tl;dr:"A look at a group of software systems not well known to the public, which I call "Bank Python". Bank Python implementations are effectively proprietary forks of the entire Python ecosystem which are in use at many (but not all) of the biggest investment banks. Bank Python differs considerably from the common, or garden-variety Python that most people know and love (or hate)."
tl;dr:Suspicious of established cloud providers actually providing value for money, Cal compares virtual machine and object storage pricing amongst the main providers. Google, AWS, Azure came out to be more expensive than the others.