Lately, I’ve been digging into what actually slows down APIs. Here are a few bottlenecks that changed how I think about performance

Source: Dev.to

Key API Bottlenecks

• Not always the database; sometimes it’s how we call it – Sending multiple small requests instead of batching them adds network overhead.
• Connections are expensive – Rebuilding them on every request triggers repeated handshakes; reusing connections or employing a connection pool can eliminate this cost.
• Synchronous logging can slow you down – The system must wait after each write, introducing unnecessary latency.
• Repeated data fetching is often self‑inflicted – If the same response is requested repeatedly, caching at the appropriate layer removes unnecessary load.
• Payload size matters more than expected – Uncompressed JSON responses increase latency, especially at scale.
• Data format matters – JSON is convenient, but it isn’t always the most efficient choice compared to binary formats like Protobuf.