Engineering Improvements to Prevent Service Disruptions

Twilio suffered a service disruption on Feb 26, 2021, which motivated the company to learn from the incident and make its services more resilient and reliable. The root cause of the disruption was an overload on a critical service that manages feature-enablement for many Twilio products. To address this issue, Twilio has implemented several technical improvements, including reconfiguring its Feature Service with more aggressive auto-scaling behavior and removing the service from critical paths to prevent service unavailability. Additionally, the company is making holistic changes to its engineering organization, such as completing an audit of production systems, improving deployment tooling, and introducing new standardized tooling, in order to mitigate the risk of similar issues across other services.