How do you prepare a store for a traffic spike?

Test it before it happens. Compress the images, check the checkout under load, and confirm stock counts are accurate — those three cover most of what actually breaks.

The reasoning

Have a plan for the two failures that recur: overselling a line you cannot fulfil, and a payment gateway timing out under load. Both are much cheaper to prepare for than to explain.

What most people get wrong

Traffic spikes break the things that were nearly broken already — usually image weight and a checkout step nobody tested under load.

The customers won in that week are worth almost nothing unless something brings them back in January.

The preparation that matters happens in October. A store deciding its Black Friday plan in November is already reacting.

How an app changes it

This is the one week where owning a notification channel pays for the year — reaching last year’s buyers costs nothing per message.