How do you manage tracking pixels as your stack grows?

Curious how other founders handle this as they add more paid channels.

We were in the classic situation — gtag snippets hardcoded in _app.tsx, conversion events spread across components. Every time we needed to add a pixel or tweak a trigger, it was a PR and a deploy. Small thing, but it meant we were consistently under-instrumenting because the friction wasn't worth it for a quick experiment.

Recently moved everything to Google Tag Manager. Tracking now lives completely outside the codebase. New pixel is a 10-minute GTM config, not a deploy. Preview mode caught two misfiring conversion events we had no idea about. Load order is explicit. One place to audit what's firing and when.

The migration was about 2 hours and it's already paid for itself in time saved.

What I'm curious about: at what point did you move away from hardcoded scripts? Did you go GTM, or something else entirely? Some founders I've talked to swear by just keeping it in code for simplicity — wondering if there's a strong case for staying on raw gtag snippets at early stage.

We're building XreplyAI — AI social media tool for solo founders — and this came up as we started running paid acquisition across more channels.