How to find a slow endpoint in an API — which part of the code is slowing down?

To find a slow endpoint and determine which part of the code is causing the slowdown, profiling and timing logs are used.

1. Add time measurements at the beginning and end of request processing to understand the overall delay.
2. Use profilers, such as pprof in Go, to get detailed information about function execution times.
3. Log the execution time of key operations within the handler (e.g., database queries, calls to external services).

Example of using pprof:

import (
    "net/http"
    _ "net/http/pprof"
)

func main() {
    go func() {
        log.Println(http.ListenAndServe("localhost:6060", nil))
    }()
    // rest of the server code
}

After starting, you can open http://localhost:6060/debug/pprof/ and analyze the profiles.

This approach helps localize bottlenecks and optimize specific parts of the code.