Senior Full‑Stack Developer (Payments Orchestration, React/Next.js, MedusaJS)

## About the role We're looking for a Senior Full‑Stack Engineer to own our payments layer and storefront experience. You'll lead the integration of Hyperswitch (open‑source payment orchestrator) into our MedusaJS commerce stack, and build high‑performance React/Next.js frontends on top of it. If you've actually shipped complex payment flows (multiple PSPs, routing, retries, 3DS, wallets, etc.) and enjoy working across backend and frontend, this role is for you. ## What you'll do - Own payment orchestration end‑to‑end - Integrate Hyperswitch with MedusaJS using the existing plugin and/or custom extensions. - Design and maintain payment flows for cards, wallets (Apple Pay, Google Pay, PayPal), BNPL and local payment methods using Hyperswitch's unified API and routing capabilities. - Build great checkout and account experiences - Implement React/Next.js checkout and billing UIs using Hyperswitch's React/JS SDKs (hyper‑js, HyperElements, Unified Checkout) and Medusa APIs. - Handle payment state, error handling, 3DS and SCA flows, and post‑payment UX (receipts, retries, dunning flows). - Design robust backend payments architecture - Extend MedusaJS backends and services to support Hyperswitch payment intents, webhooks, refunds, payouts and reconciliation. - Implement secure server‑side endpoints to create and confirm payments, manage client secrets, and sync payment status to orders and subscriptions. - Optimize for reliability, cost and observability - Use Hyperswitch's routing and analytics to monitor authorization rates, failures and fees, and continuously improve success rates and costs. - Instrument metrics, logging and alerting for payment flows (timeouts, PSP failures, webhook issues), and design safe fallbacks and retries. - Collaborate across product, growth and ops - Work with product and growth teams to support experiments on pricing, payment methods, and check‑out UX. - Provide engineering input on PSP selection, routing rules and risk/fraud integrations. ## Must‑have experience - Full‑stack engineering (5+ years) - Strong in TypeScript/JavaScript and Node.js with modern frameworks (e.g. MedusaJS, Express, NestJS). - Solid Python or Node backend experience building secure REST APIs and background jobs. - Payment orchestration & processors - Proven track record integrating multiple PSPs (e.g. Stripe, Adyen, Braintree, Checkout.com, PayPal) behind a single abstraction or orchestration layer. - Experience with payment intents, webhooks, 3DS/SCA, refunds, chargebacks, subscription billing, and idempotency. - Hyperswitch or similar platforms - Hands‑on experience with Hyperswitch (preferred) or a similar open‑source payment orchestrator (routing rules, connectors, unified checkout). - Bonus if you've already used or contributed to the Hyperswitch MedusaJS plugin or built custom Medusa payment modules. - React / Next.js checkout and account flows - Deep experience building React/Next.js frontends, ideally using payment SDKs (e.g. Stripe Elements, HyperElements or equivalent). - Comfortable with state management, client‑side validation, and secure handling of payment details (never exposing secrets on the client). - Cloud, security and reliability - Experience deploying Node/Medusa/Next.js in a cloud environment (AWS, GCP or similar). - Familiarity with PCI‑aware architectures, secure key management, and secrets handling. - Strong understanding of observability (logs, metrics, tracing) for critical payment flows. ## Nice to have - Experience with Rust‑based services or contributing to open‑source payment projects like Hyperswitch. - Exposure to fraud/risk tools, 3DS providers, or subscription/dunning platforms. - Prior work on e‑commerce or B2B SaaS billing systems. If this sounds like you, share your GitHub, key payment projects (especially any Hyperswitch + MedusaJS work), and a short note on a difficult payments problem you've solved.