A few years ago, many of the Y Combinator B2B startups wrote tools for the developers in other companies--metrics software, deployment software, monitoring software, build software, development frameworks, etc. The startups would want to meet with the technology people at companies to sell their service.

There's been a significant shift--lots of the YC B2B startups are now building software to help non-technical people in companies (usually large ones with a primary business that is not writing software) avoid their internal IT department when they need software to help them get something done. It's faster and easier. So now the startups are trying to avoid the developers at the other company (so they don't get blocked) and sell to the person who is waiting in the internal development queue.

It will be interesting to see how far this trend goes, and something to keep in mind if you’re starting a new company.