Sanad is a real-estate investment platform in Saudi Arabia. Investors verify their identity through Absher, top up a wallet, buy units in income-generating properties and receive their returns in the same wallet. As a part-time full-stack engineer, I built its API and its admin dashboard.
The platform was new, and real money had to move through it safely.
Money that always adds up. Every balance had to be explainable, movement by movement.No half-finished investments. Units, money and fees had to change together, or not at all.Returns for every investor. Paying each investor by hand would be slow and error-prone.Control for the team. Deposits, withdrawals and bank accounts needed a person to approve them.What could go wrong, and what prevents it The risk What the platform does a balance nobody can trace back to its movements a ledger: every movement linked to the one before, with the balance after it units sold but not paid for, or paid for but not sold one all-or-nothing step for units, money and fees, confirmed by a code returns worked out by hand, investor by investor a schedule of returns, paid per unit to every investor in one action money moving in or out with nobody checking it deposits, withdrawals and bank accounts approved by a person on the team Each risk has one safeguard in the platform, and I built each of them. Built the API from its first commit, on Domain-Driven Design, split into more than ten domains. Built the parts where money moves: the wallet ledger, the investment flow and the returns. Built sign-in with one-time codes, the approvals, and the connections to Absher and payment gateways. Built the admin dashboard on my own. Helped build the investor app's home and account pages, and guided the engineer who built the rest. Wrote tests for the money paths. Shares in income properties Investors buy units in income-generating properties, from the website or the app. Verified investors Every investor verifies their identity through Absher before investing. A wallet for every investor Top up from a bank account, invest from the balance and withdraw back. Returns on a schedule Returns are paid once, monthly or yearly, straight into the wallet. Confirmed by a code Signing in and every investment are confirmed by SMS. Arabic and English The apps, the messages and every wallet movement read in either language. Sanad at a glance Investors Investor app Website Operations team Admin dashboard the API · one back end Investor API Website API Admin API investors and admins sign in separately more than ten domains, each behind a contract Security Users Banks Opportunities Roles Settings Content Locations Finance · wallet ledger Investments & returns Absher identity verification Payment gateways online payments SMS codes and confirmations; in testing, a team chat the money paths are covered by tests Database Queue for messages Three front ends share one API, and the money lives in two domains at its centre. The wallet ledger one investor’s wallet, oldest movement first movement where it moves balance after Deposit + bank account to wallet Investment − wallet to investment Fees − wallet to investment Return + returns to wallet Withdrawal − wallet to bank account each movement points to the one before it, and carries the balance after it the database writes the link and the balance itself, on every movement the wallet’s balance is always its last movement every movement also reads as one line, in Arabic or English Each movement points to the one before it, so a balance is always the end of a chain. The application never writes a balance: it only adds movements, and the database keeps every wallet in step with them.
Investing in one step Investor picks the units enters the code sent by SMS one transaction · all or nothing checks the code is right the investor is verified the opportunity is open enough units are left within the investor’s limits the wallet covers it all changes reserve the units record the investment debit the wallet + fees confirmation by SMS units and money always change together if any check fails, nothing changes, and the investor is told why Every check runs before anything changes, and every change happens together. Returns for every investor an opportunity’s life Soon Available Offering complete Profit distribution Liquidation complete Completed investors buy units returns are paid 1 · A return plan a fixed amount or a percentage paid once, monthly or yearly between a start and end date it can change until the first period is paid 2 · A schedule 1 2 3 4 … each period’s return, split per unit sold 3 · Paying a period an admin confirms their password and records a profit or a loss each investor gets units × share one transaction, one ledger row each The plan is set once; paying a period is one confirmed action that pays every investor.