API Integration: Eight Mistakes That Cause Trouble Later

1. No timeouts. Without a timeout, a slow provider can hold up your whole application. Set one on every outbound call.
2. Retrying blindly. Retrying a payment or a verification can charge twice. Use an idempotency key or reference ID so repeats are safe.
3. Treating success as certain. Handle errors, partial responses and rate limits. Show users a useful message, not a blank screen.
4. Ignoring webhooks. Polling wastes calls and misses events. Accept webhooks, verify the signature and process them from a queue.
5. Logging too little, or too much. Log request IDs, status and timing so you can trace failures. Mask personal data such as identity numbers.
6. Hard-coding the provider. If one vendor is wired through your whole code, switching is painful. Put a thin layer between your app and each provider.
7. No fallback or monitoring. Decide what happens when the provider is down, and alert on rising error rates instead of waiting for complaints.
8. Skipping documentation. Write what each call needs, returns and costs, so the next developer is not guessing.

A small checklist before going live

• Test with sandbox keys and with failing responses.
• Confirm rate limits and cost per call.
• Store secrets outside the code.
• Make sure retries cannot create duplicates.
• Set up an alert for failures.

Growable One was built around these ideas: one request format, test and live keys, idempotent requests, signed webhooks and provider routing with optional fallback. If you would rather not manage many vendor integrations yourself, that is what it is for.