# Back-end Engineer - Crypto and Payments > GoTymeX · Ho Chi Minh City, Vietnam (Hybrid) · Full-time · Posted 2026-09-15 **Workplace:** hybrid **Department:** Engineering ## Description About GoTyme The GoTyme Group builds digital banking products for customers in South Africa, the Philippines, and expansion markets across Asia and Africa. GoTymeX is the Group's engineering, product, and design organisation. We build and run the software behind those products. About the product We are building a stablecoin and digital-assets wallet that lets customers hold, send, receive, save, and spend digital dollars through a familiar banking experience. The financial core will be delivered in stages. In the first phase, a managed CASP ledger remains the authoritative operational financial record. GoTyme will build immutable event and audit records, a financial-control projection, and reconciliation capabilities around it. In the next phase, GoTyme's event-sourced, append-only double-entry ledger will become the product and accounting source of truth. The system must stay correct across vendor events, internal state, on-chain settlement, fiat payment rails, card settlement, fees, FX, holds, and operational exceptions. The role We are looking for a hands-on Core Backend Engineer with strong financial-systems and database experience to build Project White's ledger, posting, reconciliation, and financial-control capabilities. You will build systems that calculate balances, record movements of value, prevent duplicate or missing postings, and explain each financial state change. You will work closely with finance, treasury, risk, compliance, operations, vendor-integration engineers, and senior engineers responsible for the wider financial-core design. This is an online transactional-core role. It is not a reporting or data-warehouse position. What you will do - Build and improve an event-sourced, append-only double-entry ledger and its account, journal, posting, balance, hold, fee, FX, and adjustment models. - Implement posting rules and invariants that keep journals balanced, prevent unauthorised value creation or loss, and provide a clear audit trail. - Build transaction-processing flows for authorisation, holds, capture, settlement, reversals, refunds, chargebacks, expiry, corrections, and controlled manual adjustments. - Apply idempotency, deduplication, sequencing, and concurrency controls to payment, card, custody, and blockchain events that may arrive late or more than once. - Build reconciliation controls across the managed CASP ledger, Fireblocks, on-chain data, fiat ramps, card processing, treasury and accounting systems, and GoTyme's financial-control projection. - Build operational workflows for missing events, duplicate notifications, amount or currency mismatches, unbalanced postings, and suspense or repair processes. - Contribute to event schemas, financial data contracts, versioning, replay, and backfill approaches that preserve the audit trail without corrupting balances. - Work with finance and treasury to create accounting evidence, GL exports, reserve and liquidity views, and material for audits and regulators. - Apply strong practices for schema design, migrations, indexing, partitioning, data retention, backups, recovery testing, and database performance. - Take part in financial-core technical design and code reviews. Share what you learn about ledger modelling, database correctness, and safe production practices. - Own monitoring and production support for the components you build. Contribute to reconciliation service levels, incident response, root-cause analysis, and controlled remediation with the wider team. ## Requirements ### Must-have - 5+ years of backend engineering experience, including meaningful hands-on work on payments, ledger, accounting, settlement, core banking, or another high-integrity transactional system. - Experience building, operating, or making substantial contributions to a double-entry ledger, payment posting engine, settlement platform, core-banking subsystem, or equivalent financial system of record. - Strong relational database and SQL skills, ideally PostgreSQL or MySQL. You understand schema modelling, transaction isolation, locking, concurrency, query performance, indexing, migrations, and recovery. - Working understanding of journals, debits and credits, chart of accounts, posting rules, available versus settled balance, holds, reversals, adjustments, fees, FX, and reconciliation. - Practical experience with idempotency, outbox and inbox patterns, event ordering, duplicate delivery, exactly-once-effect design, and failure recovery. - Experience building reconciliations that compare internal and external records, identify breaks, retain evidence, and support controlled repair. - Strong Java or Python experience and a record of building and operating reliable production services. - Experience with event-driven systems, including event replay, schema evolution, auditability, and eventual consistency. - Clear technical communication. You can work with finance, product, compliance, and operational partners to turn requirements into precise models and implementation decisions. ### Strong plus - Experience in stablecoins, digital assets, crypto custody, exchange operations, or on-chain settlement. - Experience reconciling custody or ledger records to blockchain transaction events, confirmations, fees, and failed transactions. - Experience with Fireblocks, TigerBeetle, Modern Treasury, Mambu, Temenos, or similar financial-ledger or custody infrastructure. - Experience in card issuing or processing, payment acquiring, cross-border payments, treasury, FX, or regulated banking. - Experience with AWS serverless and event-driven services such as Lambda, EventBridge, SQS, and Step Functions. Kafka is also useful where it is the selected event platform. - Experience designing data retention, partitioning, archival, and disaster-recovery approaches for financial records. - Experience with accounting exports, general-ledger integration, audit evidence, regulatory evidence, and operational controls. - Experience mentoring other engineers or taking ownership of a defined financial-core component. ## Benefits At **GoTymeX,** opportunities are here for the taking. If you want to be part of our purpose and live and lead through our values, we can offer exciting development opportunities through expanded lateral roles, stretch assignments, or people leadership. **Some of our benefits:** - Competitive salary that recognizes your talent and potential, including 13th salary (pro-rata). - Performance-based bonus and equity participation in Tyme Group. - A fast-moving environment where your ideas and execution actually matter. - Full benefits and salary rank during probation. - Insurance coverage in accordance with Vietnamese labor law, plus premium health care for you and your family. - Generous 20 days of leave annually, including 15 annual leave + 3 sick leave + 1 birthday leave + 1 Christmas leave. - Meal and parking allowances covered by the company. - Hybrid working model with flexibility to work from home or the office. - Values-driven, international working environment and agile culture. - Work-life balance 40-hr per week from Mon to Fri. ## Apply [Apply at GoTymeX](https://apply.workable.com/gotymex/j/3EC5279C3F/apply) --- Powered by [Workable](https://www.workable.com)