UX/UI designer for long-term collaboration

Hi! I'm looking for a UX/UI designer to strengthen my team. I need a person for proficient in Web App, Mobile App, and Website design. 

The second important requirement is an Intermediate+ English level. All our clients are from abroad, and the project requirements are in English. The overall process is much easier and faster when you can have a direct conversation with a client about small fixes, comments, etc.  Internally, we will speak Ukrainian, but for the first round of our collaboration, I'd like to have it in English.

If you have strong expertise in Web, Mobile Apps, and Website design, please apply with your portfolio.
Also, an important consideration is experience with User Flows and Wireframing,  so please send me examples of projects that went through these stages. I need to be confident that you can transcribe business logic into product architecture, not only create a beautiful UI.

I have an initial project I need your help with - a concept design for a Meeting scheduling application, which can be extended to the full app design.  All the materials and references I will drop in a chat. 

The budget set for the full app design (20-30 mobile screens)

Looking forward to receiving your applications and having a chat)