Server-side tagging, one year later
What actually changed after moving analytics tags to a server container, and what did not.
A year ago I moved the tags of a small e-commerce project from the browser to a server container. The promise was simple: fewer scripts on the page, better data quality and more control over what leaves the site.
Page weight did go down. Removing four vendor scripts saved about 180 KB of JavaScript on product pages, and Interaction to Next Paint improved noticeably on mid-range Android phones.
Data quality is a more nuanced story. Conversion counts became more stable, but mostly because the setup forced us to clean up duplicated events that had been firing for years. The container itself did not fix anything; the audit did.
The hidden cost is maintenance. A server container is one more piece of infrastructure with its own updates, logs and bills. For a small shop it is worth it only if someone actually looks at the data every week.
Next note: A short Core Web Vitals checklist for landing pages