Custom .NET CRM Development

I'm seeking a skilled .NET developer to work on my custom CRM. This project involves both modifying an existing system and building new features from scratch.

Key Requirements:
- Lead management
- Sales tracking
- Customer support management

Current Issues:
- Performance problems
- Missing features

Ideal Skills:
- Strong experience with .NET framework
- Proven track record in CRM development
- Ability to improve system performance
- Expertise in adding custom features

Please provide examples of similar work done and a timeline for completion.