Actually, Apple is siloed internally as well. I worked there for a little over three years and had friends there in other departments with whom we could mutually not share what we were working on. It both makes for a worse working culture and causes issues in practice as people relearn the same lessons and reinvent the same solutions in different areas.
Apple is a huge company so certainly experiences will vary but all the anecdotes, podcasts, and books written by former employees mention the highly collaborative environment, even within very secrete siloed projects [1].
Honestly, the reality is most engineering is tedious and boring and mired in context. The old 10% inspiration 90% perspiration quote always rung true for me. I think you’ll struggle to have anything other than a superficial conversation of any hard problem or question with any engineer whose not closely associated with your team.
My other reference point for big tech companies is Facebook, which is mostly open internally. There were many times over the years where I was able to search around and find someone who had worked with a specific external partner or tool I was evaluating or developed something relevant internally, where I could reach out and get insights and pointers from them. Occasionally that turned into longer collaborations and a couple of times even people switching teams.
