API latency plays a crucial role in performance and user experience. High latency frustrates users, reduces scalability, and increases infrastructure costs. This guide dives deep into causes, measurement, and optimization strategies for C# .NET APIs.

1. Understanding API Latency

API latency is the total time from a client sending a request to receiving a response — covering network transmission, server-side processing, and database interactions.

Types of latency:

Network latency — distance, bandwidth, congestion. Fix: CDNs.