Backend Engineer

About the Role

We're looking for a backend engineer who can architect and scale AI-native infrastructure that powers both real-time video generation and a two-sided marketplace. You'll own critical systems — from orchestrating complex video processing workflows with multiple AI models to building GraphQL APIs that serve millions of personalized media assets. This is a highly technical role where performance, reliability, and elegant system design all matter. You'll work closely with ML teams to integrate cutting-edge generative models into production-ready APIs, and with frontend teams to deliver seamless real-time experiences across web and mobile.

What You'll Do

• Build and maintain a high-performance GraphQL API with real-time subscriptions for video generation status, messaging, notifications, and live feeds

• Architect video processing pipelines that orchestrate FFmpeg, multiple AI model APIs (OpenAI, Anthropic, FAL), and AWS services for transcoding, thumbnail generation, and content moderation

• Design scalable workflows for AI agent conversations, personalized video generation, and multi-step remix operations using CQRS patterns

• Integrate and optimize real-time AI model APIs with proper error handling, retry logic, rate limiting, and cost optimization across multiple providers

• Implement robust billing and payment systems with Stripe, including credit management, usage tracking, and subscription handling

• Build vector search and recommendation systems using Turbopuffer for semantic video discovery and content matching

• Optimize database queries and indexing in MongoDB for complex aggregations across users, follows, likes, comments, and video metadata

• Design and implement caching strategies using Redis for session management, rate limiting, and high-traffic read operations

• Ensure system reliability with proper monitoring (Sentry), structured logging (Pino), and observability across distributed services

What We're Looking For

Required:

• Proven experience building and shipping production Node.js/TypeScript applications at scale (consumer-facing products preferred)

• Strong expertise in NestJS or similar opinionated frameworks (Express, Fastify, Koa with dependency injection patterns)

• Deep understanding of GraphQL including schema design, resolvers, subscriptions, and performance optimization (N+1 queries, DataLoader patterns)

• Experience with MongoDB and document-based data modeling for social/UGC platforms

• Proficiency in video/media processing with FFmpeg or similar tools (transcoding, thumbnails, format conversion)

• Experience integrating third-party APIs (AI models, payment processors, cloud services) with proper error handling and monitoring

• Strong systems thinking around caching, queueing, rate limiting, and async job processing

• Familiarity with AWS services (S3, CloudFront, or similar cloud infrastructure)

Bonus:

• Experience with real-time systems (WebSockets, Server-Sent Events, GraphQL subscriptions)

• Knowledge of vector databases and semantic search (Pinecone, Weaviate, Turbopuffer)

• Experience with LLM integration and prompt engineering in production systems

• Familiarity with CQRS/Event Sourcing patterns for complex domain logic

• Experience with content moderation and trust & safety systems

• Knowledge of Stripe or similar payment platforms for SaaS/marketplace products

• Interest in generative AI, creator tools, or two-sided marketplaces

Why Join Us

We're building a new kind of media company — one that combines creative freedom with cutting-edge ML. You'll join a team of ex-founders, ICML-published researchers, and builders from unicorn startups and top UGC platforms, backed by Andreessen Horowitz SR04 and top angels across the video AI space. We're still early, and this is your chance to shape both the technology and the culture from day one. You'll be working on systems that process millions of video generations, power real-time creator workflows, and enable entirely new forms of AI-native advertising.