Definition
Exponential backoff is a retry strategy that doubles the wait time after each failed attempt. If the first retry waits 1 second, the second waits 2, the third waits 4, the fourth waits 8, and so on - each retry waits twice as long as the previous. The effect is that a transient blip gets retried quickly, but a sustained outage stops generating a retry storm that could prolong the outage.
Production implementations add jitter (a random offset to each wait time) to prevent the thundering-herd problem where many clients retry in lockstep. They also cap the maximum wait time ("after 10 retries, don't wait longer than an hour") and have a final retry count beyond which the operation is declared failed.
How SheetLinkWP relates to Exponential Backoff
SheetLink Forms' retry queue uses exponential backoff with jitter: 1 minute, 5 minutes, 15 minutes, 1 hour, 6 hours, each plus or minus 10% random jitter. After 5 failed attempts, the submission moves to the dead-letter list in SheetLink > Tools > Retry Queue. This schedule has proven to cover almost all transient Google Sheets outages (which are typically under an hour) while not generating enough retry traffic to accidentally DoS our own integration.