Infrastructure Decisions · judgement tool

When should I add caching?

Repeated reads, expensive responses, DB strain and staleness tolerance decide it — not a requests-per-second number. Get a Not yet / Probably yes / Yes-priority verdict with every factor's provenance shown.

A judgement tool, not a tool ranking · thresholds are StackSays rules, not industry standards · official facts verified 2026-07-17 · share the URL to share your answers

How to read this: every factor below is tagged by where it comes from — official fact official/documented · calculation math on your inputs · StackSays rule our decision logic · StackSays estimate our judgement. The verdict cut-points are StackSays rules, not an industry threshold — there is no universal traffic number for these decisions.

Your situation

The recommendation updates as you answer. Share the URL to share it.

Same data read repeatedlyhot rows/queries served over and overResponses are expensive to computeheavy joins, aggregations, external fetchesRead-heavy workloadreads vastly outnumber writesLatency-sensitiveyou need consistently fast responsesDB is already a bottleneckprimary DB CPU/latency is climbingCan tolerate slightly stale dataseconds-to-minutes-old data is acceptable

Recommendation

Not yet

Based on the factors you set — 1 pushing toward adopting, 1 against.

Why it's leaning yes on these

+4 Staleness intolerance — You accept slightly stale data — caching is safe hereStackSays rule

Why it might be premature

-8 Repeated identical reads — Without repeated reads there's little to cache; a cache would mostly missStackSays rule

When to reassess

There is no universal 'requests/second' threshold. Re-evaluate when you actually observe repeated reads of the same data or the DB becoming the bottleneck — those are the real triggers, not a traffic number.

Minimal implementation

Cache the single hottest, most expensive, most-repeated response first (in-memory or a hosted Redis/KV). Set a short TTL and measure hit rate before caching more.

Risk of not doing it

Wasted compute and DB load on identical work; slower responses under load.

Cost & complexity once adopted

The cost is invalidation: a stale cache serves wrong data. Start with TTL-only (simplest) before event-based invalidation.

This is a judgement tool, not a leaderboard. The StackSays rule and StackSays estimate factors are StackSays logic and opinion; the official fact factors link to official sources below. No industry-standard threshold is implied — the answer is driven by the conditions you set.

Official facts cited

Source	Verified
Redis caching patterns (official)	2026-07-17

Only the factors tagged “official fact” rest on these sources; rules and estimates are StackSays logic and are labeled as such.

Next decision

Do I need Redis? →Do I need a CDN? →