Personal finance and debt management platform — formulas, goals, automation, and Telegram alerts

The problem

Spreadsheets can't push alerts, calculate compounding debt dynamically, or simulate payoff strategies. The goal was a purpose-built platform that models real payment formulas, tracks every debt arrangement type, and proactively surfaces due dates, overspend, and cash flow problems before they compound.

Approach

• Flask API with MySQL backend and a background scheduler for daily interest accrual, minimum payment recalculation, recurring rule processing, and Telegram notification dispatch
• Credit card minimum payment formula with configurable basis days, daily interest accrual, credit utilisation tracking, billing cycle configuration, and statement cycle reminders
• Loan amortisation support (fixed monthly, payroll deduction, one-time due, hard due date, and flexible arrangements) with balance auto-update and paid-off detection
• Debt strategy simulation — snowball (smallest balance first) and avalanche (highest interest first) with extra payment scenarios, total interest cost projections, and month-by-month payoff schedules
• Savings goals with deposit and withdrawal tracking, target amounts and dates, goal progress percentages, and undo support via a full audit trail
• Budget management with category-based allocation, real-time spending vs. budget comparison, and overspend detection
• Cash flow planning — projected monthly income, expenses, and payments; negative runway alerts; and emergency fund runway calculation
• Financial health score (0–100) from savings rate, emergency runway, debt-to-savings ratio, and credit utilisation, with colour-coded status and AI-generated action items
• Recurring transaction rules engine — income, expense, payment, charge, saving, and budget entries across daily, weekly, bi-weekly, and monthly cadences with auto-post or manual confirmation
• Telegram bot with granular per-alert toggles: overspend, upcoming due dates, credit utilisation (80%+), debt paid-off milestones, negative cash flow, monthly summaries, and statement cycle reminders
• React + Vite + TypeScript PWA mobile companion served from a dedicated endpoint — quick-entry expense forms, due-date dashboard, and recent activity feed, installable on any device

Outcome

• Every debt, budget, goal, and cash flow projection in one place — no spreadsheet drift, no missed due dates
• Telegram alerts surface overspend, due dates, credit risk, and monthly summaries without opening the app
• Payoff strategy simulation turns abstract debt into a concrete month-by-month plan with real interest cost comparisons