Smart Expense Tracker Enhanced ERD v2.0 models a multi-user personal finance system with seven core tables: Users, Profiles, Categories, Transactions, Budgets, RecurringTransactions, SavingsGoals, and Notifications. Data flows from Users as the central entity through one-to-many relationships to Profiles (1:1), Categories, Transactions, Budgets, RecurringTransactions, SavingsGoals, and Notifications, with optional foreign keys enabling flexible categorization and budget tracking. This schema demonstrates best practices for financial applications: decimal precision for monetary values, temporal tracking with CreatedAt/UpdatedAt, constraint validation (CHECK > 0 for amounts, UNIQUE composite keys for budgets), and support for recurring transactions and savings goals. Fork this diagram on Diagrams.so to customize field names, add audit tables, or extend with transaction tags and multi-currency support. The design balances normalization with query performance, suitable for SaaS expense management platforms or personal finance apps.