Senior TypeScript Backend Engineer - CoreApps Platform (AI-first, Encore)

Join the CoreApps Platform team, the foundational engineering group at Groupon responsible for the global commerce engine. This senior-level IC role focuses on KTLO stability and platform modernization using an AI-first approach. You will own mission-critical services handling 100,000+ RPM, migrating legacy Java/Ruby systems to TypeScript/Node.js microservices, and leveraging AI coding tools for speed and quality.

Must Have

• Architect and Develop high-throughput, low-latency Core Platform services.
• Drive modernization by refactoring and migrating critical services to TypeScript/Node.js microservices.
• Champion AI-Assisted Development using AI coding tools.
• Ensure Operational Excellence for global, production systems, including incident response and resilience design.
• Design Distributed Systems that are fault-tolerant, self-healing, and resilient.
• Own Complex Commerce Logic for financial systems, order management, and payment processing.
• 6+ years of professional backend software development experience.
• Strong professional experience in building backend systems with TypeScript and Node.js.
• Proven track record using AI coding tools to deliver production features and refactor complex codebases.
• Proven experience designing and building high-throughput distributed systems (e.g., handling 100K+ RPM).
• Strong understanding of microservices, event-driven architecture (Kafka), and transactional systems.
• Proficiency with SQL/NoSQL databases (MySQL/PostgreSQL, MongoDB) and leveraging Kubernetes in a cloud environment (GCP/AWS).

Good to Have

• Prior experience with Java, J2EE, or Ruby.
• Familiarity with complex e-commerce or marketplace platform logic.
• Knowledge of modern orchestration patterns (e.g., Temporal).
• Deep expertise in cloud infrastructure and services (GCP/AWS).

Groupon is a marketplace where customers discover new experiences and services everyday and local businesses thrive. To date we have worked with over a million merchant partners worldwide, connecting over 16 million customers with deals across various categories. In a world often dominated by e-commerce giants, we stand out as one of the few platforms uniquely committed to helping local businesses succeed on a performance basis.

Groupon is on a radical journey to transform our business with relentless pursuit of results. Even with thousands of employees spread across multiple continents, we still maintain a culture that inspires innovation, rewards risk-taking and celebrates success. The impact here can be immediate due to our scale and the speed of our transformation. We're a "best of both worlds" kind of company. We're big enough to have the resources and scale, but small enough that a single person has a surprising amount of autonomy and can make a meaningful impact.

About the Role

Join the CoreApps Platform team, the foundational engineering group at Groupon responsible for the global commerce engine. Our platform handles every customer interaction and transaction worldwide. This is a high-impact, senior-level Individual Contributor (IC) role with a dual mandate: ensuring KTLO stability at massive scale and accelerating a major platform modernization effort using an AI-first approach.

You will own mission-critical services that handle 100,000+ Requests Per Minute (RPM) and champion the shift from legacy Java/Ruby systems to a cutting-edge TypeScript/Node.js microservices architecture, leveraging state-of-the-art AI coding tools to achieve unprecedented speed and quality.

Key Responsibilities

• Architect and Develop high-throughput, low-latency Core Platform services (e.g., API Gateway, Deal Catalog, User Identity).
• Drive Modernization by actively refactoring and migrating critical services from legacy stacks to a modern TypeScript/Node.js microservices architecture.
• Champion AI-Assisted Development by leveraging AI coding tools (e.g., Copilot, Cursor) to accelerate feature delivery, navigate complex codebases, and mentor team members on best practices.
• Ensure Operational Excellence for global, production systems, including incident response, system resilience design (circuit breakers, retry logic), and participation in the on-call rotation.
• Design Distributed Systems that are fault-tolerant, self-healing, and resilient, including sophisticated caching and rate-limiting strategies.
• Own Complex Commerce Logic for financial systems, order management, and payment processing within the platform.

Key Requirements

• 6+ years of professional backend software development experience (or 3+ years with proven, exceptional AI-driven impact).
• Strong professional experience in building backend systems with TypeScript and Node.js.
• Mandatory: Proven track record using AI coding tools (e.g., Cursor, GitHub Copilot, Claude Code) to successfully deliver production features and refactor complex, multi-service codebases.
• Proven experience designing and building high-throughput distributed systems (e.g., handling 100K+ RPM).
• Strong understanding of microservices, event-driven architecture (e.g., Kafka), and transactional systems.
• Proficiency with SQL/NoSQL databases (MySQL/PostgreSQL, MongoDB) and leveraging Kubernetes in a cloud environment (GCP/AWS).

Nice to Have

• Prior experience with Java, J2EE, or Ruby (to aid in migration/refactoring).
• Familiarity with complex e-commerce or marketplace platform logic.
• Knowledge of modern orchestration patterns (e.g., Temporal).
• Deep expertise in cloud infrastructure and services (GCP/AWS).

What Success Looks Like

Success in this role means you will have become the technical anchor for a mission-critical platform component, such as the API Gateway or Deal Catalog. You will have demonstrably accelerated the platform modernization roadmap by 30% through the effective use of AI tools and have significantly improved the observability and resilience of the core services, reducing on-call incidents by at least 15%. You are the go-to expert for implementing scalable business logic and mentoring peers on AI-assisted practices.

We Are Interested In

An expert IC who is a pragmatic problem-solver, an AI champion, and a driver of both stability (KTLO) and transformation speed. We seek a candidate who can take full technical ownership and thrive in a high-stakes, evolving e-commerce environment.