It is always better to choose a medium-scale company that can focus on dot net solutions along with efficient net maintenance and has a team of skilled dot net programmers. Such a company should provide you a dedicated project manager with great business acumen.
Keep the following parameters in mind:
1. The company should have at least 7 - 9 years of experience in
.NET development and the use of entity framework
2. The company has a good portfolio in .NET and experience of
creating top desktop apps
3. Good strength of .NET developers