GrowthBook A/B testing, an end-of-post CTA, and RSS feed additions

The Log#growthbook#ab-testing#nginx#astro#rss#personal-projects

A day spent adding a first GrowthBook-powered A/B test for a LinkedIn call-to-action, tightening up nginx rate-limit handling, and expanding an RSS feed reader with new sources.

Picked up a GrowthBook task that had hung and crashed in a previous session. Once that was sorted, I built out the site’s first real A/B test: an end-of-post call-to-action encouraging readers to connect on LinkedIn. That meant adding a new PostCta.astro component, wiring an experiments helper (src/lib/experiments.ts) to decide which variant a reader sees, and hooking it into the post layout.

On the infrastructure side, I added nginx config for GrowthBook and fixed the rate limiting on its /gb/ path — it was returning a 503 when the limit tripped, which reads as a server error, when a 429 (too many requests) is the more honest response.

Separately, I worked on an RSS reader project, adding a couple of new feeds (Google Cloud’s blog and Anthropic’s blog) and testing that the latest posts pulled through correctly. There was also some troubleshooting around a feed’s posts getting blocked before they’d show up in Discord — worked through that until it started coming through.

Otherwise a fairly typical day of small, contained project work.