The Peak-Season Prep Checklist: What to Finish 30 Days Before the Big Sale

For the brands that explode with orders on Double 11, the outcome was actually decided a month earlier. The cruelest thing about a major sale event is that it amplifies every weakness in your systems and operations at once — problems invisible at a few dozen orders a day all blow up together at several hundred or a thousand. The site buckles, inventory doesn't reconcile, the payment gateway hits its limit, customer service drowns — every one of them a debt you didn't fix because it was "good enough" in normal times.

Our own e-commerce store runs the big sale seasons every year, and the prep checklist gets longer annually, because every year teaches us a new lesson. Here's the checklist, laid out on a timeline: what you should have finished in the month before launch.

D-30: systems and infrastructure

• Traffic forecasting and load testing. Take the peak traffic from last year's event (or your most recent campaign), multiply by this year's expected growth, and load-test the checkout flow — not the homepage, the checkout flow. A dead homepage is embarrassing; a dead checkout loses money.
• Confirm your payment processing limits. This is the most easily forgotten item and the most fatal when it goes wrong: your payment provider's credit-card acquiring limit has a ceiling. Blow through the daily or monthly cap and every subsequent customer simply cannot pay. Estimate the event's revenue and apply for a higher limit with your payment provider in advance — with providers like ECPay, these applications take processing time, so don't leave it to the final week.
• Check your e-invoice number allocation. Taiwan's government e-invoicing assigns invoice numbers in allocated blocks; a surge in event orders can exhaust your allocation and invoicing fails outright. Confirm the remaining quota and apply for additional blocks early if needed.
• Schedule and test campaigns in advance. Our campaign engine supports pre-launch countdowns and automatic on/off scheduling; every event is configured in the back office beforehand: launch time, which bundles, end time, automatic reversion to regular prices afterward. Never plan to "manually change prices at midnight on the day" — sleep-deprived manual price edits are a perennial cause of event-day incidents. Once configured, run the entire timeline end to end in a test environment.

D-21: inventory and supply chain

• Full stocktake. The gap between book inventory and physical inventory is a minor annoyance in normal times and an overselling incident during a sale. Finish the count before restocking arrives so your baseline is clean.
• Stock up on hero products — and script the stockout. Stock according to the campaign's featured list, and prepare a plan B: which item substitutes when something sells out, and when the page switches to pre-order or comes down. Selling out during an event is no shame; continuing to take orders after selling out is a disaster.
• Packing supplies and event notices. Boxes, cushioning, thank-you cards at 1.5× projected order volume. Carriers get congested during major sales, so adjust your stated delivery times on product pages and notifications in advance — don't make customer service apologize for your overpromising.

D-14: customer service and staffing

• Support volume scales in proportion to order volume, concentrated on "when will it ship." Update your SOPs and canned replies to event versions (delivery times, campaign rules, gift terms), update the FAQ page and LINE keyword replies in sync, and make self-service handle whatever it can.
• Schedule shifts to cover the 72 hours after launch and the shipping peak — those two windows are the message tsunamis. Train any temporary helpers on the SOP at least a week ahead — temps without an SOP only generate second-round complaints.
• Announce the cutoff rules for order changes up front: address changes, store changes, order merging — state the deadlines clearly and you'll deflect an entire category of messages.

D-7: marketing and final checks

• Warm-up begins: countdown page live, LINE segment and SMS teaser schedules configured, all ad creatives and audiences approved and standing by. Ad-platform review queues jam up during major sales — submitting creatives at the deadline is suicide.
• One full end-to-end rehearsal: walk the entire flow in the production environment — place an order, pay, issue the e-invoice, generate the shipping slip, send notifications. All-green in staging doesn't mean production works; that's a conviction we bought with our first bad order.
• Monitoring and alerts live: order volume, payment failure rate, site response time, with anomaly alerts configured. On launch night you should be watching a dashboard, not refreshing the admin panel.

Big sale seasons don't reward the hardest-working team — only the best-prepared one. On the day itself, all you can do is watch the system run. So the you of one month earlier decides how calm the you of launch day gets to be.

As for how to design the event's discount structure and defend your margins, that's its own discipline — we cover it in designing a Double 11 campaign. And if reading this checklist you realize terms like "automatic scheduling" and "payment limits" are foreign to your current system, then the best investment before this year's season may be the system itself — see our e-commerce development services. Preparation favors the early.