Senior Backend Engineer II - Money

Founded to transform retail finance, Ajaib Group is an Indonesian fintech unicorn breaking barriers to financial access. Having recently secured a $270M Series C—the single largest funding round in Southeast Asia over the past four years—we are backed by premier global investors including Y Combinator, Ribbit Capital, SoftBank, and SBI Holdings. To build world-class products, we assemble world-class talent. Supported by our fully remote work arrangement, our team spans Eastern Europe, the Middle East, India, and Southeast Asia, allowing you to work with brilliant engineers and builders from around the globe from wherever you are. We operate with an impact-driven purpose where everyone is the owner of our customers' satisfaction. Driven by a growth mindset and a fierce will to win, we refuse to settle and constantly push engineering boundaries. Role Overview As a Senior Backend Engineer II in the Money team, you own backend services behind customer accounts and money movement from design to production: ledger and balances, transfers and payments, bank integrations, interest and statements, and daily processing. You design for exactness, auditability and security first, make sound decisions under real traffic, and mentor engineers around you. Design, build and run scalable, secure backend services and APIs for accounts, balances, transfers and payments. Own larger features and services end to end, including monitoring, alerting and on-call follow-up. Design the ledger and balance logic: double-entry records, holds, available and ledger balances, reversals and complete audit trails. Design every money flow for correctness: idempotent requests, clear transaction states, safe retries and handling of unknown results from banks. Integrate with banks and payment networks, and make those integrations resilient to timeouts, delays, cut-off times and duplicate or out-of-order messages. Build and improve reconciliation, settlement and end-of-day batch processing, and drive root-cause fixes for every mismatch. Build risk controls such as transaction limits, velocity checks and fraud rules, with Risk and Compliance. Keep services fast and stable during busy periods, such as salary days and month-end, and plan capacity ahead of known peaks. Lead design reviews and give thoughtful code reviews. Investigate production incidents, run root cause analysis and ship lasting fixes. Mentor mid-level engineers and share knowledge within the team. Work with Product, Finance, Operations, Risk, Compliance and Security to turn requirements into reliable solutions.