Senior Backend Engineer

ScopeX moves real money across borders. We are hiring a senior engineer with a core banking or payments background to own the integrity, reliability, and security of our ledger, wallet, and back-office platforms. You will set the engineering standard for how money moves through our systems: correct under concurrency, reconcilable to the cent, and safe by design. This is a hands-on role, so you will write the code, the tests, and the infrastructure definitions yourself. **What you will do** * Ledger and transaction integrity: design and maintain fund-moving flows (payments, payouts, refunds, transfers, rewards) that are atomic, idempotent, and fully reconcilable across internal services and external payment partners. * Partner integrations: build and harden integrations with banking, payment, custody, and KYC providers, including secure callback handling, state-machine-driven transaction lifecycles, and automated reconciliation. * Authentication and authorization: own customer and staff authentication, session management, and a consistent, least-privilege permission model across services. * Operational controls: implement banking-grade controls for back-office operations, including strong step-up authentication, maker-checker approval on sensitive actions, and tamper-evident audit trails. * Engineering assurance: raise the bar on testing and release quality with concurrency and negative-path tests, CI release gates, and dependency and runtime hygiene. **What we need** * Must have at least 5+ years building core banking, ledger, payment, or wallet systems in a bank, fintech, payment processor, or iGaming platform, covering double-entry accounting, idempotent transfers, reconciliation. * Production depth in at least two of Go, Nodejs/TypeScript, Python/Django. * Strong MySQL/RDS: transactions, locking, constraints, replication semantics, and CDC. * Practical security engineering: least privilege, WebAuthn/step-up authentication, audit-log design * A habit of writing concurrency and failure-path tests, and of writing clear design documents and runbooks.