The technical SEO checklist developers actually own
Content strategy is somebody else's job. These items are yours.
One title, one H1, one intent
Keep titles under about 60 characters so they are not truncated in results, put the primary keyword near the front, and make sure every page has exactly one H1 that matches what the page is about.
Descriptions are click-through copy
Around 150 characters, written for a human, describing the specific value of that page. Duplicated descriptions across a template are worse than none.
Canonicals
Every indexable page should declare a canonical URL. Normalise the host case, force one protocol, decide on trailing slashes once, and strip tracking parameters.
Structured data
Add JSON-LD that matches what is visibly on the page: `SoftwareApplication` for a tool, `FAQPage` when you actually show the questions, `BreadcrumbList` when you render breadcrumbs. Marking up content the user cannot see is a policy violation.
robots.txt and sitemaps
robots.txt controls crawling, not indexing. Use `noindex` when you want a page kept out of results. Reference the sitemap from robots.txt, keep it to canonical URLs only, and regenerate it as part of the build.
Then measure
Ship the checklist first — it is cheap and it compounds.