Microsoft Dynamics NAV 2017 – OData/SOAP Web Services Expert (Purchase Cycle)

What we're building We're integrating programmatically with a NAV 2017 (v110) on-premise instance via its web services layer (ODataV4 + SOAP). We need an expert who knows NAV's data model cold — not someone who can click through the UI, but someone who understands what's happening at the table level and how to expose and call it via APIs. The specific problems 1. Purchase cycle data model — we need a clear, accurate map of how Tables 36/37/120/121/122/123 relate: PO → Receipt → Invoice → Posted Invoice. What fields link them (Order No., Receipt No., etc.), what's writable, and when. 2. ODataV4 web services — standard NAV pages don't expose all the fields we need (e.g. Order No. on purchase invoices). We need guidance on creating or extending Page objects to expose the right fields over OData. 3. SOAP + Codeunit 90 — we've registered Purch.-Post (Codeunit 90) as a SOAP web service. We need help understanding the WSDL method signatures and calling it correctly to trigger posting programmatically. 4. End-to-end posting flow — we want to replicate what a user does in NAV UI (create invoice from PO, link to receipt, post) entirely through API calls. Walk us through the correct sequence. Our stack - NAV 2017 v110, on-premise Windows Server - ODataV4 (port 7048) + SOAP (port 7047), NTLM auth - Go-based connector calling the APIs What we need from you - Documented purchase cycle flow at the table/field level - Working SOAP call to Codeunit 90 tested against our dev instance - Custom NAV Page (or guidance) to expose missing OData fields - 1–2 video calls to walk through findings and answer questions You're the right fit if you have - Built or extended NAV web services (OData and/or SOAP) before - Deep familiarity with NAV's purchase posting codeunits - Experience working directly in a NAV dev environment - Can work hands-on — we'll provide VPN access and credentials