It is relatively simple: strong Non-Disclosure Agreements (NDAs). One of my previous employers worked with Apple a couple of years ago to ensure the stability

It is relatively simple: strong Non-Disclosure Agreements (NDAs). One of my previous employers worked with Apple a couple of years ago to ensure the stability and security of Apple Arcade, and every employee, even the janitor, needed to sign an extensive NDA to ensure the secrecy of the project. We kept “the secret” for six (6) months or so, and at one point we almost lose the contract because someone mentioned the project’s name during a phone call, at home, while a family member was listening, and that person told someone else, and that someone apparently talked about it somewhere and Apple found out. Fortunately, the CEO managed to, somehow, keep the contract. Even inside Apple, they have to sign NDAs when you need to talk with a different team about a new product, project, feature, etc. I asked about it during recent interviews (January 2022) to join a team that is supposed to have massive cross-team work with the entire engineering organization.