Scientist / Senior Scientist in Multimodal AI

Our MissionAt Altos Labs, we are dedicated to revitalizing cell health and resilience through innovative cell rejuvenation techniques to reverse disease, injury, and the disabilities that arise throughout life.Discover more about our vision at altoslabs.com.Our ValuesOur core value is simple yet powerful: Everyone Owns Achieving Our Inspiring Mission.Diversity at AltosWe understand that diverse perspectives are crucial for scientific breakthroughs and exploration. At Altos, exceptional scientists and industry leaders collaborate from around the globe to drive our shared mission forward. We prioritize a culture of belonging, ensuring that every employee feels valued for their unique contributions. We are all responsible for maintaining a diverse and inclusive workplace.Your Contributions to AltosJoin Altos Labs in creating a premier AI ecosystem aimed at addressing the most intricate challenges in human biology. You will be instrumental in designing and developing high-performance, scalable solutions that integrate high-dimensional biomedical imaging with molecular and linguistic data.Your role will involve implementing large-scale multimodal data fusion, advancing beyond basic image analysis to develop predictive models that span various biological domains. You will engage directly with data and coding, partnering with our engineering team to ensure these models are scalable, efficiently trainable in distributed cloud environments, and accessible to our global research network.Key ResponsibilitiesModel Development: Create, implement, and train large-scale foundational models (e.g., Vision Transformers, Multimodal LLMs) capable of embedding spatial data and integrating diverse modalities.Innovative Data Fusion: Apply cutting-edge cross-domain mapping and fusion techniques to align heterogeneous biological datasets.Scaling & Training: Develop and oversee high-performance ML pipelines designed to handle petabyte-scale image collections and multi-omics data streams in a cloud infrastructure.Technical Collaboration: Work closely with experimental scientists and software engineers to convert biological complexity into high-performance code and reliable distributed systems.Who You AreWe seek a technical expert who excels at unraveling "unsolvable" challenges through programming and meticulous experimentation. We welcome candidates at the Scientist I, Scientist II, or Senior Scientist levels.

Our MissionAt Altos Labs, we are dedicated to restoring cell health and resilience through innovative cell rejuvenation techniques aimed at reversing diseases, injuries, and disabilities that can arise throughout life.For further insights, please visit our website at altoslabs.com.Our ValueOur singular Altos Value is: Everyone Owns Achieving Our Inspiring Mission.Diversity at AltosWe firmly believe that diverse perspectives are crucial for scientific innovation. At Altos, exceptional scientists and industry leaders collaborate globally to further our shared mission. We prioritize Belonging, ensuring all employees feel valued for their unique perspectives, and we hold ourselves accountable for maintaining a diverse and inclusive environment.Your Contributions to AltosAs a member of our team, you will accelerate and enhance our efforts in developing unified, multi-modal generative foundation models tailored for multiscale biology. You will be a key player in multidisciplinary teams that create the computational platforms essential for Altos to fulfill its mission.In this position, you will collaborate with other scientists and engineers across the Institute of Computation to design, develop, and scale cutting-edge foundation models that address biological inquiries and assist in discovering novel interventions for aging and disease. Your focus will be on synthesizing unstructured multimodal signals with structured relational data and knowledge graphs that depict biological realities.The ideal candidate will excel in a dynamic environment that values teamwork, transparency, scientific excellence, originality, and integrity.

At Descript, we are on a mission to revolutionize the way audio and video content is created. Our innovative platform has earned the trust of renowned podcasters, influencers, and prestigious organizations like BBC, ESPN, HubSpot, Shopify, and The Washington Post. With $100M in funding from top investors, including the OpenAI Startup Fund, Andreessen Horowitz, Redpoint Ventures, and Spark Capital, we are poised for tremendous growth. We are seeking a proactive and analytical Senior Marketing Data Scientist to join our dynamic Growth team. In this role, you will collaborate with the Performance Marketing team to design and implement a comprehensive measurement framework, optimize marketing performance across the entire funnel, and drive data-informed business strategies. This crucial position will enable Descript to enhance its marketing capabilities across both B2C and B2B sectors. You will leverage AI-driven analytics tools to streamline decision-making processes and deliver scalable predictive insights. This position can be performed remotely within the United States or onsite in the San Francisco Bay Area.

Join the dynamic Analytics team at DoorDash as a Data Scientist or Senior Data Scientist, where your expertise will directly influence strategic decisions and operational improvements. You will uncover valuable insights from vast datasets, transforming them into actionable recommendations that drive company-wide initiatives. Collaborate with diverse teams in areas like Consumer & Growth, Business Operations, and Customer Experience to elevate our analytics capabilities and impact our business in meaningful ways.

Join Demandbase as an Applied AI Scientist, where you'll have the opportunity to push the boundaries of AI technology in a dynamic and innovative environment. As a key member of our team, your role will involve developing and implementing advanced AI solutions that drive impactful business results.We're looking for a passionate individual who thrives on solving complex problems and is eager to contribute to AI advancements. You will collaborate with cross-functional teams to integrate AI models into our existing frameworks and enhance our product offerings.

About FaireFaire is revolutionizing the wholesale marketplace, advocating for local businesses by connecting independent retailers worldwide. We believe in the power of local entrepreneurship, where independent shops can thrive and compete against giants like Walmart and Amazon. Our innovative technology, data analytics, and machine learning empower these businesses to discover unique products that resonate with their communities. By supporting local economies, we are committed to driving positive change globally. Join us in our mission to empower local businesses and make a difference!About this RoleAs a vital member of our Ads Data team, you will play a crucial role in developing cutting-edge advertising solutions for the wholesale sector. You will influence the design and functionality of our auction system, focusing on bidding strategies, pacing, pricing, and budget optimization. Utilizing our proprietary conversion data, you will train models that yield significant business outcomes for our partners. This is an exceptional opportunity to make a substantial impact in a rapidly growing division that is a key strategic focus for Faire.Collaborating with engineers, product managers, and designers, you will contribute to systems that not only demonstrate technical sophistication but also enhance profitability for both our brands and Faire.

About Retell AI Retell AI develops advanced voice AI technology for call centers, using first-principles approaches to create intelligent voice agents. These agents help businesses manage sales, support, and logistics communications while reducing reliance on large human teams. The company has reached $36M ARR in just 18 months, backed by Y Combinator and Alt Capital. With a team of 20, Retell AI is building a comprehensive customer experience platform, aiming for AI-powered contact centers by 2026. The vision: intelligent agents that execute, monitor, and improve customer interactions with minimal human oversight. Named a top 50 AI app by a16z: https://tinyurl.com/5853dt2x Ranked #4 on Brex's Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025 Featured among top startups: https://leanaileaderboard.com/ Role Overview: Research Scientist - Voice AI Innovation This role centers on advancing machine learning for human-like voice agents in real-world settings. The Research Scientist will explore new methods in large language models (LLMs) and audio models, design evaluation techniques, and prototype systems that improve reasoning, reduce latency, and enhance conversational quality. The work involves open-ended ML challenges, rapid experimentation, and direct influence on the performance and cognitive abilities of voice AI systems at scale. Location San Francisco Bay Area

Join Oura as a Staff AI Scientist, where you will be at the forefront of developing innovative AI solutions that enhance our health and wellness technology. You will collaborate with a talented team of data scientists, engineers, and domain experts, leveraging the latest advancements in artificial intelligence to drive impactful outcomes. This is an exciting opportunity to shape the future of health technology in a dynamic and supportive environment.

We are seeking a highly motivated and talented Senior Associate Scientist to join our dynamic team in San Francisco. In this role, you will collaborate with cross-functional teams to advance our scientific initiatives and contribute to groundbreaking research. You will have the opportunity to work with cutting-edge technologies and methodologies, driving innovation within our organization.

Join the Center for AI Safety (CAIS), a premier research and advocacy organization dedicated to addressing the complex societal challenges posed by artificial intelligence (AI). Our mission focuses on mitigating large-scale risks associated with AI through groundbreaking technical research, strategic initiatives, and proactive policy engagement, in collaboration with our sister organization, the Center for AI Safety Action Fund. As a Senior Research Scientist at CAIS, you will spearhead and execute transformative research aimed at enhancing the safety and reliability of advanced AI systems. You will take ownership of significant open challenges, driving them to successful publication. We seek individuals who set a high standard for research excellence and contribute innovative ideas to elevate our collective understanding. Your role will involve designing and conducting experiments on large language models, developing the necessary tools for large-scale model training and evaluation, and translating findings into publishable research. Close collaboration with CAIS researchers and external academic and industry partners will be essential, utilizing our compute cluster for extensive training and evaluation projects. Research areas include AI honesty, robustness, transparency, and mitigating trojan/backdoor behaviors, all geared towards reducing real-world risks from sophisticated AI systems.

AI Research ScientistAt Substrate, we are tackling a critical technological challenge that impacts the United States. Positioned at the crossroads of advanced manufacturing and innovative physics, our mission is to develop transformative technologies that will revolutionize the semiconductor industry and bolster America's technological dominance. Our team comprises top-tier scientists, engineers, and technical specialists dedicated to pushing the boundaries of technology for the benefit of the nation.As an AI Research Scientist, you will play a key role in enhancing and accelerating research and development processes by harnessing machine learning techniques for scientific simulations and modeling. You will also focus on establishing internal AI capabilities throughout our organization. This position merges cutting-edge physics with artificial intelligence, requiring hands-on development of AI-enhanced tools that facilitate groundbreaking research. You will also contribute to building the infrastructure and expertise required for our technical teams to effectively use AI in their workflows. Whether you are a physicist who has adopted machine learning or an AI expert with a solid scientific background, you will be instrumental in shaping our approach to utilizing AI to expedite our internal R&D efforts.

AI Research ScientistOverviewJoin Physical Superintelligence, an innovative startup rooted in prestigious institutions such as Harvard, MIT, Johns Hopkins, Oxford, the Institute for Advanced Study, and the Perimeter Institute. We are at the forefront of building AI systems designed to uncover groundbreaking insights in physics on a grand scale. We are in search of talented AI researchers dedicated to developing reinforcement learning agents and training frameworks that propel scientific discovery.Key Responsibilities- Develop and optimize AI systems aimed at physics discovery, collaborating with physicists on verification harnesses and engineers on training infrastructure.- Address critical AI research questions related to agent learning in physics reasoning, action space design for scientific exploration, reward structure development, and scalable training systems.- Construct and train reinforcement learning agents leveraging cutting-edge methodologies such as PPO, SAC, MuZero, and multi-agent self-play.- Design agent architectures tailored for physics reasoning and scientific tool utilization.- Execute training curricula and reward structures for discovery tasks.- Establish evaluation workflows and benchmarks to assess physics reasoning capabilities.- Develop instrumentation to analyze agent behavior and learning dynamics.- Collaborate closely with physicists and engineers to refine system design and architecture.Candidate ProfileWe are looking for candidates with a strong background in developing agents and training models using reinforcement learning. Proficiency in modern machine learning frameworks and experience with distributed training systems is essential, alongside a proven track record of deploying effective AI systems.Essential Skills:- Practical experience with contemporary reinforcement learning algorithms including PPO, SAC, MuZero, and multi-agent self-play.- Proficient in PyTorch or JAX, with hands-on experience in distributed training using Ray, XLA, or Accelerate, and familiarity with modern pretraining workflows.Preferred Background:- A strong foundation in physics or mathematics that enhances intuition for physical reasoning and mathematical modeling.- Experience applying agents in simulators, games, scientific tool use, or benchmark design employing rigorous experimental methodologies.

Vivodyne: Pioneering Human Data Generation Pre-Clinical TrialsAt Vivodyne, we revolutionize the discovery, design, and development of human therapeutics by utilizing large-scale, lab-grown human organ tissues. Our innovative approach integrates cutting-edge biology, robotics, and artificial intelligence, allowing us to identify and validate novel therapeutic targets while minimizing risks associated with new therapeutic assets. By generating clinically translatable multi-omic data from our proprietary human organ tissues, we produce more human data than all U.S. clinical trials combined. Backed by elite venture funds, we collaborate with leading multinational pharmaceutical companies to enhance drug discovery and significantly reduce animal testing burdens.www.vivodyne.comRole OverviewThe AI Team at Vivodyne faces some of the most compelling challenges in science and engineering. With access to extensive and rich human tissue imagery, we are pushing the boundaries of artificial intelligence in biological applications. We are developing a suite of AI technologies aimed at automating the discovery, development, and de-risking of novel therapies through our unique technology platform, including single-cell 3D phenomics/machine vision, multimodal (multi-omic) translation, and reinforcement learning for robotic planning and study design.As an AI Senior Scientist, you will apply your expertise in large-scale model development (including Transformer, Diffusion, and hybrid architectures) and Generative AI solutions to transform our advanced imaging and multi-omics datasets into groundbreaking scientific insights. You will work closely with biologists, engineers, and AI specialists to create robust, production-ready algorithms and models that facilitate Vivodyne's impactful discoveries.This position requires on-site work at our Brisbane, California office.

Role overview Pinterest is hiring a Senior Data Scientist for its Responsible AI team. This position focuses on building AI systems that prioritize ethics and fairness. The work involves applying advanced statistical methods and machine learning to support responsible technology development. What you will do Develop and refine AI models with an emphasis on ethical outcomes and fairness Apply statistical analysis and machine learning algorithms to real-world product challenges Work closely with teams across engineering, product, and policy to align AI technologies with Pinterest’s standards for user trust and responsibility Location This role is based in San Francisco, CA, or can be performed remotely within California.

Join Plaid as a Senior Data Scientist specializing in Data Foundations and AI. In this pivotal role, you will leverage your expertise in machine learning and data analysis to drive innovations that enhance our core data products. Collaborating with cross-functional teams, you will create solutions that empower our clients and improve user experiences.

About Retell AI Retell AI builds voice AI technology that helps businesses transform their call center operations. In just 18 months, thousands of companies have adopted Retell’s AI voice agents to streamline sales, support, and logistics, work that once required large human teams. Backed by investors including Y Combinator and Alt Capital, Retell has grown annual recurring revenue from $5M to $36M with a focused team of 20. The company’s goal for 2026: a modern customer experience platform where AI powers entire contact centers. Retell is developing AI “workers” that can serve as frontline agents, quality assurance analysts, and managers, handling, evaluating, and improving customer interactions on their own. Named a top 50 AI app by a16z: https://tinyurl.com/5853dt2x Ranked #4 on Brex’s Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025 Featured on the Lean AI Leaderboard: https://leanaileaderboard.com/ Role Overview: Research Scientist – LLM Retell AI is hiring a Research Scientist focused on large language models (LLMs) and audio processing. This role suits machine learning researchers who want to push the boundaries of real-time AI and see their work in production. What You Will Do Investigate new approaches in large language models and audio processing for human-like voice agents Design and implement evaluation methods for complex, real-world conversational systems Prototype systems to improve reasoning, reduce latency, and enhance conversation quality Work closely with engineering and product teams to bring research advances into production Impact Research at Retell directly shapes the capabilities of voice AI agents for thousands of businesses. The work blends advanced research with practical deployment, improving how customers interact with automated systems across industries. Location This position is based in the San Francisco Bay Area.

About the Role Grow Therapy is hiring a Senior or Staff Data Scientist in San Francisco. This role focuses on using data to inform key decisions and improve therapy services.

About FaireFaire is a revolutionary online wholesale marketplace that champions the belief that the future of retail is local. Independent retailers worldwide generate more revenue collectively than giants like Walmart and Amazon, yet they often lack the resources to compete. At Faire, we leverage cutting-edge technology, data analytics, and machine learning to empower this vibrant community of entrepreneurs globally. Imagine your favorite local boutique — we facilitate their access to exceptional products from around the globe. By providing the right tools and insights, we aim to level the playing field, enabling small businesses everywhere to thrive against e-commerce giants.By nurturing the growth of independent businesses, Faire is making a significant economic impact in local communities, worldwide. We seek intelligent, resourceful, and passionate individuals to join us in driving the shop local movement. If you believe in the power of community, we invite you to become a part of ours.About this RoleAs a Senior Applied AI/ML Scientist within the Search group, you will play a pivotal role in shaping the technical vision and machine-learning strategy that drives one of our core growth areas: Search. You will enhance real-time Search and Recommendation systems that deliver next-generation shopping experiences.You'll be at the forefront of algorithm development, integrating large language models, natural language processing, query understanding, deep learning, transformer-based sequential modeling, graph neural networks, and structured behavioral data to return hyper-relevant, personalized product suggestions for every user query.This is a unique opportunity to influence end-to-end personalization in a high-scale, multi-modal environment while collaborating closely with a talented team of scientists and engineers.

At Sciforium, we are at the forefront of AI infrastructure, creating next-generation multimodal AI models and a proprietary high-efficiency serving platform. With substantial backing from AMD, our team is rapidly expanding to develop the complete stack necessary for cutting-edge AI models and real-time applications.About the RoleWe are on the lookout for a talented Senior Research Scientist with expertise in advanced AI and machine learning. This role entails spearheading innovative research projects focusing on large language models, generative media, model architecture, optimization, and scalable training systems. You will engage directly with contemporary ML frameworks, publish original research, and collaborate closely with engineering teams to transition impactful models into production. This position is perfect for a driven researcher excited about pioneering breakthroughs in AI.What You'll DoLead research initiatives in advanced machine learning topics such as LLMs, generative AI, foundational modeling, optimization strategies, diffusion models, and novel Transformer architectures.Design, implement, and assess new ML algorithms using frameworks like PyTorch and JAX.Conduct large-scale distributed training experiments utilizing multi-GPU/TPU systems and cutting-edge compute infrastructure.Enhance performance through debugging frameworks, optimizing speed, and refining training pipelines.Generate high-quality research outputs including academic papers, internal reports, patents, and reproducible code.Work collaboratively with engineering and product teams to convert research prototypes into robust production systems.Stay updated with the latest research advancements to incorporate state-of-the-art techniques into Sciforium's AI roadmap.Mentor junior researchers and actively contribute to fostering a world-class AI research culture.

Join our innovative team at Pinterest as a Senior Data Scientist in the Core division. We're looking for a data-driven professional who is passionate about leveraging data analytics and machine learning to enhance user experience and drive business outcomes. At Pinterest, you will collaborate with cross-functional teams to develop data models and insights that influence strategic decisions.