Senior Machine Learning Engineer at Retell AI | San Francisco Bay Area

About Retell AIAt Retell AI, we are pioneering the future of call centers through innovative voice AI technology. Our cutting-edge solutions are transforming how companies engage with customers.In just 18 months since our inception, we've empowered thousands of businesses with our AI voice agents that efficiently manage sales, support, and logistics calls, significantly reducing the need for large teams of human agents. Supported by industry-leading investors including Y Combinator and Alt Capital, we've grown our annual recurring revenue from $5M to an impressive $36M while expanding our team from 5 to 20 talented individuals since 2025.Our ambitious vision for 2026 is to develop a state-of-the-art customer experience platform where entire contact centers are driven by AI. Unlike basic automation requiring constant human oversight, we’re engineering intelligent AI “workers” capable of serving as frontline agents, quality assurance analysts, and managerial roles, all while optimizing customer interactions continuously.We are rapidly expanding and seeking driven builders who thrive on solving complex technical challenges, act decisively, and wish to make a tangible impact in one of the fastest-growing voice AI startups.Join us in shaping the future!Recognized as a top 50 AI application in the a16z list: https://tinyurl.com/5853dt2xRanked #4 in Brex's Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025Featured among the top startups on: https://leanaileaderboard.com/

Join the Revolution at Retell AIRetell AI is pioneering the future of call centers through innovative voice AI, driven by first principles thinking.In just 18 months since our inception, we have empowered thousands of businesses with our AI voice agents, transforming how sales, support, and logistics calls are managed—previously requiring extensive human teams. Supported by prestigious investors such as Y Combinator and Alt Capital, we've rapidly scaled from $5M ARR to an impressive $36M ARR with a compact yet dynamic team of 20.Our ambition for 2026 is to create a revolutionary customer experience platform, where entire contact centers are powered by AI. Moving beyond basic automation, we aim to develop intelligent AI “workers” that serve as frontline agents, QA analysts, and managers, continuously enhancing customer interactions without the need for constant human oversight.As we expand, we are seeking passionate engineers who are eager to solve challenging technical problems, act swiftly, and make a significant impact in one of the fastest-growing voice AI startups. Let’s shape the future together.

Join Our Innovative Team at Retell AIRetell AI is at the forefront of revolutionizing the call center industry through advanced voice AI technology. In just 18 months since our inception, we have empowered thousands of businesses to optimize their sales, support, and logistics calls, which previously relied on large teams of human agents. Supported by prominent investors including Y Combinator and Alt Capital, we've achieved remarkable growth, scaling from $5 million to $36 million in annual recurring revenue (ARR) while expanding our talented team to 20 members.Our ambitious vision for 2026 is to develop a state-of-the-art customer experience platform, transforming entire contact centers with AI. Unlike traditional automation that requires ongoing human oversight, we are building intelligent AI "workers" capable of functioning as frontline agents, quality assurance analysts, and managers, constantly enhancing customer interactions.If you are a passionate innovator eager to solve complex technical challenges and make a tangible impact at one of the fastest-growing voice AI startups, we invite you to join us in shaping the future.Ranked among the top 50 AI applications by a16z: a16z List4th on Brex's Fast-Growing Software Vendors of 2025: Brex BenchmarkFeatured as a leading startup on: Leanaileaderboard

ABOUT RETELL AIRetell AI is at the forefront of revolutionizing call centers with innovative voice AI technology, utilizing first principles to redefine customer interactions.In just 18 months since our inception, thousands of companies have adopted Retell's AI voice agents to manage sales, support, and logistics calls that previously required extensive human teams. Supported by prestigious investors such as Y Combinator and Alt Capital, we have rapidly scaled to $36M ARR with a lean team of 20, up from $5M at the start of 2025.Our vision for 2026 is to create a modern customer experience (CX) platform where entire contact centers are powered by AI, moving beyond basic automation that relies on constant human intervention to intelligent AI “workers” that operate as frontline agents, quality assurance analysts, and managers, continuously executing, monitoring, and enhancing customer interactions.As we grow, we seek passionate builders eager to tackle challenging technical problems, accelerate progress, and make a genuine impact within one of the fastest-growing voice AI startups.Join us in shaping the future.Ranked among the top 50 AI applications in a16z's list: https://tinyurl.com/5853dt2x#4 on Brex's Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025Also recognized as a top-ranking startup on: https://leanaileaderboard.com/ABOUT THE ROLEAs a Senior Software Engineer - Support Automations at Retell, you will take charge of the technical support for our advanced, agentic voice AI platform. This hands-on leadership role involves personally troubleshooting complex customer issues, developing AI agents and automations, and guiding a growing team of support engineers.You will work at the intersection of engineering, customer relations, and product development, ensuring exceptional reliability, swift resolutions, and scalable support as Retell expands.This position is perfect for someone who thrives on solving intricate technical challenges in high-pressure environments, engages directly with customers, and enjoys building systems and teams from the ground up.

Join Retell AIAt Retell AI, we leverage first principles to revolutionize the call center experience through innovative voice AI technology.In just 18 months since our launch, our AI voice agents have been adopted by thousands of companies to manage sales, support, and logistics calls, significantly reducing the need for large teams of human agents. Supported by Y Combinator, Alt Capital, and other notable investors, we've achieved impressive growth, scaling from $5M to $36M ARR with a dedicated team of 20.Looking ahead to 2026, we aim to create a comprehensive AI-powered Customer Experience (CX) platform that transforms entire contact centers. Instead of simple automation requiring ongoing human oversight, we are developing intelligent AI "workers" that serve as frontline agents, QA analysts, and managers — perpetually executing, monitoring, and enhancing customer interactions.We're experiencing rapid growth and are on the lookout for passionate innovators eager to tackle complex technical challenges, accelerate progress, and make a significant impact at one of the leading voice AI startups.Let’s build the future together.Ranked in the top 50 AI applications by a16z: https://tinyurl.com/5853dt2x#4 on Brex's Fast-Growing Software Vendors list for 2025: https://www.brex.com/journal/brex-benchmark-december-2025One of the top startups on: https://leanaileaderboard.com/

About Retell AIRetell AI is pioneering the future of customer service by leveraging first principles to transform the call center experience through advanced voice AI technology.In just 18 months since our inception, our innovative AI voice agents have been utilized by thousands of companies to efficiently manage sales, support, and logistics calls, significantly reducing the need for large teams of human agents. With the backing of esteemed investors such as Y Combinator and Alt Capital, we have achieved an impressive $36 million ARR, growing from $5 million at the beginning of 2025 with a dedicated team of 20 professionals.Our ambitious vision for 2026 is to develop a state-of-the-art CX platform powered entirely by AI. We aim to create intelligent AI 'workers' that will function as frontline agents, QA analysts, and managers, capable of autonomously executing, monitoring, and enhancing customer interactions.We are rapidly expanding and seeking passionate innovators eager to solve challenging technical problems, work swiftly, and make a tangible impact at one of the fastest-growing voice AI startups. Join us in shaping the future.Recognized as a top 50 AI app in a16z's list: https://tinyurl.com/5853dt2xRanked #4 on Brex's Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025Listed among the top-ranking startups at: https://leanaileaderboard.com/About the RoleAs the Support Engineering Lead at Retell, you will be responsible for overseeing the technical support operations of our sophisticated voice AI platform. This hands-on leadership position involves directly troubleshooting complex customer challenges, developing AI agents and automations, and leading an expanding team of support engineers.You will work at the intersection of engineering, customer relations, and product development, ensuring unparalleled reliability, swift issue resolution, and scalable support systems as Retell continues its growth trajectory.This position is perfect for individuals who thrive on resolving intricate technical issues under pressure, engaging with clients directly, and constructing systems and teams from the ground up.

Join Us at Retell AIRetell AI is revolutionizing the call center industry by leveraging innovative voice AI technology based on first principles.In just 18 months since our inception, we have attracted thousands of companies that rely on Retell's AI voice agents to efficiently manage sales, support, and logistics calls, previously handled by large teams of human agents. Supported by renowned investors such as Y Combinator and Alt Capital, we have rapidly grown from $5M to $36M in Annual Recurring Revenue (ARR) with a dedicated team of 20.Looking ahead to 2026, our ambition is to establish a state-of-the-art customer experience platform entirely powered by AI. We aim to create intelligent AI “workers” capable of serving as frontline agents, quality assurance analysts, and managers, continuously optimizing customer interactions without the need for constant human oversight.We are on an exciting growth trajectory and are seeking driven individuals who are eager to solve complex technical challenges, accelerate progress, and make a significant impact at one of the fastest-growing voice AI startups.Let’s innovate the future together!Ranked as a top 50 AI app by a16z: https://tinyurl.com/5853dt2x#4 on Brex's Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025One of the top startups on: https://leanaileaderboard.com/

About Retell AI Retell AI builds voice AI technology for call centers, helping thousands of companies handle sales, support, and logistics calls with AI voice agents. Since launching 18 months ago, the company has grown annual recurring revenue from $5M to $50M, backed by investors including Y Combinator and Alt Capital. Our Mission By 2026, Retell AI aims to deliver a customer experience platform powered entirely by AI. The vision goes beyond basic automation: intelligent agents will take on roles as frontline workers, quality assurance analysts, and managers, improving customer interactions while reducing the need for ongoing human involvement. Recognition Ranked among the top 50 AI applications by a16z (a16z List) #4 on Brex's Fast-Growing Software Vendors of 2025 (Brex Benchmark) High placement on the Leana AI Leaderboard Working at Retell AI The team is expanding quickly and welcomes those who want to solve tough problems and help shape the future of voice AI. Retell AI is based in the San Francisco Bay Area and continues to grow as one of the industry's fastest-moving startups.

Role overview retell-ai seeks a Senior Software Engineer in the San Francisco Bay Area to focus on Go-To-Market (GTM) projects. This engineer will help shape how new products are created and introduced to customers, directly influencing the company’s approach to launching and scaling offerings. What you will do Collaborate with teams across the organization to translate business needs into software that advances GTM objectives. Develop and improve products to ensure they fit seamlessly into the market. Uphold high standards for code quality and system performance as products grow and change. Collaboration This position works closely with product, business, and engineering partners to deliver solutions that address both technical and market demands.

Join Retell AI as a Senior Full Stack Software EngineerAt Retell AI, we are revolutionizing the call center industry with innovative voice AI technology. Our cutting-edge solutions are designed to improve communication efficiency, allowing businesses to automate sales, support, and logistics calls that once required large teams of human agents. In just 18 months, we have experienced remarkable growth, achieving $36M in annual recurring revenue with a dedicated team of 20, up from $5M at the beginning of 2025.Our goal for 2026 is to create a modern customer experience platform powered entirely by AI. We are not just automating but building intelligent AI agents that can perform the roles of frontline agents, quality assurance analysts, and managers, continuously enhancing customer interactions.We are rapidly expanding and seeking talented individuals who are ready to solve challenging technical problems, work at a fast pace, and make a significant impact in one of the fastest-growing voice AI startups.Let’s shape the future of communication together!

ABOUT RETELL AIRetell AI is revolutionizing the call center landscape with cutting-edge voice AI technology founded on first principles.In just 18 months since our inception, thousands of companies trust Retell’s AI voice agents to manage sales, support, and logistics calls that traditionally required extensive teams of human agents. Supported by prestigious investors such as Y Combinator and Alt Capital, we have rapidly scaled to $36M ARR with a dedicated team of 20, up from $5M at the start of 2025.Our vision for 2026 is to establish a modern customer experience platform that empowers entire contact centers with AI. Rather than relying on basic automation that requires constant human oversight, we are developing intelligent AI “workers” that serve as frontline agents, quality assurance analysts, and managers — continuously executing, monitoring, and enhancing customer interactions.We are in a phase of rapid growth and are seeking ambitious innovators eager to solve complex technical challenges, move at a fast pace, and make a tangible impact at one of the fastest-growing voice AI startups.Join us in building the future together.Recognized as a top 50 AI application on a16z's list: https://tinyurl.com/5853dt2xRanked #4 on Brex's Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025Also listed among the top startups on: https://leanaileaderboard.com/

ABOUT RETELL AIRetell AI is pioneering the transformation of traditional call centers through innovative voice AI technology.In just 18 months since our inception, thousands of businesses leverage Retell's AI voice agents to efficiently manage sales, support, and logistics calls that previously required extensive human teams. Supported by Y Combinator, Alt Capital, and other esteemed investors, we've experienced rapid growth, increasing our annual recurring revenue (ARR) from $5M to $36M with a dedicated team of 20.Looking ahead to 2026, we aim to develop a comprehensive customer experience (CX) platform, fully powered by AI. Our goal is to go beyond basic automation, creating intelligent AI “workers” that serve as frontline agents, quality assurance analysts, and managers—constantly optimizing and enhancing customer interactions.As we expand, we are seeking enthusiastic builders ready to engage with complex technical challenges, accelerate innovation, and make a significant impact at one of the fastest-growing voice AI startups.Join us in shaping the future!Featured as a top 50 AI app on a16z's list: https://tinyurl.com/5853dt2xRanked #4 on Brex's Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025One of the top startups on: https://leanaileaderboard.com/

Join Our Team at Retell AIAt Retell AI, we are pioneering the future of call centers with innovative voice AI technology. In just 18 months, our cutting-edge AI voice agents have transformed how thousands of companies handle their sales, support, and logistics calls, reducing reliance on extensive human teams. Supported by renowned investors such as Y Combinator and Alt Capital, we have achieved remarkable growth, scaling from $5 million to $36 million in annual recurring revenue (ARR) with a dedicated team of 20.Our ambitious vision for 2026 is to develop a comprehensive customer experience platform powered entirely by AI. We are redefining automation by building intelligent AI agents capable of functioning as frontline representatives, quality assurance analysts, and managers, ensuring continuous improvement in customer interactions.As we expand, we seek passionate innovators eager to tackle challenging technical problems and make a significant impact at one of the fastest-growing startups in voice AI. Together, let’s shape the future.Recognized as a top 50 AI application in the a16z list: https://tinyurl.com/5853dt2xRanked #4 on Brex's Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025One of the top startups on: https://leanaileaderboard.com/About the RoleWe are looking for a Senior Product Designer to craft exceptional products at Retell. You will design the infrastructure and tools that enable real-time AI voice agents used by dynamic companies. The quality of design is paramount as every interaction occurs in real time, with actual users under pressure.In this role, you will take ownership of end-to-end product design across essential user workflows. Collaborating closely with founders, engineers, and customers, you will shape features from the ground up, rather than merely refining existing user interfaces. This position offers substantial ownership and influence over product direction, user experience quality, and design standards.

At Mercury, every new customer who applies for a bank account represents a new star igniting in a vast universe of possibilities. Initially, it may seem like a mere spark, but a closer examination reveals an intricate constellation of identity verification, ownership checks, sanctions screening, and fraud signals—all interconnected by invisible forces. The Risk Engineering team acts as the guiding navigation system for this expansive universe. Our mission is to safely guide thousands of ambitious individuals through Mercury’s orbit each day—each with a unique trajectory, risk profile, and narrative. We operate at escape velocity: moving swiftly, making confident decisions, and safeguarding the system without hindering the builders who depend on us. When we excel, founders can open bank accounts in delightful minutes rather than days, without needing to worry about the underlying complexities. We are on the brink of a new era. We are developing intelligent AI systems that do not merely assess risk but can reason about it—systems capable of investigating, deciding, escalating, and learning. These agents will enhance our KYC Refresh, EDD, ODD, and compliance workflows, propelling our operations to unprecedented levels of efficiency and scale. Our goal: to reduce manual labor, detect risks earlier, make sharper decisions, and create experiences that are almost magical in their simplicity. Now, we invite you to join us. We are seeking a Senior Software Engineer who is inspired by the prospect of bringing intelligent automation to life within real production systems. We need someone eager to design and implement AI-driven workflows that can think in steps, adapt to new information, and orchestrate complex decisions across people, models, and services. If you view compliance not as red tape but as a fascinating systems challenge at planetary scale, we want you. If you are excited about building impactful AI that safeguards millions of dollars, opens doors for founders globally, and helps shape the future of banking, we would love to explore this journey together. *Mercury is a fintech company, not an FDIC-insured bank. Banking services provided through Choice Financial Group and Column N.A., Members FDIC.

Responsibilities:Develop Our Product. Take ownership of software features that enhance our AI platform, empowering private market investors to analyze deals swiftly and accurately. This role requires you to actively engage in coding and delivering essential platform components from the ground up.Ensure Quality and Excellence. Establish and maintain coding standards, architectural guidelines, and review procedures; mentor fellow engineers. Co-cultivate a culture centered on practical, reliable, and test-driven development that swiftly meets business requirements.Scale for Growth. Assist in monitoring and scaling the architecture of our platform and its infrastructure.Collaborate Across Functions. Engage closely with product, security, and go-to-market teams to translate our strategic roadmap into actionable features and deliverables.

fractional-ai is looking for a Senior or Staff Software Engineer to join the San Francisco office. This position centers on building advanced AI solutions with a team that values both technical depth and collaboration. Role overview This role focuses on designing and developing AI-driven systems. The work involves solving technical challenges and contributing to projects that push the boundaries of what AI can achieve. Collaboration with other engineers and stakeholders is a key part of daily responsibilities. Who will thrive Experienced engineers with a strong background in software development Those who enjoy working on complex technical problems Individuals who value teamwork and open communication Location This position is based in the San Francisco office.

Are you ready to push the boundaries of your capabilities?At Coinbase, we are on a mission to enhance economic freedom globally. This ambitious goal challenges us to excel every day as we construct the future of the on-chain platform and the global financial system.We are looking for a unique individual who is not only passionate about our mission but also believes in the transformative potential of cryptocurrency and blockchain technology in modernizing the financial landscape. We seek someone eager to make a significant impact, thrives under pressure, collaborates with exceptional colleagues, and actively seeks constructive feedback to foster personal growth. We want someone who approaches the company's toughest challenges head-on.Our work culture is intense and may not be for everyone. However, if you aspire to shape the future alongside high-performing peers who expect the same from you, there is no better place to be.While many positions at Coinbase embrace a remote-first approach, we are not entirely remote. In-person participation is required periodically throughout the year. We organize team and company-wide retreats multiple times annually to enhance collaboration, connection, and alignment, and attendance is both expected and supported.As we strive to fulfill our mission, we are evolving into an "AI-first" organization, fundamentally rethinking the operations of a global financial institution. Artificial Intelligence is central to this strategy, enhancing our core processes while human experts provide high-level judgment as the system's "function calls".The RoleWe are in search of a visionary Principal Software Engineer with a focus on AI to serve as the technical guiding force for our AI Automation initiatives. You will be responsible for developing Agentic AI systems that drive multiple organization-wide projects, including their foundational elements, orchestration layers, and the tools necessary for every Coinbase team to automate their workflows. Reporting to the VP of Engineering, you will operate with a high degree of autonomy to define the essence of a fully AI-driven enterprise from the ground up.What You’ll DoArchitect Agentic Systems: Innovate and construct sophisticated multi-agent architectures that transition from simple interactions to autonomous execution and intricate reasoning.Tackle the "Hard Problems" of AI: Establish and implement reliable evaluation frameworks, eliminate hallucinations through rigorous data grounding, and build comprehensive solutions.

Are you ready to elevate your skills and push your boundaries?At Coinbase, our mission is to enhance economic freedom globally. This ambitious goal calls for our best efforts as we work to build the next-generation onchain platform that will define the future of the global financial system.We are looking for an exceptional candidate who shares our passion and believes in the transformative power of cryptocurrency and blockchain technology. We want individuals who are eager to make a significant impact, thrive under pressure, and actively seek constructive feedback to continuously improve. Join us in tackling the toughest challenges and shaping the future.Our work culture is intense and challenging, but for those who aspire to innovate alongside top-tier talent, it’s an unparalleled opportunity.While many roles at Coinbase embrace a remote-first approach, we value in-person collaboration. Team and company-wide offsites are organized multiple times a year to strengthen connections and alignment; attendance is both expected and fully supported.The Core Automation Team is a dynamic and innovative group focused on developing AI infrastructure and automation solutions that enhance productivity and create meaningful impacts for our customers. Our goal is to streamline operations for customer support and compliance teams, ensuring outstanding customer experiences. As a Software Engineer on our team, you will be pivotal in this transformation, utilizing cutting-edge AI models, frameworks, and tools, alongside a wealth of data sources, including blockchain data. Your contributions will help dismantle barriers to cryptocurrency adoption and define the future of AI-driven customer interactions.

Join Us in Combating the Escalating Wildfire Crisis with Cutting-Edge AI and IoT SolutionsAbout UsThe Challenge: In the face of climate change, wildfires are becoming more frequent and severe. Traditional methods of fire detection, reliant on bystanders and emergency calls, lead to critical delays in response times. Fire authorities require innovative solutions for faster detection, verification, and response to avert catastrophic fire outbreaks.Who We Are: Pano AI is a dynamic growth-stage startup based in San Francisco, comprising over 150 passionate professionals. We stand at the forefront of wildfire detection and intelligence, equipping fire services with timely information and advanced technology to enhance their response capabilities. Our platform integrates cutting-edge hardware, software, and AI, utilizing ultra-high-definition 360-degree cameras positioned strategically to provide real-time threat assessments. Our technology empowers fire professionals with actionable insights, enabling them to prevent minor flare-ups from escalating into significant disasters.Recognized by TIME as one of the 100 Most Influential Companies of 2025, and featured in MIT Technology Review's top 15 climate tech companies to watch, Pano AI is paving the way for innovative solutions in fire response. Our contributions have been recognized in major publications such as the Wall Street Journal and Bloomberg.