"Crank gzip to level 9 for max compression"

"Crank gzip to level 9 for max compression"
On-the-fly level 9 burns CPU for ~2% smaller files vs level 5. On a 1-vCPU box that CPU is your whole budget.
Use gzip_comp_level 5; for dynamic responses. For static assets, don't compress per-request at all:
— pre-compress once: gzip_static on;
— ship .gz files built at deploy time
Level 9 only makes sense when it's done once, not every request. Better yet, add brotli static. Try it tonight.