Full-stack developer

Hello, I am looking for a full-stack developer for a one-time mission on Velya, a SaaS application that automates replies to Instagram messages for aesthetic clinics. We have a bug: some patient requests are being saved without a phone number, or sometimes with the clinic’s phone number. The AI does not systematically ask for the phone number before saving the request. Could you please reply with: 1. What you think the possible causes of the issue could be. 2. How you would audit the system to identify the exact source of the issue. 3. What you would fix to prevent a request from being created without a real patient phone number. 4. The estimated time needed for the audit. 5. The estimated time needed for the correction. 6. Your estimated budget for this one-time mission. 7. What access you would need to get started. The goal is not to rebuild the whole application, but to fix this issue in a clean, secure, and documented way.