Allegro/2018-08-01/hours
A marketing campaign DDoSed itself
Jan 2018Dec 2018
Poland's largest e-commerce site went down at the moment a campaign was driving peak traffic.
Lesson
Capacity you can't actually schedule isn't capacity. Test that autoscaling can really claim idle resources under real load.
Trigger
A marketing push caused a sudden traffic spike.
Mechanism
A misconfiguration in cluster resource management stopped new service instances from starting — so even with free hardware available, the platform couldn't scale to meet demand and fell over.
Interview lens
Capacity planning for known traffic events; verifying the scheduler can place instances under pressure.
Recurring patterns
