Creating revolutionary open-ended conversational applications through breakthrough research.

Character.AI

Research Engineer, ML Systems (All Industry Levels)

Software Engineer, Machine Learning Infrastructure

Staff Software Engineer, Applied ML

Product Manager, Engagement

Data Scientist, Product

UX Researcher

Ello

Product Engineer (Mobile)

ElevenLabs

Performance Marketing Lead

Ello seeks a Product Engineer (Mobile) to bridge design and engineering, focusing on seamless mobile front-end experiences.  Responsibilities include developing and integrating front-end components using React & Flutter, owning features end-to-end, acting as a liaison between design and engineering, building new components, and managing production workflows.  The ideal candidate possesses strong UI/UX design skills, mobile development experience (Flutter or native Android), and a computer science/engineering background.  They'll bring Ello's AI tutoring to life through character development and game interactions, ensuring engaging and educational experiences for children.

The world’s first AI reading coach that works with real books.

Tech Lead, Machine Learning

Senior Mobile Engineer (Flutter)

Senior Designer, New Products

Design Engineer (Mobile)

<div class="_descriptionText_4fqrp_201">Engineering, full-timeSan Francisco (Relocation assistance available)Salary range: $140,000 - $210,000 + EquityAt Ello, our mission is to maximize the potential of all children. Our first product, Read with Ello, is an AI reading teacher that listens to children read out loud. Ello uses speech recognition to help them when they get stuck, makes up stories using generative AI, and inspires a love for reading.We’re now building on the success of Read with Ello and putting together the pieces of the world’s first complete AI teacher for all children. Together, we believe we can close the primary school education gap worldwide.Ello has been recognized on Fortune’s “Change the World” and Time’s 2024 Best Inventions lists. We are well-funded, backed by world-class investors, and ready to recruit new talent to help us achieve our vision.Who you’ll be joiningEllo is a rapidly growing, series A startup focused on revolutionizing the way children learn and interact with technology. You will work directly with Ello’s Co-founder &amp; CTO, Catalin Voss, on a small team (&lt;10) of engineers, learning designers, and PMs to develop new products. We work in-person out of our San Francisco office and we’re big believers in face-to-face collaboration.About the roleWe’re looking for a Product Engineer to bridge the gap between design and engineering, focusing on creating seamless front-end experiences on mobile platforms. You will own feature development from start to finish, at times acting as your own product manager, and collaborating closely with product and engineering teams. You don’t need to be an illustrator, but you’re able to take an existing component library and build new frontend tools from scratch on the frontend (React &amp; Flutter) without a designer. You’re responsible for bringing Ello’s tutoring AI to life through character development and game interactions. You pay attention to the details. You want to build products that delight users.We welcome candidates from both design and engineering backgrounds, but we prioritize strong technical foundations and demonstrated execution speed.Responsibilities<ul style="min-height:1.5em"><li>Develop and integrate front-end components for mobile and web platforms, leveraging existing design systems and brand guidelines.</li><li>Own features end-to-end, from concept to delivery</li><li>Serve as a bridge between design and engineering, moving fluidly between UX/UI and technical problem-solving.</li><li>Build new components and maintain consistency within the app.</li><li>Set up basic infrastructure, manage production workflows, and handle continuous integration and app store delivery/release processes.</li></ul> Required Experience<ul style="min-height:1.5em"><li>Design:<ul style="min-height:1.5em"><li>Proven UI/UX design skills, with experience across both mobile and web interfaces</li><li>Very high level of attention to detail. For example, you see how small changes in a character’s facial expression or the shading of a background affect the emotional impact of the end product</li><li>Demonstrated ability to work within existing design systems and brand standards to build new front-end components</li><li>Cross-functional skills, having either picked up engineering from a design domain or design skills from a computer science background</li></ul></li><li>Engineering:<ul style="min-height:1.5em"><li>Experience with object-oriented programming and production-grade mobile development</li><li>Computer science/engineering background or equivalent extensive front-end engineering experience</li><li>Knowledge of front-end development platforms (web and mobile)</li><li>Understanding of mobile app architecture, design patterns, and performance optimization techniques</li><li>Experience with Flutter or native Android development in Java/Kotlin</li><li>Familiarity with Git flow, basic infrastructure setup, and production workflows</li><li>Exposure to continuous integration, app store delivery, and release processes</li><li>Exposure to agile development methodologies and project management tools, version control systems, and collaborative development tools</li></ul></li></ul> Nice to have experience<ul style="min-height:1.5em"><li>Experience as a product manager or in a role with significant ownership over features or components.</li><li>Experience with game development</li><li>Experience with generative AI applications</li><li>Experience with designing products for children</li></ul>We look for candidates who<ul style="min-height:1.5em"><li>Have something to teach us</li><li>Want to do work they are proud of to ship products they are proud of</li><li>Have an urge to make a real impact on child development at scale</li><li>Take initiative and full ownership of their work</li><li>Prefer open and direct communication grounded in empathy to beating around the bush</li><li>Exemplify integrity in their actions, decisions, and communication</li><li>Want to build meaningful relationships at work</li></ul>Here are some reasons to be a part of our team<ul style="min-height:1.5em"><li>Immerse yourself in a collaborative environment surrounded by an A+ team</li><li>Dive deep into the rapidly evolving world AI and interactive learning.</li><li>Experience the joy of turning your designs and code into engaging and educational experiences for children worldwide.</li><li>Work in tandem with our engineering teams to harness the full power of technology to reimagine education.</li></ul>About ElloEllo is a public benefit corporation on a mission to maximize the potential of all children. We’re currently around 45 people, headquartered in San Francisco, with offices in São Paulo, Brazil; Nairobi, Kenya; and New York.Our team has deep expertise in artificial intelligence, K-12 education, and child development across institutions such as Stanford, Berkeley, Google, Apple, and more. We were part of Y Combinator’s W20 batch and are funded by world-class investors including Goodwater Capital, Homebrew, Reed Hastings, Common Sense Growth, Ravensburger, Project A Ventures, Reach Capital, Khosla Ventures, WndrCo, Visible Ventures, and K9 Ventures.We’re a small, collaborative team that takes each other’s voices very seriously. Because our mission is to support all children, it is critical that our team is representative of the communities we work in; we place significant emphasis on ensuring diversity in our team and inclusion in our culture.We feel enormously privileged to be one of the few companies that has the opportunity to take a shot at truly revolutionizing education with AI at this inflection point in technology. We don’t take it for granted, so we work quite hard to turn that vision into reality with urgency. We want to create an environment in which we can all be our best selves, use our strengths to take Ello forward, and develop our own skills. We want to have fun while working hard to do impactful things that we’re proud of – and we believe it’s possible to do both.At Ello, we view diversity as a moral imperative and a competitive advantage. We do not discriminate on the basis of race, religion, skin color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. We plan and structure our interviews to directly assess skills and experience. If you need any accommodations throughout the interview process, please reach out to jackie@ello.com.Compensation Range: $140K - $210K</div>

As a Research Engineer on the ML Systems team at Character.AI, you'll optimize the performance and efficiency of GPU clusters, develop new technologies to fine-tune leading consumer AI models, and serve 20K+ QPS in production with LLMs.  Responsibilities include writing efficient Triton kernels, developing prefix-aware routing algorithms, training and distilling LLMs, building a scalable distributed RLHF stack, and developing systems for efficient multimodal model training and inference. Your work will directly impact millions of users daily, shaping the future of conversational AI.

<div class="_descriptionText_4fqrp_201">Joining us as a Research Engineer on the ML Systems team, you’ll be working on cutting-edge ML training and inference systems, optimizing the performance and efficiency of our GPU clusters, and developing new technologies that fine-tune leading consumer AI models with a data flywheel, and serve 20K+ QPS in production with LLMs. Your work will directly contribute to our groundbreaking advancements in AI, helping shape an era where technology is not just a tool, but a companion in our daily lives. At <a target="_blank" rel="noopener noreferrer nofollow" href="http://Character.AI">Character.AI</a>, your talent, creativity, and expertise will not just be valued—they will be the catalyst for change in an AI-driven future.<h2>About the role</h2>The ML Systems team is responsible for the research and deployment of systems that efficiently utilize GPU for AI-enabled products.&nbsp;As a research engineer, you will work across teams and our technical stack to improve our training performance and inference runtime. You will get to shape the conversational experience of millions of users per day.Example projects:<ul style="min-height:1.5em"><li>Write efficient Triton kernels and tune them for our specific models and hardware</li><li>Develop prefix-aware routing algorithms to improve serving cache hit rate</li><li>Train and distill LLMs to improve latency while preserving accuracy and engagements</li><li>Build an efficient and scalable distributed RLHF stack powering the model innovations</li><li>Develop systems for efficient multimodal (image gen/video gen) model training &amp; inference</li></ul><h2>Job Requirements</h2><ul style="min-height:1.5em"><li>"All Industry Levels": at least PhD (or equivalent) research experience</li><li>Write clear and clean production system code</li><li>Strong understanding of modern machine learning techniques (reinforcement learning, transformers, etc)</li><li>Track record of exceptional research or creative ML systems projects</li><li>Comfortable writing model development code (PyTorch) for either training or inference</li></ul><h2>Nice to Have</h2><ul style="min-height:1.5em"><li>Experience training large models in a distributed setting utilizing PyTorch distributed, DeepSpeed, Megatron.</li><li>Experience working with GPUs &amp; collectives (training, serving, debugging) and writing kernels (Triton, CUDA, CUTLASS).</li><li>Experience with LLM inference systems and literature such as vLLM and FlashAttention.</li><li>Familiarity with ML deployment and orchestration (Kubernetes, Docker, cloud)</li><li>Publications in relevant academic journals or conferences in the field of machine learning and systems</li></ul><h2>About Character.AI</h2>Founded in 2021, Character is a leading AI company offering personalized experiences through customizable AI 'Characters.' As one of the most widely used AI platforms worldwide, Character enables users to interact with AI tailored to their unique needs and preferences.In just two years, we achieved unicorn status and were named Google Play's AI App of the Year – a testament to our groundbreaking technology and vision.Ready to shape the future of Consumer AI? 🚀 At Character, we value diversity and welcome applicants from all backgrounds. As an equal opportunity employer, we firmly uphold a non-discrimination policy based on race, religion, national origin, gender, sexual orientation, age, veteran status, or disability. Your unique perspectives are vital to our success.Compensation Range: $225K - $400K</div>