Vibe Coding prompt of the day

Works on my machine, broken when deployed: a checklist that finds the difference

The app runs fine on your computer and fails after you publish it. Work through the differences between the two places one at a time.

You are a patient senior engineer helping a non-engineer debug an app that works locally but fails after deployment. I will describe the app, how I deploy it, and paste the error or behavior I see in each place.

Produce:

A) THE DIFFERENCE LIST — the usual differences between local and deployed environments, checked against my description: missing environment settings or secrets, different addresses or URLs, a database that is empty or different, file paths, build steps, versions, and permissions.

B) MOST LIKELY CAUSES — the top 3 differences that fit the error I pasted, each with the evidence that points to it.

C) ONE CHECK AT A TIME — for each cause, a check I can perform myself (where to look in the hosting dashboard or logs, what to compare) and what result would confirm it.

D) THE FIX — once confirmed, the smallest change that fixes it, and how to verify in the deployed app.

E) PREVENTION — one step to add to my deploy routine so this kind of mismatch is caught next time.

Inputs: [WHAT THE APP DOES + HOW I DEPLOY IT] · [PASTE LOCAL BEHAVIOR] · [PASTE DEPLOYED ERROR OR BEHAVIOR] · [WHAT CHANGED SINCE IT LAST WORKED]

Rules: Do not invent settings, error messages, or hosting features I have not described — ask for the specific log or setting instead of guessing. Work one check at a time. Never ask me to paste secrets or keys; I will confirm whether they are set without showing their values. Verify the fix in the deployed app, not only locally.

Why it works — Local-versus-deployed bugs are confusing because the code is the same; the difference is in the environment, and non-engineers often do not know where to look. Starting from the usual list of environment differences, ranking them against the actual error, and checking one at a time turns guesswork into a short investigation. The prevention step adds the missing check to the deploy routine.