A cloud-native brokerage trading platform by Oriana Tech, integrated with a national stock exchange over FIX.
Kotlin · Microservices · BFF · FIX 4.4
Role
Lead architect. I set the backend and frontend architecture and the platform's API contracts, directed the team's execution, and built parts of both sides myself.
Problem
Brokerages in emerging capital markets are stuck between legacy on-premise core systems and foreign platforms that do not understand local regulation. Zion, the product of my company Oriana Tech, is a cloud-native brokerage core built to run a full trading operation, from investor onboarding to order execution and settlement, while meeting strict financial and audit requirements.
Approach
Designed as an API-first microservices platform in a Kotlin monorepo, with a backend-for-frontend layer that shapes data for an admin console and an investor mobile app. Core services own clear domains: a double-entry ledger as the source of truth for balances and settlement, an order-management service for the order lifecycle and risk checks, and a dedicated FIX 4.4 connector to the exchange matching engine. Each service follows a hexagonal architecture with a framework-free domain. Financial integrity is enforced with BigDecimal money, pessimistic locking to prevent double-spending, idempotent orders, and an append-only audit trail the application cannot disable. Identity runs on Kotauth, my own OAuth2/OIDC platform. The whole system deploys on AWS ECS.