Full Stack Software Engineer

About SellAbroad

SellAbroad is building a cross-border commerce infrastructure that enables DTC brands to sell globally with:

• Localized checkout

• Global and local payment options

• Duties and taxes automation

• Order management and shipping integrations

• Faster cross-border delivery

We operate across checkout, payments, OMS, shipping, and multi-currency billing with merchants in multiple regions.

Role Overview

We are seeking a backend-heavy full-stack engineer who can own major components of the platform, including:

• Backend API services

• Subscription and payment logic (Stripe)

• PostgreSQL data modeling

• OMS and order lifecycle logic

• Webhooks and async workflows

• React checkout and dashboard features

• Infra, deployment, and production debugging

This role requires experience with production workloads, third-party integrations, and payment systems.

Responsibilities

Backend Engineering (Primary)

• Build and maintain Node.js backend services

• Design and maintain REST APIs

• Handle async flows including 3DS, renewals, and retries

• Own Stripe integration (payments, subscriptions, invoices, 3DS)

• Maintain PostgreSQL schemas, queries, migrations, and indexes

• Work with order lifecycle state transitions

• Integrate external APIs (Shopify, logistics carriers, etc.)

• Implement logging, metrics, and error handling

• Write modular, maintainable, well-tested code

Integrations and Data Flows

• Implement and consume webhooks (Stripe, Shopify, carriers)

• Work with OAuth/API key authentication flows

• Handle rate limits and retry logic

• Implement idempotency patterns

• Validate JSON and input schemas

Frontend (Secondary)

• Modify or extend React-based checkout UI

• Contribute to merchant/admin dashboards

• Integrate Stripe.js payment components

• Handle state management (Context, Zustand, Redux, etc.)

UI design skills are not required. Functional correctness and stability are primary.

Infra and DevOps

• Deploy and operate services on AWS ECS/EC2/Lambda or similar cloud

• Use Docker and Docker Compose for local environments

• Maintain CI/CD pipelines (GitHub Actions, GitLab CI, etc.)

• Work with metrics, logs, and observability tools

Required Technical Skills

Backend:

• Node.js (primary)

• TypeScript (preferred)

• Express.js, Fastify, NestJS, or Medusa (any one is acceptable)

• REST API development

• Async JavaScript patterns

• Error handling and logging

• Unit and integration testing

Database:

• PostgreSQL (schemas, joins, indexes, migrations)

• Redis (nice to have, for caching or queues)

Payments (Required):

Experience with Stripe in real production workflows involving at least one of the following:

• PaymentIntent API

• Subscriptions

• Invoices

• Off-session charging

• 3DS authentication flows

• Retry and dunning logic

• Webhook orchestration

OMS / Commerce:

Understanding of:

• Order lifecycle state transitions

• Catalog and SKU structures

• Basic tax, duties, or fulfillment concepts (nice to have)

Frontend (Checkout/Dashboards):

• React (production experience)

• State management (Context, Zustand, Redux, or similar)

• Stripe.js integration experience

• TypeScript (nice to have)

Infra / DevOps:

• AWS ECS, EC2, or Lambda (or similar cloud platform)

• Docker and Docker Compose

• CI/CD tools (GitHub Actions, GitLab CI, CircleCI, or similar)

Nice to Have (Not Required)

• Medusa.js, CommerceLayer, Saleor, or similar commerce backends

• Shopify API experience

• Logistics integration experience (Shiprocket, etc.)

• Redis queues or caching

• Event-driven architecture experience

• Observability tools (Sentry, Datadog, Prometheus)

• Multi-currency or multi-region payment systems

• S3, CloudFront, and CDN handling

What Success Looks Like

• Ownership of backend systems end-to-end

• Reliable payment and subscription flows using Stripe

• Robust webhook handling with retries and idempotency

• Clean PostgreSQL models and queries

• Ability to modify React checkout without breaking flows

• Successful third-party integrations without regressions

• Clear documentation and communication

• Consistent debugging and tracing of production issues

Who You Are

• Strong systems thinking habits

• Understand payments and their effect on business metrics

• Communicate clearly in distributed teams

• Able to own features from design to deployment

• Write maintainable code others can iterate on

• Comfortable working in a small team with autonomy

Example Problem Spaces

• Adding regional payment methods and BNPL

• Reducing 3DS friction and improving approval rates

• Implementing duties and taxes inside checkout

• Building returns and refund logic

• Integrating with third-party carriers and OMS providers

• Improving order/event consistency and retries

• Building V3 universal checkout architecture

• Automating merchant onboarding flows

Stack Overview

Backend: Node.js, TypeScript, Express/NestJS/Medusa
Payments: Stripe
Database: PostgreSQL, Redis
Frontend: React, Stripe.js
Infra: AWS, Docker, CI/CD