Back End Developer

Job Brief

We are looking for a Backend Engineer with hands-on Node.js, NestJS, and PostgreSQL experience to build and own the backend of our POS platform. You will design and ship scalable backend services across sales transactions, inventory, payments, loyalty, and reporting, with real ownership of the modules you work on.

Node.js with NestJS and PostgreSQL is the stack we are building on, and it is what we are hiring for. A large part of your work will be designing new services in NestJS and modelling high-volume transactional data in PostgreSQL: schema design, indexing, transactions, and query performance at POS scale.

Parts of the platform still run on Laravel, PHP, and MySQL. You will help move these to modern services in safe, incremental steps, without disrupting live merchant operations. Prior Laravel or PHP exposure is useful for reading the existing codebase.

This is a high-ownership, hands-on role in a fast-growing startup. You will work directly with product, frontend, QA, and DevOps, and you will help shape how the engineering team works, not just what it ships.

Key Responsibilities

Technical Ownership

• Own backend architecture for the POS platform: API design, service boundaries, data models, and integration patterns.
• Establish and champion engineering standards: code review practices, testing strategy, documentation, and release discipline.
• Contribute to technical planning and estimation with product and engineering leadership.
• Collaborate with other backend engineers through code reviews.

Platform and Delivery

• Design and develop scalable backend systems for POS operations across retail, restaurants, and multi-location merchants.
• Build and maintain secure, high-performance RESTful APIs for web, mobile, and in-store clients.
• Own modules for sales transactions, inventory, customer management, loyalty, and reporting data feeds.
• Integrate payment gateways, POS hardware services, and third-party business systems.
• Work hands-on with PostgreSQL for high-volume transactional workloads and reporting use cases.
• Implement authentication, authorization, and multi-tenant data isolation best practices.
• Support multi-store and multi-location POS operations with reliability and performance at scale.

Migration and Modernization

• Work hands-on in NestJS to build new services as the platform moves off the legacy Laravel and PHP stack.
• Define API contracts and integration boundaries between legacy and new services.
• Identify high-risk areas (payments, inventory sync, reporting) and prioritize safe migration paths.

Operations

• Troubleshoot production issues and drive root-cause fixes, not just patches.
• Work collaboratively with cross-functional teams, including QA and DevOps.
• Own error tracking and incident follow-up, including writing postmortems for merchant-impacting issues

Who You Are

• You thrive in a high-growth startup: ambiguous requirements, shifting priorities, and the need to ship while building for scale.
• You are hands-on. You write code, review PRs, and debug production issues.
• You are practical about legacy code. You can judge when to clean up existing code, when to replace it gradually with a new service, and when to leave working code alone.

Required Technical Skills

• Hands-on experience with Node.js and the NestJS framework.
• Automated testing with Jest (or similar): unit, integration, and API-level tests.
• Strong understanding of RESTful API development.
• Redis and job queues (similar) for async work.
• Expertise in PostgreSQL: schema design, indexing, query optimization, transactions, and data integrity at scale.
• Experience working with POS, Retail, Restaurant, ERP, Inventory, or E-commerce applications.
• Payment gateway integrations.
• Authentication and authorization: JWT, OAuth, role-based access, and multi-tenant scoping.
• Strong understanding of database indexing, transactions, and data integrity.
• Git, code review workflows, and collaborative development.

Preferred Skills

• Experience with migration from a monolith to services (Laravel to NestJS/Node, or similar).
• Working knowledge of Laravel and PHP, enough to read and maintain the existing codebase.
• Multi-tenant SaaS architecture and tenant isolation patterns.
• POS hardware integrations: barcode scanners, receipt printers, cash drawers.
• Microservices architecture, message queues, and event-driven patterns.
• Experience designing sync APIs for offline-capable clients, including handling delayed, out-of-order, and duplicate writes from terminals that were disconnected.
• Familiarity with idempotency keys, conflict resolution strategies, and reconciliation logic for transactions created while offline.

Nice-to-Have

• Restaurant POS experience
• Retail management systems
• Loyalty and rewards systems
• Subscription billing systems
• Docker and containerized deployments
• Microservices architecture