporal](https://daily.dev/posts/ignition-flashing-2-300-conference-badges-with-temporal-4bgcem7oo) · Temporal · 0 upvotes · 0 comments --- Tags: [#iot](https://daily.dev/tags/iot), [#embedded](https://daily.dev/tags/embedded) [View this post on daily.dev](https://daily.dev/posts/how-we-turned-the-replay-keynote-surprise-into-an-open-source-embedded-playground-jvmlbu4zy)