INTRO
Your UI is only as trustworthy as the API beneath it. You do not need to read RFCs — you need questions that reveal whether the backend will survive real tenants.
Contracts and errors
Ask how errors look to the client and whether status codes mean anything. Inconsistent `{ success: false }` with HTTP 200 is a smell.
Versioning matters once mobile or partners exist.
Payments and webhooks
If money moves, ask about idempotency keys and webhook retries. This is where silent double charges live.
I wrote a deeper reliability piece for engineers — founders can still demand the checklist.
Ops basics
Structured logs, rate limits on public routes, and a staging environment that mirrors auth. “We will add monitoring later” means you will debug blind.
Pair Next.js UI hosting with a clear API home — see Vercel vs VPS notes.
KEY TAKEAWAYS
“Error contracts are a product decision.”
- 02
Idempotency is mandatory near payments.
- 03
Staging + logs beat hope.
CONCLUSION
Closing thought
Reviewing an API design for your SaaS? Send the outline via Contact for a founder-level critique.
CONTINUE
Related pages
UP NEXT
SaaS Roles & RBAC on Next.js / MERN — Decide Early
How I design role-based access for multi-tenant SaaS on Next.js and Node — what to lock in week one, and what breaks if you wait.
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