Senior Backend Engineer - Payments & Wallet

Location : Remote

Employment : Full-time

Experience : 7+ years, preferably including fintech/payments

About the Role :

We are looking for an exceptional Senior Backend Engineer specializing in payments and financial systems to join a small engineering team building and operating a regulated fintech platform.

You will take significant ownership of the systems responsible for moving and accounting for customer money.

This is a senior engineering role with substantial responsibility for transaction integrity, reliability and financial correctness.

What You Will Build and Own :

- Digital wallets

- Financial ledger

- Payment processing

- Salary payment processing

- Payment gateway integrations

- Bank integrations

- Remittance integrations

- Merchant payments

- Withdrawals

- Refunds and reversals

- Transaction limits

- Settlement

- Reconciliation

- Transaction history

- Financial reporting

- Internal operational tools

Responsibilities :

- Design and develop reliable backend services

- Build and maintain financial transaction workflows

- Maintain ledger integrity

- Design transaction state machines

- Implement idempotent APIs and transaction processing

- Handle payment failures, retries and duplicate callbacks

- Implement refund and reversal mechanisms

- Build settlement and reconciliation services

- Integrate banks, payment providers and other financial institutions

- Design scalable database structures

- Build automated reconciliation controls

- Develop monitoring and alerting around financial transactions

- Write comprehensive unit and integration tests

- Participate in architecture and code reviews

- Investigate and resolve production incidents

- Maintain complete auditability of financial transactions

Required Experience :

- Strong backend engineering experience using modern backend technologies.

- Excellent understanding of :

1. SQL/PostgreSQL

2. Relational databases

3. API design

4. Distributed systems

5. Database transactions

6. Concurrency

7. Message queues

8. Event-driven systems

9. Caching

10. Authentication and authorization

11. Secure coding practices

Financial Systems Knowledge :

We strongly prefer candidates who understand :

- Digital wallets

- Double-entry ledgers

- Payment processing

- Transaction lifecycle management

- Settlement

- Reconciliation

- Refunds

- Reversals

- Idempotency

- Financial audit trails

Experience building production systems at a fintech, bank, payment gateway, wallet, acquiring company or payment processor is highly desirable.

The Type of Engineer We Want :

We are not looking for someone who simply implements API specifications.

We want an engineer who asks :

- What happens if the payment provider processes the transaction but our server never receives the response?

- What happens if we receive the same callback twice?

- How do we prove that the customer's balance is correct?

- How do we reconcile our ledger against an external payment provider?

- How do we safely recover from a partial failure?

If these are the types of engineering problems you enjoy solving, we would like to speak with you.