Hi, I work in infrastructure at Stripe and I&#x27;m happy to provide more insight. Several threads here have commented on our tooling and processes around index changes. I can give a bit more detail about how that works.<p>We have a library that allows us to describe expected schemas and expected indexes in application code. When application developers add or remove expected indexes in application code, an automated task turns these into alerts to database operators to run pre-defined tools that handle index operations.<p>In this situation, an application developer didn&#x27;t add a new index description or remove an index description, but rather modified an existing index description. Our automated tooling erroneously handled this particular change and interpreted it not as a single intention but instead encoded it as two separate operations (an addition and a removal).<p>Developers describe indices directly in the relevant application&#x2F;model code to ensure we always have the right indices available -- and in part to help avoid situations like this. In addition, the tooling for adding and removing indexes in production is restricted to a smaller set of people, both for security and to provide an additional layer of review (also to help prevent situations like this). Unfortunately, because of the bug above, the intent was not accurately communicated. The operator saw two operations, not obviously linked to each other, among several other alerts, and, well, the result followed.<p>There are some pretty obvious areas for tooling and process improvements here. We&#x27;ve been investigating them over the last few days. For non-urgent remediations, we have a custom of waiting at least a week after an incident before conducting a full postmortem and determining remediations. This gives us time to cool down after an incident and think clearly about our remediations for the long-term. We&#x27;ll be having these in-depth discussions, and making decisions about the future of our tooling and processes, over the next week.