---
title: 'How I found a missing change on my next.js site with PostHog'
date: 2024-09-02
excerpt: 'I tackle a significant drop in my newsletter subscribers. Join me as I dive into the data using PostHog, identify and fix critical errors, and ultimately switch from ConvertKit to Resend.'
tags: [typescript, nextjs, founder, posthog, video]
canonical: https://mikebifulco.com/posts/posthog-helped-me-find-a-bug
---
# How I found a missing change on my next.js site with PostHog

In this video, I discuss my recent efforts to improve the product analytics experience on my website. Over the past two weeks, I addressed a sign-up issue by switching to a new email service and implementing AB testing on my newsletter forms. I analyzed the results, but discovered a bug that prevented complete data collection. I walk through identifying the problem, show the fixes I made, and reset the experiment to gather accurate data. I also encourage viewers to check out the open-source code for my site and invite feedback and questions.

## See the code changes I made in this video

Code changes for this video are available in this pull request are available at [mbifulco/blog#840](https://github.com/mbifulco/blog/pull/840)

## Video Timestamps

00:00 Introduction and Recap
00:44 Analyzing AB Testing Results
02:32 Sponsorship Shoutout
03:01 Deep Dive into Data Analytics
05:41 Fixing Implementation Bugs
08:33 Resetting and Restarting the Experiment
10:28 Conclusion and Next Steps

## Part of the Fixing my conversion problem with PostHog series

- [Product Analytics for engineers: Debugging a conversion problem on my next.js site](https://mikebifulco.com/posts/debugging-a-conversion-problem-on-my-nextjs-site)
- [Fixing the sign-up problem on my site using PostHog Product analytics](https://mikebifulco.com/posts/fixing-my-conversion-problem)
- [Unlocking A/B Testing with PostHog: Improving Newsletter Signups](https://mikebifulco.com/posts/ab-testing-with-posthog-to-fix-conversions)
- [The results of my PostHog AB Test are in!](https://mikebifulco.com/posts/posthog-ab-test-results-are-in)

Full series: https://mikebifulco.com/series/fixing-my-conversion-problem-with-posthog

## More from mikebifulco.com

- [The results of my PostHog AB Test are in!](https://mikebifulco.com/posts/posthog-ab-test-results-are-in)
- [Fixing the sign-up problem on my site using PostHog Product analytics](https://mikebifulco.com/posts/fixing-my-conversion-problem)
- [Product Analytics for engineers: Debugging a conversion problem on my next.js site](https://mikebifulco.com/posts/debugging-a-conversion-problem-on-my-nextjs-site)

---

Written by Mike Bifulco. Originally published at https://mikebifulco.com/posts/posthog-helped-me-find-a-bug