Backend Engineer - Crypto and Payments

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.

Why join

• Help build the financial foundations of a global stablecoin product as it moves from managed external infrastructure to a GoTyme-controlled financial core.
• Solve database and distributed-systems problems where correctness protects real customer value.
• Work with senior partners across engineering, finance, treasury, risk, compliance, and operations.
• Shape the architecture and standards that keep the platform safe as it grows.

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.

Technology and ways of working

You do not need experience with every item below. You should be comfortable choosing and applying the right patterns for a financial system of record.

• Financial core: An event-sourced, append-only double-entry ledger, a posting engine, financial-control projections, a reconciliation control tower, and accounting evidence.
• Databases: Strong relational database skills are mandatory. PostgreSQL and MySQL are both relevant. Transactional correctness and performance matter more than a particular database brand.
• Events and processing: AWS serverless patterns, including Lambda, EventBridge, SQS, and workflows. Kafka may be used where it is the selected event platform. We use transactional outbox and inbox patterns and durable idempotency controls.
• External records to reconcile: Managed CASP operational ledger, Fireblocks wallet and transaction events, blockchain data, fiat ramps, card processing, treasury, and the general ledger.
• Engineering practice: Explicit financial invariants, peer review of financial changes, automated unit, integration, and contract tests, controlled migrations, reconciliation monitoring, staged rollout, and incident readiness.