Senior Software Engineer, Backend (AI)

We’re looking for a Senior Backend Engineer to join our newly formed AI R&D pod—a small, fast-moving team dedicated to building the future of AI-native product experiences at Posh. This is a backend-focused role with a strong emphasis on systems architecture and AI implementation. You will be responsible for building the intelligent, scalable, and reliable systems that power our AI features. Your work will focus on designing and deploying sophisticated Multi-Agent Systems, moving beyond simple RAG to create truly autonomous and helpful user experiences. You’ll work closely with frontend engineers and product designers to bring cutting-edge AI tools to our platform. Expect to build robust APIs, architect data flows for evaluations and fine-tuning, and pioneer new ways to leverage AI within our existing infrastructure. This represents a unique opportunity to build the foundational backend of our AI products, with the chance to ship experimental features to a large, growing, and highly engaged user base.