Payment Gateway Engineer

Primary responsibilities

• Build and maintain the payment gateway — authorisation, capture, refund, void and the state machine underneath them
• Integrate acquirers and payment service providers, each of which behaves differently from its documentation
• Make every path idempotent, because a network blip that causes a retry must never become a double charge
• Implement 3-D Secure and the strong customer authentication requirements that apply in each market
• Build the tokenisation and vaulting that keeps card data out of scope
• Handle webhooks and asynchronous notifications with the ordering and replay problems they bring
• Design for the provider being down: routing, failover and a queue that survives it

Skills required

Day to day this role works with Node.js, Payments, API Integration and PCI DSS.

• Five or more years building payment systems in production
• Have integrated more than one acquirer or PSP and know how differently they behave
• Understand idempotency and reconciliation as design problems, not afterthoughts
• Three or more years building payment systems in production
• Authorisation, capture, refund and void flows and the state machine underneath them
• Acquirer and PSP integration, against providers that behave differently from their documentation
• Idempotency on every path — a retry must never become a double charge
• 3-D Secure and the strong customer authentication requirements of each market
• Tokenisation and vaulting to keep card data out of scope
• Webhook and asynchronous notification handling, with ordering and replay

Preferred

None of these are required. They are the things that would help, and a strong application is regularly missing all of them.

• PCI DSS scope experience
• Multiple acquirer integrations
• Ledger or double-entry systems

Working in Payments & Gateway Engineering

Double-entry thinking, strong reconciliation, and integrations with more than one provider because they all behave differently. PCI DSS scope is a real constraint on architecture, not a checkbox.

Payments engineering is a specialism that transfers anywhere, and the surface here spans gateway, settlement and cross-border.

About Bengaluru

Bengaluru is our largest site and where most of engineering, product, design, data and AI sit. The office is in the eastern corridor, and the majority of these roles are remote-friendly with the team meeting in person a few days a week.

The city has the deepest technology labour market in India, which cuts both ways: the work is here, and so is everyone else commuting to it. Teams are deliberate about core hours because a cross-city commute in the evening peak can take longer than the meeting it was for.