SaaS Rate Limiting and Quotas

Acknowledgement: Shared by Peter Bamuhigire, techguypeter.com, +256 784 464178.

Use When

• Designing per-tenant rate limits for a pooled or mixed-mode SaaS to prevent noisy-neighbor degradation.
• Adding plan-aware quotas (Pro gets 100k API calls/month; Enterprise gets unlimited).
• Implementing fair-queueing so a single heavy tenant doesn't starve the shared worker pool.
• Surfacing quota usage to the tenant (X-RateLimit-Remaining, in-product usage panel).
• Coordinating limits across multiple enforcement points (edge, gateway, service, DB pool, queue).
• Designing the response contract when limits are hit (status codes, headers, error body).

Do Not Use When

• The task is general application performance — use frontend-performance / backend perf skills.
• The task is the entitlements engine itself (what limits exist per plan) — use saas-entitlements-and-plan-gating. This skill is the enforcement runtime.
• The task is queue-based fair scheduling alone — use queue-specific skills.