There's a class of internal tool that's perpetually under-built: the "look at this metric across our things" dashboard. Status of the deploy. Score of the SEO audit. Latency of the regional endpoints. We treat these like full-stack projects when they should be one Python file. This post walks through a 95-line single-file Flask dashboard I built to monitor SEO scores across a list of URLs. The same architecture works for any periodic JSON endpoint — score cards with deltas and sparklines, auto-refresh in the browser, runs anywhere Flask runs. You can use the live version right now without signing up for anything: https://seoscoreapi.com/demo/dashboard . And the entire source is one downloadable file: /downloads/dashboard.py . What we're building A page that: Polls a list of URLs every N minutes through an external API Renders one card per URL with score, grade, delta vs.…