What Replacing Calendly Taught Me About Trusting Open Source

cal.com, Calendly, zcal... booking SaaS isn't short on options, and most of them are genuinely decent. Free tiers cover the basics for a lot of freelancers. The catch: you're the product (nothing's really free), and your customer data lives somewhere you don't fully control and can't fully audit. A dysfunction I ran into on another SaaS tool was the trigger. Trusting a third-party service by default, just because it's widely used and billed monthly, doesn't always hold up. That episode was enough to make me reconsider every external service this site was relying on for functionality that's actually simple to self-host — and the booking widget, running on Calendly, was one of them. Nothing wrong with Calendly specifically. It worked fine. But structural friction had been building regardless: a recurring subscription for something as simple as displaying open slots and recording a choice, a hard dependency on a third party for a component with nothing exceptional about it technically, and customization capped by whatever the vendor exposes in settings — no way to go further if a need falls outside that box. On top of that, an integration constraint that mattered more than any of the above: the site runs on Astro, generating lightweight static pages by design, specifically to avoid the weight of third-party scripts and dependencies — the exact opposite of what embedding a SaaS widget implies. So: could a self-hosted alternative match the experience, without the monthly bill and without handing a core commercial function (people booking a call with me) to an external vendor? This is the write-up of that search, the codebase audit that came out of it, and the production rollout. The landscape Four self-hosted candidates stood out as genuinely comparable — not just UI skins sitting on top of someone else's API, not just internal-scheduling tools with the public-facing UX as an afterthought. CloudMeet — Svelte + TypeScript, deployed on Cloudflare Pages/Workers/D1, free-tie