Ask HN: Tips on managing rapid growth in your company?

A lot of the focus in HN seems to be about how to get an idea to the initial start-up phase. But what tips to people have about the awkward adolescence stage of a company; you've found a successful market for a product, you're hiring lots of new people, and you're looking to expand to new revenue streams. All sorts of challenges start to pop-up and I'm very curious how others handle them. Some examples:

* How do you handle organizing the company into effective teams and projects with competing goals of growing revenue in existing products and establishing newer (though riskier) product development efforts?

* As more people come in, how do you best get them started, introduce them to corporate culture?

* Longer term employees often have a serious lack of people management skills; as you bring in new people with those skills, how do you start to build a management strength in a company?

* When is the ideal time to establish performance reviews? They have their ups and downs; it seems like a good idea but the incentive structure has to be carefully thought through.

* New product development doesn't always work out in an unproven or competitive market (yes, we should all be following Steve Blank here). That said, there's a constant tension between driving existing revenues and establishing new revenue sources; and the shifts often have a lot of impact on what people are focusing on. Too many shifts can be disruptive to morale. What techniques can be used to balance these?

In general, I'd love to hear from other people who worked at places that went from a dozen or so employees to a couple hundred or more and have stories about what did and didn't work.