Build a web app that ingests a user’s cash amount, country, account types, debt APRs, time horizon, tax bracket, and liquidity requirements, then ranks practical cash-allocation options. The tool would compare after-tax returns, debt payoff savings, account eligibility, withdrawal restrictions, and risk level, producing a clear action plan with warnings for rule-sensitive cases like TFSA trading, FHSA access, ERI, ISA/LISA limits, and Roth/401k constraints.

Higher interest rates have made cash-management decisions materially more valuable, while more retail investors are using brokerage accounts, tax wrappers, and money market products. Lump sums from settlements, back pay, family help, and home sales are creating urgent short-term allocation questions.