I just shipped blueprintcalc.com — 12 home improvement calculators (paint, concrete, drywall, deck, mulch, tile, etc.) that compute material quantities AND output a full shopping list with prices and retailer links. I'd defaulted to Next.js for static-ish sites for years. This time I went with Astro and don't regret it. Here's the framework comparison and what actually mattered. The constraints Before picking a framework, I wrote down what the site had to do: ~95% of traffic will come from Google long-tail search. ("how much paint for 12x14 room", "concrete bag calculator 4 inch slab" — that kind of query.) SEO is everything. Lighthouse 95+ on mobile or I lose ranking. Google's Core Web Vitals are not optional for a content site competing with established players (Calculator.net, OmniCalculator). Calculator UI must be interactive — change inputs, see results update — without round-tripping to a server. No backend. No database. No auth. Every calculation is pure math on numeric inputs.…