Ask HN: How do you manage domain/product/technical knowledge in your company?

So I am one of the oldest engineers at this company. and the company grew significantly in the past year. I found myself in situations were everyone is asking for a few minutes to get an understanding of a feature or a piece of code or some service/integration and I find myself spending almost 60% of my time on such requests. So just curious how does different companies manage their internal product/tech knowledge and what does the knowledge distribution mechanism look like.