Senior Backend Engineer

Gen OS (Headquarters: Remote)

Python ML AI Scalability System Performance Hybrid Search Data Pipelines Vector Databases Swift Rust OS Concurrency Typescript Java C++ Concurrency Data Retrieval Knowledge Graph RAG Back End Engineer Staff Engineer

Gen OS is a seed-funded team (~$5m) building LittleBird, a digital twin that understands you: what you care about, what you want to accomplish, the people in your life, your near and long term goals, for Mac + Android. The team is remote-first, with teammates in the Bay Area, NYC, Europe & India. Our team is well-funded >$4m, small and growing. Our co-founders have experience building data, consumer hardware, and interactive products, including selling a previous venture for >$250m. We are seeking a Senior Backend Engineer to join our fast-paced team and play a crucial role in designing, developing, and implementing new features for Littlebird, our personalized AI teammate for Mac and Android. This position reports directly to the technical leadership team and will be instrumental in shaping critical backend features and infrastructure as we scale. Key Responsibilities: - Work closely with R&D and Leadership to design scalable architecture. - Develop and maintain high-throughput backend services that support AI features including search, informational retrieval, RAG, and Knowledge Graph. - Build systems with a strong focus on performance, accuracy, and scalability. - Understand and enforce security best practices across our infrastructure. Required Skills & Experience: - Minimum of 4 years of hands-on software development experience with strong professional experience in Python, and one other language from the following: Typescript, Rust, Java, or C++. - A passion for working on complex problems involving concurrency, internet-scale data retrieval, and performance tuning. - Ability to autonomously work on weakly defined projects that require an experiment-driven and collaborative mindset. - Excellent verbal and written communication skills. Desired Experience: - Prior startup experience, especially shipping products from 0-1 and/or owning major parts of a production-grade codebase. - Experience leading architectural discussions, evaluating tradeoffs, and designing comprehensive integrations and test plans. Ideal Candidate: The ideal candidate is a proactive and collaborative Senior Backend Engineer who thrives in a fast-paced, remote-first environment. You should be excited about contributing to foundational aspects of a growing AI product and be passionate about building high-performance, scalable systems that support cutting-edge AI features. Your strong technical background in Python and experience with complex system design will be key to your success. Benefits: Benefits include a remote-friendly work environment, a collaborative team culture, opportunity to shape infrastructure decisions, competitive compensation packages (including stock, health/dental/vision/life benefits, paid time off, 401k, and parental leave), and flexible working hours across multiple time zones.