Backend Developer : Payment API Gateway

Pay-Jet is building a proprietary API orchestration layer: a single integration point for POS manufacturers and eCommerce partners. Behind it, Pay-Jet routes to acquirers, PayPal, BNPL, and other payment rails, so partners never get direct access to the underlying provider APIs or keys. You will take technical ownership of this API gateway, from specification through production. eCommerce and POS connectivity are being developed in parallel, not sequentially. You will work closely with our existing development team and bring your own judgment to technology choices and architecture. The foundational decisions, such as service topology, data ownership, and the language or stack, are made jointly with the founder and an external PCI advisor in your first weeks. They are not yours to decide alone., * Help define and then implement the API gateway architecture for the eCom and POS channels, which are developed simultaneously

• Jointly decide the foundational architecture together with the founder and an external PCI advisor. This is the first deliverable of the role, not a pre-set spec to implement
• Integrate different payment providers
• Ensure sensitive cardholder data stays decoupled from the API specification, maintaining SAQ A scope
• (Optional) Work closely with an external PCI advisor, since security-relevant architecture decisions get reviewed externally before implementation
• Design webhook processing, idempotency, and error handling for multi-provider routing
• Document the API specification for external partners

• Several years of backend development experience, more than 5, with demonstrable experience in payments
• Strong API design skills
• Most likely the project will be in TypeScript/Nide.js: Experience is preferred, but a willingness to work in this stack matters more than having used it before
• Working understanding of PCI DSS requirements, or a strong willingness to build this up quickly
• Ability to make and justify technical decisions, while accepting that the security-critical ones go through a joint review rather than being made solo
• Comfortable working where some foundational decisions are still open and get resolved together with you early on

• Real ownership of a strategically central product. The gateway is the technological foundation for Pay-Jet’s next growth phase
• Direct collaboration with the founder and short decision paths
• An established company, founded 2018, with roughly 30 employees, that still moves at start-up pace on key tech decisions
• A modern environment and a fun team

Gehalt: 70.000,00€ - 95.000,00€ pro Jahr

Bewerbungsfrage(n):

• Have you worked in the payment industry (designing/developing a PSP/NSP or acquiring host)?

Arbeitsort: Homeoffice