Creating user account creation process

We already have User Account creation process. We want to refine it. Such as adding/improving e-mail and mobile number verification. Improving profile page (like LinkedIn profile of Work-experience, Academics, Certifications etc.) for users. Integrating Payment Gateway (Cashfree) for payout method verification.
At first we would like to have a Zoom call with developer, to explain the requirements to developer and to answer any queries. Based on that we expect detailed solutioning from developer. Only after freezing solution, time and price, we will proceed with implementation.