Senior Backend Software Engineer at Retell AI | San Francisco Bay Area

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/

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

Join Retell AI as a Senior Machine Learning EngineerRetell AI is at the forefront of revolutionizing the call center industry using groundbreaking voice AI technology. Within just 18 months of our inception, we have empowered thousands of businesses with our AI voice agents capable of managing sales, support, and logistics calls that traditionally required extensive human teams.Supported by renowned investors, including Y Combinator and Alt Capital, our journey has seen us scale from $5M to an impressive $36M ARR with a dedicated team of 20. Our ambition for 2026 is to develop a state-of-the-art customer experience platform, transforming entire contact centers with AI. We are building intelligent AI “workers” that will serve as frontline agents, quality assurance analysts, and managers—constantly executing, monitoring, and enhancing customer interactions.We are rapidly expanding and seeking passionate innovators eager to solve complex technical challenges and make a tangible impact in one of the fastest-growing voice AI startups. Together, let's shape the future of customer interactions.

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.

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 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/

Backend Software Engineer – AI Applications San Francisco Bay Area | Hybrid (3 days onsite, 2 remote)About TrueMeterAt TrueMeter, we are revolutionizing the way businesses manage their energy costs. The U.S. power grid was not designed for the AI era, and we are here to change that. With the rising demand for data centers and the lagging adoption of renewable energy, many businesses are facing increasing utility bills. Our solution? The AI Energy Agent—a system that simplifies and reduces energy costs by consolidating multiple utility bills into a single, affordable subscription. Since our MVP launch in May 2024, we have successfully onboarded millions in energy spending from notable brands. As a seed-stage startup backed by prominent Silicon Valley investors, we are poised for rapid growth.If you are passionate about developing AI-driven systems that can make a significant impact on the planet, we want to hear from you!The RoleWe are seeking a Backend Software Engineer (AI Applications) who thrives in fast-paced, early-stage environments. In this role, you will transform ideas and prototypes into functional systems in a matter of days.You will be responsible for creating the backend infrastructure that powers our AI Energy Agent, including LLM-driven systems that analyze, structure, and interpret energy data. This includes integrating with multiple utility APIs, managing data pipelines, and developing services that ensure our AI solutions are effective and reliable.You will collaborate closely with the co-founder/CTO and a talented team of engineers, designing scalable backend systems that can grow from 10 customers to 10,000, all while taking ownership of your work and delivering with pride.What You Will CreateAI-Driven Backends: Develop production systems that connect LLMs and coding agents to our data and product APIs.Service Architecture: Design and implement fast, secure microservices using Python (and optionally TypeScript).Data Integration: Build reliable connectors to energy company portals and public data sources.Infrastructure for Intelligence: Help architect the backend infrastructure that enables AI agents to read, reason, and act autonomously across our data stack.Performance & Scalability: Own systems that are designed to operate 24/7 with low latency and high reliability.

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.

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!

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 Our MissionThe trucking and logistics sector is essential to our economy, yet its payment infrastructure is outdated and inefficient. At AtoB, we are on a mission to revolutionize payment systems for this industry. We've identified the challenges faced by hardworking professionals in trucking — from outdated tools to hidden fees, and we are committed to delivering solutions that prioritize their needs.About AtoBOur goal is to create a seamless payment experience akin to Stripe, tailor-made for the transportation industry. We understand the critical role of timely capital movement in supply chains and strive to ensure it happens smoothly and fairly. Every product we develop enhances user experience and works intelligently within the unique constraints our customers face daily, whether they are fleet managers or drivers.Our ExpertiseOur founding team boasts extensive experience in the tech and payments landscape, with backgrounds from industry leaders like Cruise Automation, Uber, Google, Meta, and Stripe. We've attracted over $125 million in funding from prominent investors, including General Catalyst, Y Combinator, and major tech founders, positioning us as a leader in innovation within our sector.Recognized by Forbes as one of the Next Billion-Dollar Startups, we are also proud to join the World Economic Forum as a Global Innovator.

About UsEma is at the forefront of developing next-generation AI technologies designed to empower every employee within the enterprise landscape, enhancing their creativity and productivity. Our cutting-edge proprietary technology enables businesses to automate repetitive tasks efficiently, introducing Ema as the Universal AI employee. Founded by former executives from Google, Coinbase, and Okta, along with seasoned entrepreneurs, we are financially backed by some of the world's leading investors and angels. Ema operates from Silicon Valley and Bangalore, and this position offers a hybrid work model, requiring in-office attendance three days a week.Your RoleWe are on the lookout for a passionate Software Engineer to join our dynamic Ema team. If you have a knack for designing and building maintainable software applications and enjoy tackling complex problems, we want to hear from you. We value creativity and are excited to welcome someone who thrives in a mission-driven, fast-paced startup environment.Key ResponsibilitiesDesign, develop, and maintain enterprise software applications, focusing on API, data, application, and service development.Create clean, efficient, and maintainable code while implementing a test-driven development approach.Build scalable and robust backend systems utilizing programming languages such as Go and Python.Develop and manage APIs using REST and gRPC protocols.Create and maintain scalable data schemas in databases like PostgreSQL and Clickhouse.Contribute to front-end interface development using HTML, CSS, and JavaScript frameworks like React or Angular.Ensure application security by adhering to industry best practices.Continuously enhance software development processes and methodologies.QualificationsBachelor's degree in Computer Science or a related field.A minimum of 4 years of experience in software development.Strong understanding of algorithms, data structures, and object-oriented programming.Proficiency in backend development with languages such as Python and Go.Familiarity with database technologies including PostgreSQL, Elastic, and Redis.Experience in designing and developing API platforms and integration systems.Knowledge of cloud technologies such as GCP, AWS, and Azure.

Who are we?At Ema, we are pioneering the future of AI technology, empowering employees across enterprises to unleash their creativity and productivity. Our innovative platform enables businesses to delegate repetitive tasks to Ema, the Universal AI employee. Founded by former leaders from Google, Coinbase, and Okta, we are backed by world-class investors and angels. Our headquarters are located in Silicon Valley and Bangalore, and this position offers a hybrid work model with three days in the office each week.Who are you?We are looking for a dedicated Backend Software Engineer to join our dynamic team. You possess a passion for creating maintainable software solutions and are an innovative problem solver who can navigate through complexities. Most importantly, you are eager to contribute to a mission-driven, fast-paced startup that aims to make a significant impact.Your Responsibilities:Design, develop, and maintain enterprise software applications, focusing on APIs, data processing, and service development.Write clean, efficient, and maintainable code using a test-driven development approach.Construct scalable and reliable backend systems utilizing programming languages such as Go and Python.Create and manage APIs using REST and gRPC protocols.Develop and uphold scalable and extensible data schemas with technologies like PostgreSQL and Clickhouse.Contribute to frontend interfaces using HTML, CSS, and JavaScript frameworks like React or Angular.Ensure security and adherence to industry best practices in all applications.Continuously enhance software development processes and methodologies.Qualifications:Bachelor's degree in Computer Science or a related field.Minimum of 4 years of relevant experience in software development.Strong understanding of algorithms, data structures, and object-oriented programming principles.Proficient in backend development with experience in languages such as Python and Go.Familiarity with database technologies, including PostgreSQL, Elastic, and Redis.Experience designing and implementing API platforms and integration systems.Knowledge of cloud technologies such as GCP, AWS, and Azure.

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.

About HexusAt Hexus, we are dedicated to unlocking the hidden potential of AI and personalization for businesses. Our passion lies in revolutionizing product-led growth, transforming how companies connect with their customers, thereby enhancing product adoption and ensuring long-term success. With a robust suite of AI-driven tools, Hexus enables businesses to optimize their PLG strategies across Sales, Marketing, and Customer Experience.Supported by leading investors, industry experts, and renowned angel investors, our team is spearheaded by former FAANG founders with extensive experience in SaaS, ML, and UX. Join us in our mission to redefine customer experiences through AI and personalization.Your RoleAs a dynamic, design-driven startup, we are seeking a talented Senior Product Engineer to join our early-stage team. You will be instrumental in actualizing our product vision by creating clean, intuitive UI and UX, developing robust editing tools, and ensuring top-notch performance. We seek an individual who raises the bar for what’s achievable online and is passionate about crafting exceptional responsive, interactive, and enjoyable user experiences.In this role, you will:Collaborate closely with the founding team to design engaging user experiences.Execute critical projects that empower our customers daily.Rapidly prototype and iterate on new features and functionalities, driving ongoing innovation.Architect efficient and reusable frontend systems that support complex web applications.Contribute to shaping the direction of our design-led product.Qualifications5+ years of experience in frontend development.Proficiency in front-end development using TypeScript, React, NextJS, and Node.js.Strong skills in design and styling with frameworks like Tailwind or Material Design.Comprehensive understanding of the entire web stack, including protocols and web server optimization techniques.Familiarity with modern deep learning models (GPT, LLAMA, BERT, Whisper, Stable Diffusion, etc.).Capacity to grasp user challenges and convert them into features and products.A desire to thrive in a fast-paced, iterative startup environment.

Join Saris AI as a Staff Backend Software Engineer, where you will play a pivotal role in developing innovative solutions that harness the power of artificial intelligence. In this dynamic position, you will collaborate with cross-functional teams, design scalable systems, and contribute to the overall architecture of our backend solutions.

About TaktOur Vision: A world where factories are intelligent.At Takt, we are revolutionizing manufacturing by developing the cognitive capabilities of factories.Despite a decade of digitization efforts involving sensors, software, and dashboards, many factories remain unintelligent. Data is often scattered across various disconnected systems, trapped in reports, and reliant on the unwritten know-how of individuals.The challenge lies not in data collection, but in transforming this data into actionable institutional intelligence.Takt is advancing the manufacturing landscape by seamlessly integrating AI agents with deep operational context throughout the entire production stack. Our systems analyze what is happening, why it is occurring, and what actions to take, acting as a continuous strategic advisor for factory leadership across sales, operations, supply chain, and finance.This is not merely another chatbot or analytics tool; we are at the forefront of AI reasoning and decision-making in critical, real-world environments. Just as Tesla redefined automobiles as software-centric systems, Takt is transforming manufacturing into a software-driven industry.FundingTakt is proudly backed by Pear VC (investors in Doordash and Gusto) and is a participant in the PearX accelerator program.Visit our website: www.taktconnect.comFoundersTakt was founded by Adhitya Raghavan (CEO) and Will Zunker (CTO). Adhitya's journey from a small village in South India to leading Takt is fueled by his personal experiences on factory floors. His path led him through prestigious institutions such as Princeton (Mechanical & Aerospace Engineering), Harvard (MBA, Baker Scholar), and Bain, and now he is committed to addressing the $8 trillion waste problem in the manufacturing sector.

About UsEma is at the forefront of developing cutting-edge AI technology designed to enhance creativity and productivity for every employee within the enterprise. Our innovative solutions enable businesses to automate repetitive tasks through Ema, the Universal AI employee. Founded by industry veterans from Google, Coinbase, and Okta, we are backed by some of the world's leading investors and angels. With headquarters in Silicon Valley and Bangalore, we offer a dynamic hybrid work environment, with employees expected to work from the office three days a week.Your RoleWe are on the lookout for a skilled Backend Software Engineering Lead to join our vibrant team. In this role, you will spearhead the design, development, and maintenance of our enterprise software applications. Collaborating with a multidisciplinary team of product managers, designers, and developers, you will deliver top-notch software solutions tailored to meet our enterprise clients' needs. The ideal candidate will possess extensive experience across the technology stack and a strong grasp of web frameworks, APIs, databases, and various back-end programming languages. Above all, you should be passionate about contributing to a rapidly growing startup with a mission to make a significant impact.Key ResponsibilitiesDevelop and maintain enterprise software applications, focusing on API, data, application, and service development.Write clean, efficient, and maintainable code through a test-driven development process.Construct scalable and reliable back-end systems using programming languages such as Go and Python.Design and maintain APIs utilizing REST or GraphQL standards.Integrate various enterprise applications and services using scalable frameworks like FastAPI.Create and manage data schemas with PostgreSQL, Redshift, etc.Contribute to front-end interfaces employing HTML, CSS, and JavaScript frameworks like React or Angular.Ensure application security and adherence to industry best practices.Continuously enhance software development processes and methodologies.

Dapster is actively seeking a Lead Hardware Engineer to become a pivotal part of our dynamic team. As a rapidly growing startup, this position offers the unique opportunity to influence our foundational technologies and products.About Dapster: We are dedicated to revolutionizing the market with AI-driven robotic picking solutions. Recently, we secured a significant pilot project with a top retailer, providing us with dilution-free funding to further develop our core technology.If you're eager to engage in innovative work alongside a talented and humble team, and want to share in the rewards of joining us at such an early stage, we’d love to hear from you!