How would you apply rate limiting to an ASP.NET Core API without breaking legitimate clients?

Apply rate limiting without breaking real clients

Design and debug rate limiting while protecting the API without blocking legitimate users and integrations.

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Rate limiting protects the API by limiting how many requests a caller can make in a time window. I would choose the key carefully: user, tenant, client app, API key, or IP depending on the endpoint. The API should return 429 Too Many Requests with useful retry information. The goal is to reduce abuse or overload without punishing normal clients.

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abuse protection, client fairness, rollout safety, distributed enforcement, and operational behavior

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Design and debug rate limiting while protecting the API without blocking legitimate users and integrations. It matters in real backend work because the team needs observability, ownership, and rollback room to recover without guessing. The practical angle is abuse protection, client fairness, rollout safety, distributed enforcement, and operational behavior, tied to a concrete production decision.
Rate limiting protects the API by limiting how many requests a caller can make in a time window. I would choose the key carefully: user, tenant, client app, API key, or IP depending on the endpoint. The API should return 429 Too Many Requests with useful retry information. The goal is to reduce abuse or overload without punishing normal clients.
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I would start by observing real traffic before enforcing limits. For example, I might log request rates per tenant and endpoint, then roll out limits gradually. The trade-off is that strict limits protect the system but can break batch jobs, mobile clients, NATed users, or integrations. Different endpoints often need different limits, and clients need clear expectations.

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Rate limiting only by IP for authenticated APIs
Rolling out limits without observing traffic
Returning 403 or 500 instead of 429
Applying one global limit to all endpoints
Ignoring batch clients

How would you apply rate limiting to an ASP.NET Core API without breaking legitimate clients?

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