Your Python script writes to Google Sheets on your laptop - then dies when you schedule it. This free one-pager covers the five errors behind most “it worked yesterday” cases:

1. 403 The caller does not have permission
2. 403 Google Sheets API has not been used in project … / disabled
3. invalid_grant: Token has been expired or revoked (the 7-day trap)
4. 429 Quota exceeded (and why batching beats retrying)
5. Could not deserialize key data / Invalid JWT Signature in CI

For each: the cause, the fix, and (for quotas) a copy-paste batch + backoff snippet.

Want the full system? The Starter Kit adds a 47-page guide, a tested Python toolkit (108 tests), a one-command Connection Doctor, GitHub Actions workflows and 3 Sheet templates.
https://whop.com/whop-0bab/python-google-sheets-running-on-autopilot-the-starter-kit/