Cut TTFB to a 200ms budget

Cut TTFB to a 200ms budget
TTFB (time to first byte = server + network before HTML starts) hides 4 stackable costs. Audit them in order, largest first.

— Redirects: each hop adds 80-300ms. Target 0. curl -sI -w '%{num_redirects}' your URL.
— DNS + connect + TLS: should sum under 120ms on a warm CDN. Cold = move origin closer.
— Server think time: log it. Over 200ms means query/cache work, not network.
— Cache HIT ratio: aim p75 > 90% edge HITs; a MISS often triples TTFB.

Before | After on one fix (kill a 302): 540ms -> 410ms.

Takeaway: a healthy field TTFB at p75 is under 800ms; lab target 200ms.