I work for several very large telcos and I have been, so far, able to avoid both .NET and Java. Last time I wrote C# code was because Microsoft (then a client) demanded we run our application on a Windows server. I wrote a proxy that sat in front of the application (which ran on a Linux machine).
The kind of contracts you have is entirely dependent on your skill set and your network. The last time I was paid to write C# code was 8 years ago.
You need cooler friends ;-)