This is really a tale of two customers – both reasonably large and successful companies who’ve been using VS for many years. Both had reached out to us with saying they were having problems with sluggishness and stability when dealing with solution files containing 100s of projects and millions of files. One customer, for example, had a solution file with 500 projects (all .NET), which was making VS hang and crash from anywhere within five to 60 minutes of opening a solution. Another customer had a solution file with 200 projects (mostly .NET, but a handful of C++ projects). Though this project would load successfully, it would consuming a lot of CPU cycles, causing the IDE to be very sluggish while editing code, and the customer also experienced random crashes. On the surface, these might look like very related issues. But they weren’t. As we talked with the customers and debugged their solutions, it became clear that the root causes were pretty different.