Authorial product / full-stack engineering
A portfolio that explains its numbers
A portfolio should explain how it arrived at its balance, profit/loss and contribution limit — including when data is missing.
From real use to verifiable rules
Real use exposes problems beyond an asset register: partial trades, fees, linked stablecoin settlement, historical BRL prices and distinct strategies for the same asset. ImCryptoCat turns these cases into verifiable rules and interfaces for tracking a portfolio.
Engineering decisions
Independent strategies
The same asset can belong to the main portfolio and a speculative strategy. Quantity, average cost, results and history stay separate by strategy, while total wealth remains consolidated.
Technical evidencePosition and strategy exposure models, with regressions for partial trades and closed positions.
Calculations with explicit limits
Acquisition cost is not the current quote. Historical BRL prices use the reference exchange rate for that date. When cost or historical coverage is missing, the interface states the gap rather than inventing performance.
Technical evidenceBalance and historical reconstruction models, with tests for incomplete data and BRL price conversion.
No partial import updates
The CSV is an absolute balance snapshot, not invented purchases. Preview and confirmation precede transactional application; idempotency protects against repeated application and a failure rolls back the entire transaction.
Technical evidencePostgreSQL integration fixtures check history preservation, linked settlement, user isolation and rollback on failure.
From preview to application
An explanation of the balance import flow, not a demonstration with private portfolio data.
01
Preview
Review the balance snapshot and its effects before changing the portfolio.
02
Confirmation
Confirm the reviewed operation while preserving the represented history.
03
Atomic application
Apply with SERIALIZABLE isolation. On failure, no partial updates are retained.
Rollback is a guarantee on failure, not a promise of an undo button for a completed import.
What works today
Positions, purchases and sales, fees and linked stablecoin settlement; ACB average cost, realized and unrealized results; explainable allocation profiles and limits. Charts state their historical coverage and include BTC context from CEI.
TypeScript · NestJS · React Router · Tailwind CSS · PostgreSQL · Redis · Docker
Status and boundaries
In personal use and preparation for a private beta. Local production, load and recovery exercises do not prove public availability or remote capacity. The product does not execute orders or recommend investments.