Backend Engineer

## About the role - Agentic Workflows: Build the orchestration layer that lets TwinMind decide what it needs (memory lookup, calendar check, web search, or nothing), fetch it, and weave it into a natural response, all within the latency budget of a live conversation. - Evaluation: Build and maintain evaluation suites that measure response quality, memory retrieval accuracy, and persona consistency across rapid product updates. - Backend Systems: Design and ship the APIs, data pipelines, and services that power memory retrieval, context assembly, and LLM orchestration. - Infrastructure: Own the internal frameworks for prompt versioning, A/B testing, and deployment so the team can iterate on AI behavior with confidence. - Cross-functional Collaboration: Partner with iOS, Android, and product teams to ship new features end-to-end, from proactive suggestions to new memory integrations. ## Required Qualifications - 4+ years of backend software engineering experience (Python, Go, Java, or similar), including designing APIs, working with databases, and building services that run in production. - Demonstrated hands-on experience with LLMs, and agentic workflows (tool use, routing, context management) through industry work, research, or significant personal projects. - Strong understanding of evaluation methodologies and metrics for generative AI systems. - Can write a clear prompt spec or system design doc that both engineers and non-technical stakeholders can follow. ## Preferred Qualifications - Deep experience with Retrieval-Augmented Generation (RAG) and managing long-term memory systems for AI. - Background in Machine Learning, NLP, or related fields. - Experience with A/B testing and experimentation frameworks in a production environment. - Track record of improving AI system performance and latency through systematic evaluation and iteration. ## You Might Thrive in This Role If You… - Love the craft of making language models behave and can find creative ways to make them contextually aware. - Want to be at the intersection of AI capability and product experience, not just one side. - Are comfortable with ambiguity and can independently define success metrics for novel AI features. - Can manage multiple concurrent projects and prioritize ruthlessly in an unstructured, fast-moving environment. - Have a strong founder's mentality: you take extreme ownership and drive projects from conception to production. - Are passionate about building AI systems that are genuinely helpful and seamlessly integrated into users' daily lives. ## About the company We're on a mission to make every human superintelligent. Our first product is a personalized "second brain"—an AI twin powered by everything you see and hear, that learns with you, remembers your entire life, and helps proactively before you even ask. Our co-founders are AI scientists who have built moonshots at Google X, deployed production systems with over $1 billion revenue impact on Wall Street, and contributed to a Nobel Prize-winning discovery. We have raised funding from some of Silicon Valley's most influential venture capitalists, including the earliest investors in Facebook, Robinhood, and Zapier. ## Location Menlo Park, California ## Benefits - Unlimited PTO - Health Insurance