[Remote] Mojo Libraries Engineer

Note: The job is a remote job and is open to candidates in USA. Modular is on a mission to revolutionize AI infrastructure by rebuilding the AI software stack. As a Mojo Libraries Engineer, you will design and implement core abstractions across the Mojo Standard Library and kernel libraries, empowering developers to integrate with AI systems and accelerate innovation. Responsibilities • Partner with teams across Modular—including compiler, kernel, and runtime engineers—to design APIs that are ergonomic, expressive, and performance-conscious. Your work will directly shape the developer experience and deliver high business impact by enabling critical customer workloads and accelerating platform adoption. • Design and implement abstractions that enable the development and optimization of kernels and algorithms running on GPUs and CPUs, delivering top-tier performance and accuracy throughout the GenAI inference solution stack. • Optimize library functionality for performance, memory efficiency, and hardware utilization. • Participate in design discussions and code reviews to uphold high engineering standards. • Collaborate with other engineering teams to align the standard library with broader platform needs. • Contribute to a fully open source project — everything you build will be public and part of our GitHub repo. • Engage with the open source community to support high-quality contributions and foster a welcoming, inclusive environment. Skills • Experience with GPU programming languages like CUDA or OpenCL. • Deep understanding of GPU architecture (memory hierarchies, tensor cores, etc.) and how it influences algorithm and API design. • Proficiency in modern systems languages (C++, Rust, or Swift), with strong skills in low-level programming, performance optimization, and memory management. • Passion for both library design and performance, with a commitment to following modern API patterns and language evolution in C++, Rust, and Swift ecosystems. • Hands-on open source experience — either through meaningful contributions or by maintaining and reviewing community submissions. • A collaborative mindset, intellectual curiosity, and drive to solve complex technical challenges as part of a high-performing team. • Strong alignment with Modular's cultural values and enthusiasm for building a thoughtful, inclusive engineering culture. • Familiarity with GPU assembly languages such as PTX and SASS. • Knowledge of cutting-edge APIs such as CUTLASS or Triton. • Prior experience with Mojo, especially with accepted contributions to the Mojo Standard Library. • Familiarity with LLVM, MLIR, or Python, particularly in systems or compiler-related contexts. • An advanced degree in Computer Science or a related field. Benefits • Premier insurance plans • Up to 5% 401k matching • Flexible paid time off • Stock options • Annual target bonus • Equity Company Overview • Modular provides AI infrastructure for deployment, serving, and programming GPUs. It was founded in 2022, and is headquartered in Palo Alto, California, USA, with a workforce of 51-200 employees. Its website is Company H1B Sponsorship • Modular has a track record of offering H1B sponsorships, with 10 in 2025, 6 in 2024, 8 in 2023, 4 in 2022. Please note that this does not guarantee sponsorship for this specific role. Apply tot his job