Important (Please Read Before Bidding): Do NOT bid if you only have front-end or basic development experience We need someone with strong PHP backend + API integration experience Experience with integrations like QuickBooks, PandaDoc, Calendly (or similar APIs) is required Please share relevant past work or similar projects Generic copy-paste proposals will be ignored. To confirm you have read and understood the requirement, please start your proposal with: “I understand this is integration work inside an existing PHP CRM, not a new system.” Only experienced developers should apply. We need some integrations added inside our existing PHP CRM. We do not want any separate system or separate dashboard. Everything should work inside our current CRM only. Our main requirement is: QuickBooks From an existing client/prospect/deal inside our CRM, with one click we should be able to create the invoice in QuickBooks. If the customer does not already exist in QuickBooks, it should create the customer first, then generate the invoice. Invoice details/status should come back into our CRM. PandaDoc From the same client/prospect/deal inside CRM, with one click we should be able to send an agreement using our PandaDoc template. The document status should show in CRM such as sent, viewed, signed/completed. Signed PDF should be saved back into CRM. Booking / Calendly or similar We are flexible on the booking system side. It can be Calendly or another easy integration. Main purpose is that booking should connect with our CRM records. If staff books from an existing prospect, client details should auto-fill. If client books from website/public link, that data should come into the same CRM. Important: Existing PHP CRM only No separate portal Clean code Easy for our current developer to manage Proper API setup/settings Basic documentation/testing steps