Backend Engineer - Crypto and Payments
No salary listed
Senior
Ho Chi Minh City, Vietnam
Remote
Software EngineeringBackend Engineering
About the job
Requirements
- At least 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 substantially contributing 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, including 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, foreign exchange, 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 and ability to work with finance, product, compliance, and operational partners to turn requirements into precise models and implementation decisions.
- Comfort choosing and applying suitable patterns for a financial system of record, including event-sourced, append-only double-entry ledgers, posting engines, financial-control projections, reconciliation control towers, and accounting evidence.
- Strong relational database skills; transactional correctness and performance are more important than a particular database brand.
- Familiarity with engineering practices including explicit financial invariants, peer review of financial changes, automated unit, integration, and contract tests, controlled migrations, reconciliation monitoring, staged rollout, and incident readiness.
Responsibilities
- Build and improve an event-sourced, append-only double-entry ledger and its account, journal, posting, balance, hold, fee, foreign-exchange, and adjustment models.
- Implement posting rules and invariants that keep journals balanced, prevent unauthorized value creation or loss, and provide a clear audit trail.
- Build transaction-processing flows for authorization, 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 the 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, general-ledger 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, and share knowledge about ledger modelling, database correctness, and safe production practices.
- Own monitoring and production support for built components; contribute to reconciliation service levels, incident response, root-cause analysis, and controlled remediation with the wider team.
Desired Qualifications
- 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, foreign exchange, or regulated banking.
- Experience with AWS serverless and event-driven services such as Lambda, EventBridge, SQS, and Step Functions; Kafka experience 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.
About the company
GoTymeX builds digital banking products for consumers and small businesses through GoTyme's banks and financing operations in emerging markets. Its design, engineering and data teams create the customer applications and underlying systems used for accounts, payments, credit cards and loans. The hub supports banks in South Africa and the Philippines and financing businesses in Indonesia and Hong Kong, adapting technology to different local banking requirements. Its products combine mobile services with physical customer access through the banking group's retail partnerships. Established in 2016, GoTymeX is headquartered in Ho Chi Minh City, Vietnam.
Company Size
501-1,000
Company Stage
N/A
Total Funding
N/A
Headquarters
Singapore
Founded
2016
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Simplify's Take
What believers are saying
- Vietnam GoTymeX staff receive family healthcare: the hub also lists 15 days of annual leave.
- GoTymeX reported faster diagnosis in September 2026: incident-sample tests cut the median from 34.5 to 10 minutes.
- Vietnam GoTymeX staff have hybrid flexibility: the hub describes productivity and value creation as its focus.
What critics are saying
- GoTymeX engineers support continuous banking: its platform targets service stability around the clock, every day.
- GoTymeX delivery crosses bank priorities: its operating-model partner describes competing requests, handovers and fragmented market teams.
- GoTyme's engineering pace is brisk: the group's careers site advertises 120 code releases every week.
What makes GoTymeX unique
- GoTymeX product teams include bank commercial representatives: cross-functional pods own entire product families, such as savings accounts.
- GoTymeX keeps engineers in control of AI operations: every proposed production action requires human review and approval.
- GoTymeX deploys software continuously: its platform combines containerised services, automated testing and cloud hosting.
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Benefits
- Health Insurance
- Meal Benefits
- Paid Vacation
- Paid Sick Leave
- Performance Bonus
- Company Equity