All Mango Markets code is open source
Is there an API for borrowing rates and/or funding? Not yet, but hopefully soon.
Is Mango Markets Code audited? Mango Markets code has been informally reviewed by Serum and Solana devs as well as the German white hat hacker team "Alles!"
How can I start working with Mango Markets? This Trello board **** (https://trello.com/b/tIj7K3FD/mango-development ) contains desired tasks from entry level to complete projects. Pick one you feel is a good fit and introduce yourself in dev-discussion channel. If things go well, congratulations you’re part of the Mango DAO! Also, Mango Labs is hiring: https://jobs.solana.com/companies/mango-labs