Jeyanth V.

What the deployed app does

• Money: spending and income by category, category budgets, safe-to-spend per day, a spend-pace chart and bank-statement CSV import with auto-categorisation and duplicate skipping.
• Bank accounts: balances side by side, a statement with running balance per account, transfers that never count as spending, and a 'match bank balance' correction.
• Plans & debt: every SIP, RD, gold chit and EMI with instalments done and left, a 'what frees up when' timeline, a debt-free date and a prepayment simulator.
• Portfolio: stocks, ETFs, mutual funds, deposits, bonds and gold; holdings, average cost, P/L and XIRR derived from transactions with FIFO lots.
• India tax lots: per-lot holding period, unrealised STCG/LTCG, remaining LTCG exemption and a FIFO-aware zero-tax harvest helper. Rates and thresholds are editable.
• Goals and savings wins: short and long-term goals with the monthly amount needed, plus milestones and streaks that respect reduced motion.
• Command palette (Ctrl/⌘ K), encrypted JSON backup and restore, CSV export, light and dark themes, a privacy mode that blurs amounts, installable as a PWA.

Architecture

Local-first. The browser's IndexedDB (through Dexie) is the source of truth, so the app works fully offline. Signing in adds a per-user cloud copy.

• UI: React, TypeScript and Vite with Tailwind CSS, Recharts and a hand-built component set.
• Domain layer: pure, unit-tested TypeScript for FIFO lots, XIRR, tax set-off, allocation, cash flow, payday and debt schedules.
• Sync: table hooks write changes to an outbox; the engine pushes, then pulls by a server-assigned cursor. Last write wins and deletes are tombstones. Sample data never syncs.
• Supabase: email magic-link and Google sign-in, one generic records table with row-level security forced so each user sees only their rows, a per-user write quota and self-serve account deletion.
• Cloudflare Worker price API: CORS allow-list, per-IP and per-user rate limits, Supabase JWT verification, AMFI NAVs and Google Finance quotes with a Yahoo Finance fallback.
• Static frontend on Vercel with a strict Content-Security-Policy, HSTS and frame protections.

Data handling

• Money is stored as integer paise; dates are plain calendar dates. No floating-point rupees.
• Holdings and balances are never stored as truth: they are derived from dated transactions, so every figure can be traced back.
• A price is never shown without its date and source. Manual prices always work.
• Backups can be encrypted in the browser (AES-256-GCM with a PBKDF2-derived key) and are validated before a restore replaces anything.

Engineering trade-offs

• Last-write-wins sync instead of field-level merging: simpler to reason about for a single person on a few devices, at the cost of occasionally losing a concurrent edit.
• Google Finance has no public API, so quotes come from its quote page with Yahoo as a fallback. Either can change, so the UI always says when a holding can't be priced.
• Tax modelling is explicit about scope: surcharge, carried-forward losses and 2018 grandfathering are listed as not modelled rather than approximated.
• Kaasu is a personal tracker, not investment or tax advice, and the app says so.