Black Friday 2026 falls on November 27. A slow site, overselling stock or a wrong discount price on campaign day can cost far more than a day of sales. This post is a 15-item checklist for reviewing the technical side of your online store before the campaign, with short notes on why each item matters.
Short answer: 5 critical checks before Black Friday
The five most critical infrastructure checks before Black Friday are: a load test against campaign traffic, tying stock and ERP sync to a single source of truth, verifying campaign prices and the pre-discount price rule, testing payment and shipping integrations end to end, and having monitoring and a rollback plan for campaign day. The list below expands these five areas into 15 items.
The 15-item Black Friday infrastructure checklist
| # | Check | Owner | Status |
|---|---|---|---|
| 1 | Load test for product list, product page, cart and checkout | Development / IT | ☐ |
| 2 | Review cache and CDN settings for campaign pages | Development / IT | ☐ |
| 3 | Check image sizes and page speed (especially on mobile) | Development / IT | ☐ |
| 4 | Backups and a rollback plan in case of failure | Development / IT | ☐ |
| 5 | Define the direction and frequency of stock sync (ERP ↔ site) | Development + Warehouse | ☐ |
| 6 | Stock buffer for campaign products (prevent overselling) | Operations | ☐ |
| 7 | Verify campaign prices are identical in the ERP and on the site | E-commerce + Accounting | ☐ |
| 8 | Check the pre-discount price follows the rule (lowest price of the last 30 days) | E-commerce | ☐ |
| 9 | Test coupon and discount rules for conflicts | E-commerce | ☐ |
| 10 | Test payment provider limits and the 3D Secure flow | Development + Finance | ☐ |
| 11 | Test the order queue, email and SMS notifications | Development / IT | ☐ |
| 12 | Shipping integration and daily capacity (labels, tracking numbers) | Operations | ☐ |
| 13 | Monitoring and alerts: error rate, response time, payment failure rate | Development / IT | ☐ |
| 14 | Emergency plan and on-call list (who is called, in what order) | Whole team | ☐ |
| 15 | Customer support readiness: FAQ, live chat, returns and exchange copy | Customer service | ☐ |
Servers and speed: can your site handle campaign traffic?
When and how should a load test run?
A load test tries out in advance what happens when many visitors use the site at the same time. Test the product list, product page, cart and checkout steps; k6, Apache JMeter and Gatling are commonly used tools. Some e-commerce guides recommend testing at least 4-6 weeks before the campaign; even if time is short, a brief test is better than none. If possible, work in a production-like environment and use the payment provider's test mode.
How much traffic should I expect?
Use your own history as the baseline. As a directional indicator, a report from a US-based e-commerce platform says order volume on Black Friday can reach roughly 3.7 times normal days. That figure belongs to the US market and that platform's data; it is not an exact rate for Türkiye, so it is healthier to set a test target of several times your own traffic on last year's campaign day.
Why do caching and images matter?
On campaign day most of the load comes from frequently opened pages. Caching list and campaign pages, reducing image sizes and using a CDN lightens the server's work. Cart and checkout pages are personal, so they should not be cached.
Stock and ERP sync
In which direction and how often should stock sync?
First decide who the "single source of truth" is: usually stock lives in the ERP and the site reads from it. If both sides write stock, conflicts on Black Friday are unavoidable. For campaign products, event-based updates (at order time) are safer than batch sync; if you use batch sync, shorten the interval for campaign day. There is no single "right" number of minutes; it depends on your order rate (this is general good practice, not a standard).
How do I prevent overselling?
Set aside part of the stock for campaign products as a buffer and reserve stock when an item is added to the cart. Stock should be checked again when the order arrives, and a sold-out product should be updated to "out of stock" within seconds.
Campaign rules and the pricing engine
How does a campaign price reach the ERP?
Define the campaign price in the ERP as well as on the site, and run a check that compares the two. Verify with a few test orders what price an order from the site arrives at in the ERP and how the coupon and discount appear on the invoice; accounting differences should be noticed before the campaign, not after.
How should the pre-discount price be shown?
Under the change to the Price Tag Regulation (Fiyat Etiketi Yönetmeliği) published in the Official Gazette on February 18, 2022, the price before a discount is determined as the lowest price applied in the 30 days before the discount, and the burden of proof is on the seller. According to news reports on the Ministry's July 2025 warnings, advertisements are expected to state the previous price, the validity period of the price and any stock limit. Check your last 30 days of price history before entering campaign prices; for the current text of the regulation see the Ministry of Trade announcements and the Official Gazette.
What happens if coupons and discounts conflict?
Set rules in advance for whether a cart discount, a product discount and a coupon can be combined, and test a few combinations. Conflicting rules can accidentally produce a "0 TL" or loss-making sale.
Payment, shipping and the order queue
What should be tested on the payment side?
Test the payment provider's transaction limits, the 3D Secure flow and failed-payment scenarios. Know in advance what the customer will see if the payment provider slows down on campaign day and whether the cart is preserved.
Are shipping and order notifications ready?
Order queuing, email and SMS notifications and shipping label generation should all run at the same speed. Keep the courier's daily capacity and post-campaign delivery times realistic in the text you show customers.
Campaign-day monitoring and the emergency plan
What if the site goes down on Black Friday?
There should be a predefined plan: who receives the alert, in what order people are called, and which backup or previous version you roll back to. Prepare a simple "maintenance / heavy traffic" page and a social media announcement. Do not release new features on campaign day; freeze code changes before the campaign.
Which indicators should I watch?
Response time, error rate, payment failure rate, cart abandonment rate and stock alerts. Set thresholds for these indicators and alert the responsible person when a threshold is crossed.
Next step
If some items on the checklist come out missing in your setup, take a look at our e-commerce service for improving your store or connecting your systems (ERP, payment, shipping) and at our support and maintenance service for post-campaign upkeep, or get in touch.
Frequently Asked Questions
<details> <summary>What if the site goes down on Black Friday?</summary>Switch to the predefined emergency plan: the person who receives the alert, a rollback to a backup or previous version, and an announcement page for customers should be ready. Not releasing new code on campaign day reduces this risk.
</details><details> <summary>How many minutes should stock sync take?</summary>There is no single figure for everyone. For campaign products, updating stock at order time is the safest; if you use batch sync, shorten the interval according to your order rate and keep a stock buffer.
</details><details> <summary>How does the campaign price reach the ERP?</summary>Define the campaign price in the ERP too and compare it with the price on the site. Use a few test orders to verify the amount at which the discount and coupon arrive in the ERP and on the invoice.
</details><details> <summary>When should a load test run?</summary>Ideally weeks before the campaign; some guides recommend at least 4-6 weeks. If time is short, a brief pre-campaign test is better than none.
</details><details> <summary>Which price should be shown as the pre-discount price?</summary>Under the regulation, the pre-discount price is the lowest price applied in the 30 days before the discount, and the burden of proof is on the seller. Check the Ministry of Trade announcements for the current text.
</details>Sources: Price Tag Regulation amendment (Bloomberg HT), Discount sales advertising rules, July 2025 (Yeni Asır), Black Friday 2026 data (ShipperHQ), Black Friday checklist 2026 (Website Builder Expert)