Outdated or bloated web fonts — auto-detect, optimize, and open update PRs

Many commercial websites still ship outdated or over-privileged font files that inflate payloads and negatively affect Core Web Vitals, accessibility and perceived performance. The burden falls on front-end engineers, design-systems teams, agencies and platform operators who manage roughly 20 million commercial sites and currently spend an estimated $75/year per site on font tooling, delivery optimization or developer time. You could build a developer-centric service — a GitHub/GitLab app plus CLI and CI integrations — that scans repositories and live assets, auto-detects unused font faces and glyphs, suggests or converts to variable fonts and subsets, and opens automated PRs containing optimized font files, delivery headers, size deltas and regression screenshots. The product should include safe defaults, preview artifacts, license-aware rules and opt-out paths, plus a pay-as-you-scale pricing model that fits teams and agencies. This is an attractive market now because performance-first web strategies and Core Web Vitals are business priorities, variable fonts and subsetting are mature enough to produce 20–80% file-size reductions in many cases, and teams already accept Git-driven automation patterns (Dependabot-style) which lowers adoption friction. With an addressable market estimated at $15.0B (20M commercial sites × $75/year) there is clear willingness to spend on tooling that saves developer time and improves metrics tied to revenue. To stand out you must deliver deep workflow integrations (visual regression testing, license-aware rules, CI gates and canary rollouts) and be prepared to manage hard challenges around font licensing, subtle typographic regressions and cross-browser fallback behavior; getting those right would create a defensible, measurable product but will require careful UX, legal considerations and strong automated testing.