Back-end Engineer (Trading Infrastructure)

Senior backend engineer with 5+ years of experience building production systemsC1 English level or higherProven production experience integrating trading platform APIs (Rithmic/R|API+, Tradovate, Ignite, cTrader, MetaTrader, CQG, or similar)Strong C# for backend service developmentExpert-level REST API consumption: pagination, retry logic with exponential backoff, rate limiting, token managementProduction webhook implementation with signature verification (Ed25519 or HMAC) and idempotent event processingRobust error handling, monitoring, and failover system design for high-stakes financial environmentsAdvanced SQL skills (PostgreSQL preferred) including cross-table data integrity debuggingSkillsC#.NETREST APIPostgreSQLWebhook securityEd25519HMACTrading platform APIsRithmicR|API+cTrader Own all trading platform integrations: account creation, suspension, reactivation, and balance adjustments across current (Ignite/Tickblaze) and future platformsEnsure reliable end-of-day reporting workflows that process correctly and update trader dashboards without disruptionBuild monitoring and alerting around EOD failures, sync issues, and webhook delivery failures to catch problems before trader impactDevelop automatic recovery systems with retry logic, token refresh, and idempotent operations to minimize downtime and manual interventionReconcile WooCommerce subscription statuses with trading accounts to ensure only paid users retain active accessCreate audit tools to detect and resolve ghost accounts, orphan statistics, and balance chain inconsistencies You will own the entire trading account integration and reporting infrastructure for a high-volume prop firm. This role centers on managing account lifecycles across multiple trading platforms (Tradovate, Rithmic, cTrader, MetaTrader, CQG), building failsafe end-of-day processing workflows, and ensuring subscription-to-account integrity. Your systems will handle significant financial flows, requiring resilient error handling, automatic recovery mechanisms, and proactive monitoring to prevent trader impact. You will work independently while coordinating with WooCommerce and frontend teams to maintain seamless subscription flows. JavaSpring BootDockerAWSDigitalOceanfintech compliance