More than 10,000 companies depend on Workday for HR, finance and payroll, and it pulls in almost $10 billion a year in revenue. Employees hate the system because every process—comp cycles, reporting, promotions—feels like manual drudgery. Yet customer churn hovers near zero not because people love it but because ripping it out means untangling hundreds of integrations, retraining admins and rebuilding every workflow from scratch. Workday’s real moat lives outside its code. Its proprietary configuration tools—Workday Studio, BIRT reports and custom expression syntax—lock in a cadre of 10,500 certified consultants at firms like Accenture, Deloitte and PwC. Implementations run 6–18 months and cost $300K–$1M, matching software fees. Multiyear contracts and the sheer complexity of moving every data feed keep customers stuck. Last year Workday tried to fight back with AI under its Illuminate brand, rolling out 25+ features, a dozen agents, plus acqui-hires of Sana Labs and Pipedream. It invented “Flex Credits,” a consumption-based pricing plan that let CIOs check an “AI investment” box. That boosted its AI-labeled revenue past $400 million, growing triple digits, but it didn’t change anything users actually do. Admins still click through the same approvals screens, they just type prompts instead of filling fields. Now the calculus is shifting. Large enterprises are auditing legacy systems for AI readiness, and Workday’s 2005-era engine looks like a liability. Tools to rebuild core cloud apps have matured—Tessera and others are already doing AI-native SAP migrations at Fortune 500 scale. Finally, a true challenger can build an HR platform from the ground up for AI workflows, not bolt them onto forms and approvals. Workday’s fortress is showing cracks.