SAN FRANCISCO — In-house startup lawyers say they love the freedom of their job. They love the collaboration, the decision-making and the direct impact they have on their companies. But what happens when those early-stage companies sell to corporations with billions of dollars in revenue, hundreds of attorneys and layers of bureaucracy? For many startup lawyers, it means goodbye freedom, goodbye direct impact, and sometimes, goodbye job.

Tom Kennedy, the former general counsel at BigFix Inc., said he knew what was coming when his company sold to IBM Corp. in 2010.