TikTok's Events API is younger than Meta's, which is a polite way of saying you should expect a few rough edges. Here are the things we keep coming back to.

1. Treat your tagging URL like product infrastructure. It is not a marketing toy. Put it on the same uptime monitoring as your checkout.
2. Use a custom domain from day one. Switching later is annoying and almost always loses some history.
3. Hash PII before it leaves your server. SHA-256 the email, normalise it first, and never log the plaintext.
4. Keep a written event taxonomy. It does not need to be elegant. It does need to exist somewhere people can find it.
5. Version your container changes. GTM gives you versions for free. Use them. Future-you will be grateful.
6. Test in preview mode for everything. Including the things you are sure work. Especially those.
7. Reconcile with backend data weekly. A small drift is normal. A growing drift is a fire.
8. Send a test event before you celebrate. TikTok's test-event tooling is genuinely useful and saves you from arguing with reporting later.

None of these are revolutionary. They are the boring habits that separate teams who trust their data from teams who argue about it. A weekend of attentive setup buys you a measurable lift in TikTok-attributed performance.