Usually the larger the company and the more mission critical the product: the worse the implementation.
Twitch source code (which, I guess counts as Amazon already), Disney leaks- and my own experience working with very large companies. (Nokia, Ubisoft, Facebook, Activision/Blizzard).
Your comment tells me you have never read any of AWS many documents about how they engineer their components. They put an huge amount of effort into it. AWS is much more reliable that Azure. They have built the largest and most reliable storage system in the world with S3. AWS has stated that some customers have S3 buckets using over 1 million hard drives. Netflix relies heavily on AWS for its streaming services. Lyft runs its ride-sharing platform on AWS. Capital One migrated its entire infrastructure to AWS. Slack relies on AWS for its messaging platform. GE utilizes AWS for industrial IoT (Internet of Things) solutions, predictive maintenance, and data analytics. Twitch streams video to 31 million viewers from AWS.
AWS is an industry leader in using formal methods and automated reasoning to prove the security and reliability of critical software and detect insecure configurations
And in the case of AWS it is someone else's extremely well designed and managed computer and network.