Understanding how your interface is used.
WHAT TO MEASURE
Calls per endpoint Calls per caller Error rates, by type Latency distribution Which versions are still used
WHY VERSION USAGE MATTERS
It tells you whether a deprecation can proceed.
WHAT ENDPOINT USAGE REVEALS
What callers actually need, against what you assumed.
WHAT TO LOOK FOR
Endpoints nobody calls Endpoints called far more than expected Callers making many calls for one outcome
WHAT THAT LAST PATTERN INDICATES
A missing endpoint that would serve them in one call.
WHY THAT IS VALUABLE
It is a direct improvement, identified from evidence.
WHAT ERROR PATTERNS REVEAL
Confusing parameters Documentation that is wrong Validation that is too strict
WHAT TO DO WITH A CALLER GENERATING MANY ERRORS
Contact them.
WHY
Their integration is broken, and they may not know.
WHAT TO TRACK OVER TIME
Growth per caller.
WHY
It indicates who matters, and who to consult before changes.
WHAT TO SHARE WITH CALLERS
Their own figures.
WHAT TO USE INTERNALLY
The data, when prioritising work.
WHAT TO AVOID
Collecting more than you need, particularly anything personal.
