If you want your Black Friday to work, start building it today. Not in November, when every change is risky and your developer is fully booked.
The setup checklist
Start with discount codes, and make sure every one has a real start and end date. Codes that never expire are how a store bleeds margin into December and beyond.
Next, decide which products are actually going on offer and put them in a dedicated category, something like black-friday-deal. Naming it generically means you reuse the same structure next year instead of rebuilding it. Then set up global site rules if you want a discount applied across the whole store, rather than editing products one at a time.
Finally, prepare the offer toolbar or banner so the promotion is visible without a customer having to hunt for it. Every one of these is a small build task that is calm in September and terrifying on the day.
Why the timing is the whole point
Peak weekend is not when you experiment. It is when your existing build gets stress-tested at a load no staging environment reproduces, which is exactly why Black Friday is the real test of your build. Changes made under that pressure are how a good year turns into a black day.
The same logic applies to bigger swings. Replatforming or rebuilding during peak is the single worst decision available, which is the whole story behind the ten-minute call that found a Black Friday disaster.
What to harden while you are in there
Do the infrastructure work in the same pass. Server response decides whether the checkout holds when traffic triples, which is why time to first byte deserves more attention than image compression. And run a security check, because malware activity climbs going into the season and the stores that get hit rarely see it coming.
None of this is clever. It is just done early, which is the entire argument for getting the foundation right.
If you want your store audited before peak rather than during it, book a call.