Recent Work

Problem

DreamBank is one of several products in the Dream ecosystem, alongside DreamBox, DreamFarm and DreamMarket - and the one all of them settle through. The ecosystem itself grew from a different idea: online shopping easily turns into a habit that costs real money, yet research suggests most of the pleasure comes from the search, the choice and the checkout rather than from owning the thing. Dream keeps that experience and removes the cost with virtual currency that never turns into real money. For that to feel real, the money has to behave like money - cards, balances, a history - across every product at once.

Architecture

• Double-entry ledger for play money. Every balance change is a journal entry whose postings sum to zero, posted rows are immutable, and balances are projections rebuildable from postings. A stored balance column would have been far simpler and permanently unexplainable.
• One bucket per card, no wallet. Three cards in one currency are three independent balances, and moving value between them is a real transfer. A pooled user-level balance is explicitly forbidden, so no flow can quietly invent one.
• Cross-currency movement stays explicit. Each ledger account and each posting carries exactly one currency, so no transfer can silently convert. Cross-currency movement is a separate operation that records quote, rate, rate version and expiry before confirmation.
• Rewards are not money yet. Cashback accrues as points in a separate append-only journal and reaches the money ledger only through a confirmed redemption. Points settle only once the reversal window has closed, so a refund cannot drive a point balance negative.
• Counting attempts, not successes. Velocity counters increment while an operation is being evaluated, before the decision, so rejected attempts still count. I traded accuracy as an activity record for immunity to threshold gaming by rapid retries.