Wallex CRM (UWP): Add Supplier Code Column with Validation & Sync to Products

We're looking for a developer to add a new "Supplier Code" capability to our Wallex CRM (a Windows UWP / C# application) and wire it through to our products. This is foundational work for upcoming supplier-side automations (auto-ordering via supplier APIs and contact channels), so please design with that downstream use in mind. The work is bundled into a single fixed-price contract of 80 USD, paid as one milestone upon completion. What needs to be done: 1) New "Supplier Code" column on the Suppliers screen: Add a new editable column named Supplier Code next to the existing Name column on the Suppliers list. Validation: the value must be 2 to 4 letters, A to Z only, with no digits, spaces, or symbols. The code must be unique per supplier (no two suppliers may share the same code). I will fill in the codes for existing suppliers manually once the column is in place. 2) Attach Supplier Code to existing products: Every existing product should automatically receive the Supplier Code of its linked supplier, via a one-time migration that backfills the database. The product SKU should reflect or include the Supplier Code per our SKU convention (we can confirm exact placement together if unclear). 3) Attach Supplier Code to newly uploaded products: Whenever a new product is uploaded or imported into the CRM, the Supplier Code of its supplier must be attached automatically, with no manual step. 4) Keep everything in sync automatically: If the supplier on a product changes, the product's Supplier Code (and SKU where applicable) must update automatically to match the new supplier. If a supplier's Supplier Code changes, the new code must propagate automatically to all products linked to that supplier. Deliverables: - Code changes committed to the existing Wallex CRM codebase. - A migration that backfills Supplier Code on all existing products. - Logic on product create/update and on supplier update to keep codes and SKUs in sync. - Light testing of each piece in our dev/staging environment before handover. - A short note when the column is ready so I can fill in the codes, plus a brief note per change explaining what was modified and where (file/function level). Timeline: roughly 3 to 5 business days. We'll have a short call to align on details before work begins. Revisions: up to 2 rounds of revisions within original scope, included. IP and Confidentiality: All code becomes our property upon final payment. Contractor agrees not to share or reuse the codebase or business logic. Ideal candidate: an intermediate C#/.NET developer comfortable with UWP desktop apps and database migrations. When applying, please briefly mention similar CRM or desktop application work you've done.