- Incident: Discount Application Issues – Incident details

Postmortem: Discounts Temporarily Unavailable

Incident Summary

On 10th Feb 2026 5:01pm, discounts were temporarily unavailable during checkout. This action was taken to prevent a cascading impact on checkout and dependent services after an internal issue was detected in the discounts system. Disabling discounts ensured that checkout and other critical services continued to operate reliably without broader service disruption

Customer Impact

• Discount codes could not be applied for a limited period of time

• Checkout continued to work normally without discounts

• No orders failed or were lost during this window

What Happened

A database index used by the discounts system became corrupted, which caused discount evaluations to fail safety thresholds.

To protect the checkout experience, discounts were automatically disabled. This ensured that checkout remained stable while the issue was investigated and resolved.

Timeline

• T0: Internal alerts detected failures in the discounts system

• T0: Discounts automatically disabled to protect checkout and dependent services

• T0 + 2 minutes: Root cause identified as database index corruption

• T0 + 5 minutes: Index rebuild process started immediately

• T0 + ~1 hour: Index rebuild completed (extended due to large number of discounts)

• T0 + ~1 hour: Discounts re-enabled after system health verification

Resolution

• Discounts were temporarily turned off to maintain checkout reliability

• The affected database indexes were rebuilt

• Due to the large number (more than 1B+) of discounts, this process took approximately 1 hour

• Once the rebuild completed and systems were verified as healthy, discounts were restored

Prevention Going Forward

We are taking steps to reduce the likelihood and impact of similar issues by:

• Periodic monitoring around discount system and database index health

• Adding earlier alerts before safety thresholds are reached

• Optimising index maintenance and recovery procedures

We apologise for the inconvenience and appreciate your patience while we worked to restore full functionality.