A technical SEO project gets signed off, the crawl comes back clean, and everyone moves on. Four months later organic traffic slides and nobody knows why.
Usually nothing dramatic happened. Someone shipped a new product template. A plugin updated and started injecting its own canonical tag. A staging robots.txt reached production. Each one is a normal day’s work for the team that did it, and none of them thought of it as an SEO change.
The short list I re-check every month
- Indexation count. Not the exact number — the direction. A sudden drop or a sudden jump both mean something changed.
- robots.txt and the noindex tags. One line, thirty seconds, and it has saved sites before.
- Canonicals on templated pages. Category, product, and paginated pages are where these go wrong quietly.
- Internal links to the money pages. New templates often stop linking where the old ones did.
- Page speed on the template, not the homepage. The homepage is the page everyone optimises and the page nobody converts on.
- Structured data validity. A plugin update can break it without changing anything visible.
- Server errors and redirect chains in the server log or the crawl, whichever you have.
That is a short pass, not a full audit. It is the difference between finding a problem the week it appears and finding it the quarter after.
Who should own it
Someone who will actually look. If that is a developer, give them the list and let them run it in their own tooling. If it is a marketer, the free tier of any crawler and Search Console will cover most of it. The worst arrangement is the one where everyone assumes it is someone else’s.
Technical SEO is not a phase of the project. It is maintenance, and it behaves like maintenance: cheap when it is regular, expensive when it is not.