Senior Backend Engineer New York (3 days per week in office) We're working with a well-funded startup building a large-scale social platform from the ground up. The team is focused on creating the infrastructure needed to support millions of real-time interactions while laying the foundations for intelligent, AI-driven product experiences. As an early engineering hire, you'll have the opportunity to shape the architecture, influence technical decisions, and take ownership of core backend systems that will support the platform as it grows. The environment is fast-moving, collaborative, and operates on a hybrid model with three days per week in the New York office. The Role We're looking for a Backend Engineer with experience building distributed systems and high-traffic applications. You'll be responsible for designing and developing the services that power real-time user experiences, working across backend architecture, infrastructure, and data systems. Key Responsibilities • Design, build, and maintain backend services using TypeScript, Node.js, and NestJS • Develop scalable APIs and distributed services capable of handling large volumes of concurrent users • Build secure authentication and identity solutions using modern authentication standards • Design and implement event-driven architectures and real-time systems • Work across PostgreSQL, DynamoDB, Redis, and other data stores to ensure performance and reliability • Partner closely with the infrastructure team to improve scalability, deployment processes, and platform resilience within AWS • Support backend systems and data pipelines that power AI-enabled product features • Collaborate with a small engineering team, contributing to both architectural decisions and hands-on delivery Technical Requirements • Strong commercial experience with TypeScript, Node.js, and NestJS • Experience building and operating production-grade backend systems • Solid understanding of distributed systems, scalability, and system design • Experience building customer-facing platforms where performance, reliability, and uptime are critical