API works sometimes
Verdict
When an API works sometimes but fails at other times under the same client conditions, this behavior is unlikely to be caused by deterministic client-side logic.
If identical requests—without changes in payload, authentication, or environment—produce different outcomes, further client-side debugging has rapidly diminishing returns.
At this stage, consistency is no longer something the client can enforce.
Why This Happens
Intermittent success usually reflects variable execution paths beyond the client boundary, such as:
- Load-sensitive processing, where behavior changes under traffic
- Queue contention or backpressure inside the receiving system
- Regional routing differences or uneven dependency health
- Dynamic throttling or prioritization based on system state
These mechanisms are adaptive by design. They trade predictability for stability.
From the client’s perspective, the API appears unreliable. From the system’s perspective, it is behaving defensively.
Where You Can Stop
Once inconsistent outcomes are observed under stable client inputs, you can reasonably stop:
- Rewriting request payloads to chase determinism
- Adding client-side guards to mask variability
- Assuming intermittent success implies a hidden client bug
- Escalating retries or refactors in search of stability
Further progress depends on server-side guarantees or visibility, not client persistence.
What This Page Is Not
This page does not:
- Diagnose specific infrastructure failures
- Provide stabilization or retry strategies
- Explain platform-specific behavior
Its purpose is to clarify when inconsistency is structural—and when continued client-side effort becomes optional.
Intermittent success is not a signal to try harder. It is a signal to reassess boundaries.