Catching media and caption errors before a post enters the queue

Tools of the trade
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  1. Start with the intended destinations and publishing route. Record which account receives each post and whether the final handoff uses an API, browser, or device workflow. That route determines which fields and media variants the preflight can actually check. A generic “valid image” result is not enough if the next step expects a different file or caption field.

  2. Check the asset assigned to each destination. Suppose one product photo is going to Instagram and LinkedIn. The draft might use a portrait crop for Instagram and a landscape crop for LinkedIn. Before either job enters the queue, confirm that both files exist, can be opened, and match the format, size, and dimensions configured for their respective publishing steps. Report “LinkedIn landscape file missing,” not just “media error.”

  3. Build and preview the final payload. Apply the destination-specific caption, replace any placeholders, and show the exact text and file that will be handed to each publisher. This catches a caption that still says {product_name}, a missing link, or a crop that cuts off the subject. Preview the submitted version, not the shared draft.

  4. Block only the affected job and log the failed check. Keep the destination, draft ID, check name, and failure detail together so someone can fix the input without reconstructing the whole flow. For a first version, a pass/fail result and a readable error are enough; more elaborate rules can wait until the logs show recurring failures.

Which preflight check has prevented the most avoidable publishing failures in your workflow?

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Previewing the submitted version rather than the shared draft is the right boundary. For example, when preflight passes, queue the exact caption text and an immutable copy of the media file, then have the publisher send those—not reread the draft. A later edit can then create a new job, but cannot change what the validated job publishes.