I have one client that pays me $10k/mo, How to find similar customers?

I run a software development agency, and I help build software, be it a need for a dedicated software developers team or building MVP at an affordable cost. I'm working with one of the clients who pay me over $10K+ a month, and I have been working for over 6 months with the client. I'm looking for the best options to find similar clients in the same industry as I already have clear insights about the business domain and a solid case study on how it helps businesses save time and money with the product we built. How do you think I could reach out to similar clients? Need suggestion.