Front office and back office, on one platform
Most projects start from a business outgrowing the system it is on: an on-premises Dynamics CRM or GP server, Salesforce, HubSpot, or QuickBooks. The goal is the same each time. Sales and finance work from the same customers, orders, and invoices, with web orders, payments, and shipping flowing in on their own instead of being retyped from an inbox.
Two on-premises systems, one cutover
One recent client ran an on-premises Dynamics CRM and Dynamics GP, kept in sync by a connector and a lot of manual work. We moved both to Dynamics 365 Sales and Business Central in the same project: just over 2.1 million records, 79 of 247 legacy customizations rebuilt and the rest retired, and WooCommerce, PayPal, ShipEngine, and their survey platform connected. Three years later, the team that ran discovery still supports the system.