Enterprise mobile app development requires resolving MDM enrollment strategy, RBAC models, and legacy API integration before the first sprint — not during UAT. Key architectural decisions include choosing between SAML 2.0 and OAuth 2.0 for Active Directory federation, selecting MDM/MAM controls for BYOD policies, and designing offline-first sync with conflict resolution for ERP-connected apps. The guide covers build vs. buy vs. modernize TCO comparisons (5-year horizon), framework tradeoffs between React Native, Flutter, and Kotlin Multiplatform for MDM SDK compatibility, a seven-phase development process with compliance gates, team structure requirements, and cost ranges from $100K to $1.2M+ depending on integration depth. Legacy system integration (SAP, Oracle, AS/400) typically consumes 40-55% of project budget and is the most underestimated cost driver.
