Software Developer - Create a Legal Practice Management Software that is web based - similar to Mattero, Clio or Actionstep

I'm looking for an experienced software developer to create a custom legal practice management software that is web-based and similar to Mattero, Clio, or Actionstep. The software should include features like client management, document management, billing and invoicing, and trust accounting. The software needs to be compatible with specific third-party or other integrations, which I can discuss in more detail. I do not have a specific timeline for when this project needs to be completed, so the software developer can work at his or her own pace.