Lead Backend Engineer: POS Integrations & APIs

On; Greater London; Hybrid; GBP 75,000 - 110,000; Full time

Job summary

On is seeking a Backend Engineer to drive the integration of our POS platform with ERP, OMS, CRM, and loyalty engines. You’ll design resilient services, shape event-driven data flows, and ensure store operations stay fast and reliable.

You’ll join the Retail Experience team to connect physical and digital storefronts, crafting clean APIs and scalable, secure integrations for a future-ready commerce platform.

Qualifications

• 3+ years of backend engineering with Node.js/TypeScript.
• Proven track record integrating APIs across commerce, ERP, OMS or CRM.
• Familiar with headless commerce, microservices and composable architecture.
• Experience with message brokers (Kafka) and cloud-native design.

Responsibilities

• Design, build, and scale backend services powering POS integrations across ERP, eCom, CRM, inventory and loyalty.
• Develop REST and GraphQL APIs that are performant, secure, and easy to consume.
• Implement real-time and batch data sync, OAuth2/SSO auth, and secure event pipelines.
• Contribute to cloud-native, event-driven architecture for global retail operations.

Skills

Node.js

TypeScript

API integration

Headless commerce

Microservices

Composable architecture

Kafka

PostgreSQL

Terraform

Cloud platforms

OAuth2

Tools

Kafka

Terraform

AWS

GCP

Azure

Job description

On is seeking a Backend Engineer to drive the integration of our POS platform with ERP, OMS, CRM, and loyalty engines. You’ll design resilient services, shape event-driven data flows, and ensure store operations stay fast and reliable.

You’ll join the Retail Experience team to connect physical and digital storefronts, crafting clean APIs and scalable, secure integrations for a future-ready commerce platform.