[nvartolomei]

According to public information, AWS uses both and not only. AWS wrote a paper on the topic with some details about their applications of formal methods^1. AWS is a large org though, it would be hard to generalise or reduce their approach to any single method.

1: https://www.amazon.science/publications/using-lightweight-fo...

Later add: I believe P creator is employed by AWS at this moment.

[steepben]

Ankush has moved on to Snowflake now, but he was previously at AWS.