Backend Developer

About the role

We're in flight on a platform migration to Shopify Plus B2B, with a legacy on premise ERP as the system-of-record ERP. This role is central to designing and building the middleware/integration layer that connects Shopify to ERP and surrounding systems (payments, tax, inventory, fulfillment, pricing). This is a complex, high-stakes migration involving real-time and batch data sync, custom B2B logic, and payment processing — not a simple app-to-app connector job.

Expected Contract Duration: 4 months

Responsibilities

• Design and build middleware services (Node.js/NestJS) that synchronize orders, customers, pricing, inventory, and fulfillment data between Shopify B2B and ERP
• Architect resilient integration patterns: queues, retries, idempotency, reconciliation, and error recovery for high-volume transactional data
• Build and consume REST/GraphQL APIs (Shopify Admin/Storefront APIs, ERP APIs/EDI, and any third-party services)
• Implement B2B-specific logic: company/location accounts, tiered/contract pricing, custom catalogs, payment terms (net terms), quoting, and approval workflows
• Integrate payment processing (tokenization, authorization/capture flows, refunds, reconciliation) in a way that's PCI-aware and auditable
• Work closely with the ERP functional team to map data models and business rules between systems
• Write tests, documentation, and runbooks; participate in code review and architecture discussions
• Support cutover planning: data migration, dual run/parallel testing, and rollback strategy

Qualifications

• 4+ years professional backend software development experience (Engineer 2 baseline)
• Strong proficiency in production NestJS (modules, providers, DI, guards/interceptors, decorators)
• Solid TypeScript fundamentals; comfortable owning services end-to-end, not just feature tickets
• Experience integrating with at least one ERP or large enterprise system (order management, inventory, financials) via API, EDI, flat file, or message queue
• Experience building or consuming Shopify APIs (Admin API, GraphQL, webhooks, or apps) — Shopify Plus experience a plus
• Working knowledge of relational databases (Postgres/MySQL) and schema design for transactional data
• Experience with asynchronous/event-driven architecture: message queues (SQS, RabbitMQ, Kafka, or similar), background jobs, retry/backoff patterns
• Understanding of idempotency, data consistency, and reconciliation in distributed systems (critical for order/payment sync)
• Comfortable working independently in an ambiguous, evolving integration landscape — this isn't a fully-spec'd ticket queue
• Strong communication skills; able to work directly with ERP/functional stakeholders, not just engineers

Nice to Have

• Direct experience with mid-market/enterprise ERPs — Infor CloudSuite, NetSuite, Epicor, Dynamics 365 including its API layer, IDO/business logic, or EDI patterns
• Experience with Shopify B2B features: company accounts, B2B checkout, customer-specific catalogs/pricing, quoting
• Experience with payment gateways/processors (Shopify Payments, Stripe, Authorize.net, Adyen, or similar) — auth/capture, refunds, chargebacks, tokenization, PCI-DSS awareness
• Prior experience on a platform migration (legacy/custom → SaaS commerce platform), especially with a cutover/parallel-run phase
• Familiarity with middleware/iPaaS patterns or tools (custom middleware, MuleSoft, Boomi, Celigo, or similar) even if this build is fully custom
• Experience with infrastructure/deployment: Docker, CI/CD, AWS/GCP/Azure, observability (logging, tracing, alerting) for production integration pipelines
• Background working with high-volume B2B commerce (large order counts, complex pricing rules, multi-entity/multi-warehouse)
• Familiarity with GraphQL schema design for internal middleware APIs
• Domain experience in [industry — e.g., wholesale distribution, manufacturing, apparel] if applicable to the brand
• Experience with tax engines (Avalara, Vertex) or fulfillment/3PL integrations
• Experience with EDI (X12/EDIFACT) for order, invoice, or ASN transactions if SX.e integration relies on it

#LI-DNI

Vaan is a Shopify Platinum design & technology agency and the home of Brand Conversion Design.

We migrate, design, and build high performing eCommerce experiences leveraging our Brand Conversion Design framework, industry partnerships & deep eCommerce technical expertise. Solving the tension between optimization and design, we help brands make the most of their eCommerce.

Requires 4+ years of backend development, strong NestJS and TypeScript, ERP and Shopify API integration, relational databases, asynchronous architecture, distributed-system consistency, and stakeholder communication.

Key Responsibilities

• building middleware
• architecting integrations
• supporting cutover

Skills & Tools

Node.js, NestJS, TypeScript, REST, GraphQL, Shopify Admin API, Shopify Storefront API, EDI, Postgres, MySQL, SQS, RabbitMQ, Kafka, Infor CloudSuite, NetSuite, Epicor, Dynamics 365, Shopify Payments, Stripe, Authorize.net, Adyen, MuleSoft, Boomi, Celigo, Docker, CI/CD, AWS, GCP, Azure, Avalara, Vertex, X12, EDIFACT

Job Details

• Category: Software Development
• Seniority: Mid Level
• Commitment: Contract
• Workplace: Remote — Canada
• Languages: English

About The Vaan Group

A Shopify Platinum design and technology agency that builds high-performing eCommerce experiences. — Industry: Information Technology