I don't know, This is more or less how my company works (~150 people). It scales well, because even in a larger company there is a certain amount of intermingling between teams as developers change roles over time. For example, I know a lot of people in my company because I have moved across several different teams during my four year tenure. I just throw the people I want to hang out with at lunch on a Skype group chat. Sometimes they join and sometimes they do not.
On a different note, at my company, talking about work at lunch is pretty taboo unless the topic of the lunch was previously disclosed by the initiator to be work-related. Lunch is when we talk about all kinds of other bullshit and only talk about work if we're desperately spinning our wheels on something or want to vent.
On a different note, at my company, talking about work at lunch is pretty taboo unless the topic of the lunch was previously disclosed by the initiator to be work-related. Lunch is when we talk about all kinds of other bullshit and only talk about work if we're desperately spinning our wheels on something or want to vent.