Content Strategist at HappyRobot | San Francisco

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 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About UsAt Amari AI, we are transforming the logistics industry by replacing outdated manual workflows with intelligent AI agents. Our cutting-edge technology collaborates with human operators, automating complex, document-heavy processes to enable faster, more accurate shipment processing.Having surpassed the initial development phase, we have successfully achieved product-market fit and are experiencing exceptional growth, with over 100% month-over-month revenue increase. With $5 million raised from notable investors including First Round Capital and Pear VC, we are expanding our platform's capabilities. Our highly skilled team is composed of experts from leading tech companies such as Google, LinkedIn, and Salesforce, as well as prestigious academic institutions and AI research facilities.The RoleIn the capacity of Senior Backend Engineer at Amari AI, you will play a pivotal role in shaping the core data infrastructure that drives our AI-powered logistics platform. This position offers substantial ownership and autonomy, allowing you to design and scale systems responsible for ingesting, processing, and delivering real-time logistics data across various AI components, including pipelines, queues, databases, and search layers. Your technical leadership will significantly influence product reliability and performance from the outset.What You’ll DoDesign and scale distributed backend systems - including queue pipelines, service boundary definitions, and robust failure management strategies such as retry mechanisms, circuit breakers, and graceful degradation.Manage database design and reliability - focusing on schema design, indexing strategies, and query optimization tailored to specific use cases, along with data pipelines that maintain synchronization across systems at scale.Develop AI-driven search infrastructure for real-time logistics lookups and enhanced AI features.Provide technical leadership in a dynamic startup environment - establishing engineering standards, collaborating closely with the founders on strategic roadmaps, and mentoring future backend engineers.Who We're Looking For5–8 years of professional experience in backend software engineering, preferably in high-growth startups or large-scale production environments.Proven track record of end-to-end ownership of backend systems in fast-paced, ambiguous settings.Demonstrated capability in making informed architectural decisions under time constraints, with flexibility to adapt as requirements evolve.

About HappyRobotHappyRobot is revolutionizing the real economy with our AI-native operating system designed to bridge the gap between intelligence and action. By integrating real-time insights with specialized AI capabilities, we empower enterprises to manage complex operations autonomously.Our AI OS continuously accumulates knowledge, optimizes various processes, and adapts over time. We are initially focusing on supply chain and large-scale industrial operations, where speed, resilience, and ongoing improvement are paramount—allowing human resources to concentrate on strategic and creative high-value tasks.Discover more about our vision in our Manifesto. So far, HappyRobot has successfully raised $62M in funding, including a recent $44M in Series B financing as of September 2025. Our esteemed investors include Y Combinator (YC), Andreessen Horowitz (a16z), and Base10, who share our mission to transform enterprise operations. We are leveraging this investment to build a top-tier team of individuals with unwavering motivation, exceptional problem-solving capabilities, and a drive to exceed limits in a dynamic working environment. If this resonates with you, we want you at HappyRobot.About The RoleAt HappyRobot, our Senior Backend Software Engineers are entrusted with significant components of our product and infrastructure, overseeing projects from inception to deployment. We are seeking passionate builders who thrive in uncertain environments, value craftsmanship, and desire genuine ownership of their creations.

About HappyRobotHappyRobot serves as the essential infrastructure for enterprises aiming to construct and manage AI-driven workforces. Our AI agents are not just communicators; they are capable of making autonomous decisions, taking actions, and managing operations across various platforms including voice, email, and enterprise systems. Founded in Y Combinator (S23) and supported by renowned investors such as a16z and Base10, we have successfully raised over $60 million and are dedicated to empowering vital operations for global enterprises.Our platform has been rigorously tested in challenging environments, where the implications of AI are significant. We initially focused on logistics, developing our own voice stack, models, and orchestration layer entirely from scratch, and are now working to extend this infrastructure to every enterprise that plays a role in the real economy. Discover more about our vision in our manifesto.

Who We AreLightning AI, the driving force behind PyTorch Lightning, was established in 2019. We have developed a comprehensive platform that streamlines the process of creating, training, and deploying AI systems, transforming innovative ideas from research to production with greater efficiency.Following our merger with Voltage Park, a leading neocloud and AI Factory, we are proud to combine cutting-edge developer-focused software with cost-effective, large-scale computational resources. Our platform provides teams with essential tools for experimentation, training, and production inference, all while ensuring security, observability, and control.Our clients range from independent researchers to startups and large enterprises. Lightning AI has a global footprint, with offices in New York City, San Francisco, Seattle, and London, and is supported by prominent investors including Coatue, Index Ventures, Bain Capital Ventures, and Firstminute.Our ValuesMove Fast: We prioritize speed and precision, breaking down complex challenges into manageable steps.Focus: We tackle one goal at a time, working collaboratively to deliver features with accuracy.Balance: We believe sustained performance is rooted in rest and recovery, promoting a healthy work-life balance to optimize your performance.Craftsmanship: We value excellence and attention to detail, taking pride in honing our skills.Minimal: We embrace simplicity as a driver of innovation, eliminating unnecessary complexity through disciplined focus on what truly matters.What We're Looking ForWe are seeking a talented Backend Engineer to contribute to the development and scaling of the Lightning AI platform, encompassing frontend, CLI, API, billing, security, and integrations.The ideal candidate will take ownership of significant features and lead development efforts from conception to launch while collaborating with a highly skilled team of engineers, product managers, and designers. You will have the opportunity to advance groundbreaking technology that will reshape the machine-learning ecosystem!You will join the Blue Squad and report to our Director of Engineering. This is a hybrid position based in our Bay Area office, requiring in-office attendance two days per week.

About HappyRobotHappyRobot serves as the foundational infrastructure enabling enterprises to develop and manage AI workforces. Our AI agents not only communicate effectively but also make autonomous decisions, take actions, and operate seamlessly across various platforms including voice, email, and enterprise systems. Originating from Y Combinator (S23) and supported by a16z and Base10 with an impressive $60M in funding, we are integral to the operations of critical global enterprises.Our platform is rigorously tested in demanding environments where the stakes are high. We began in the logistics sector, creating our unique voice stack, models, and orchestration layer from scratch, and we are now extending this robust infrastructure to every enterprise engaged in the real economy. Discover more about our vision in our manifesto.About the RoleWe are seeking a highly organized, proactive, and resourceful Executive Assistant to support our founders and ensure smooth operations. This role offers a unique opportunity to closely collaborate with leadership in a dynamic, fast-paced environment.What You’ll DoManage calendars, schedule meetings, and coordinate travel arrangements for the founders.Effectively prioritize and handle incoming requests to maximize their time.Prepare meeting agendas, take detailed notes, and follow up on action items.Serve as a primary point of contact between the founders and both internal and external stakeholders.Assist with special projects, research, and confidential tasks as needed.Must Have3-5+ years of experience supporting C-Suite Executives.Demonstrated ability in managing complex, high-volume calendars across multiple time zones.Exceptional organizational and detail-oriented skills, capable of handling multiple priorities effortlessly.Strong communication skills, with the ability to anticipate needs and ensure smooth operations.Discretion and professionalism in handling confidential matters.Proactive and resourceful, with a knack for identifying solutions before challenges arise.Why Join Us?Be part of a pioneering company at the forefront of AI workforce innovation.Collaborate with talented professionals in a vibrant and supportive work environment.

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.

About UsOur mission is to revolutionize language learning.Learning a new language can transform lives by providing access to diverse cultures, career opportunities, and communities. With two billion people globally striving to learn languages, the most effective method—one-on-one tutoring—remains difficult to access at scale and has not evolved significantly over the years. Speak is developing an AI-powered, human-like tutor that fits in your pocket, offering a conversation-first approach that allows learners to practice speaking, receive immediate feedback, and progress through thoughtfully designed lessons. This results in a comprehensive journey from novice to confident speaker across multiple languages.Since our launch in South Korea in 2019, Speak has emerged as the leading language learning app, now available to learners in various markets and over 15 languages. As one of the foremost AI companies globally, we have secured over $150 million in venture capital from notable investors such as OpenAI, Accel, Founders Fund, and Khosla Ventures, with a diverse team spread across San Francisco, Seoul, Tokyo, Taipei, and Ljubljana.About This RoleWe are seeking a Senior Backend Engineer, with full-stack capabilities, to help create innovative AI-driven product experiences. The ideal candidate should have experience collaborating closely with product, design, and machine learning teams, alongside a proven track record in developing polished consumer applications. This role is pivotal in shaping our latest products focused on programmatic, conversational language learning and will significantly impact the future direction of our company.Your ResponsibilitiesCrafting innovative AI-driven product experiences and user interfaces for the web.Full-stack engineering with a primary focus on designing scalable backend systems.Troubleshooting complex streaming challenges.Taking ownership of the complete development cycle of features from ideation to production.Writing code efficiently, shipping frequently, and making a substantial impact on our business by facilitating the scaling of our content.Your Profile5+ years of industry experience as a Backend Engineer, ideally within a fast-paced startup environment.Bonus: Experience on an app that has reached over 1 million users.Exceptional problem-solving and communication skills, along with the ability to work effectively in a collaborative environment.

Role OverviewLocated in the heart of San Francisco, CA, this position is integral to our headquarters and does not support full-time remote work.Compensation for this role ranges from $150,000 to $250,000 annually, depending on experience, along with equity and comprehensive benefits.About FurtherAIAt FurtherAI, we are pioneering advanced AI agents tailored for the insurance sector, a market primed for innovation worth trillions. Having successfully secured over $30 million from prestigious investors such as Andreessen Horowitz, Y Combinator, Nexus, South Park Commons, and Converge, we've experienced a remarkable tenfold revenue growth this year. Our clientele includes some of the most renowned names in insurance, including a top 5 global insurance company. Our team merges profound AI knowledge with extensive entrepreneurial experience.We are currently seeking an extraordinary Software Engineer to join our foundational team and help shape our product and organizational culture.Why Work With Us?Accelerated Growth: Experience rapid revenue growth post-product-market fit.Exceptional Team: Our founding group features talents from Apple AI Research, four ex-Y Combinator founders, and six successful entrepreneurs. Our engineering team boasts backgrounds from Apple, Microsoft, Google, and Amazon.Deep Technical Challenges: Collaborate with a staff research scientist and a team of seven engineers tackling advanced AI and scalable backend solutions.Significant Market Influence: Our work is transformative, reshaping the insurance industry's operational landscape.Entrepreneurial Spirit: Ideal for those looking to take ownership of critical product areas and possibly launch their own ventures in the future.Your ResponsibilitiesDevelop and enhance the core product, ensuring optimal performance, reliability, and ongoing improvements.Take charge of substantial elements of the backend architecture using Python.Work closely with founders to define and guide the technical roadmap.Embrace a culture of extreme ownership within a dynamic, high-performance environment.Engage in-person at our San Francisco office (5 days a week).

About HappyRobotHappyRobot is a pioneering AI-native operating system designed for the real economy. We bridge the gap between intelligence and action by integrating real-time insights, specialized AI operatives, and orchestrating intelligence. Our technology empowers enterprises to manage complex, mission-critical operations with genuine autonomy.Our AI OS continually enhances knowledge, optimizes processes, and adapts over time. We are focusing initially on supply chain and large-scale industrial operations, where resilience, speed, and ongoing improvement are crucial—allowing humans to concentrate on strategy, creativity, and other high-value activities.Discover more about our vision in our Manifesto. To date, HappyRobot has secured $62M in funding, including a recent $44M Series B round in September 2025. Our investors include Y Combinator (YC), Andreessen Horowitz (a16z), and Base10—partners who share our commitment to transforming enterprise operations. We are channeling this investment into building a world-class team—individuals with relentless drive, exceptional problem-solving abilities, and a passion for pushing boundaries in a dynamic, high-intensity setting. If this resonates with you, consider joining HappyRobot.About The RoleAt HappyRobot, Backend Software Engineers take ownership of critical components of our product and infrastructure from inception to deployment. We are seeking passionate builders who excel in uncertain environments, value craftsmanship, and desire true ownership of their creations.

Join our dynamic team at unify as a Senior Backend Software Engineer, where you will leverage your expertise to design and implement robust backend systems that enhance our product's performance and scalability. You will collaborate closely with cross-functional teams to develop innovative solutions that meet our customers' needs.

Join Our Innovative Team at ClericAt Cleric, we are on a mission to develop a cutting-edge autonomous AI agent designed to investigate and resolve production incidents efficiently. Our state-of-the-art agent utilizes large language models (LLMs) alongside advanced tools to comprehend complex systems, analyze problems, and implement corrective measures, even for unprecedented issues.Our technology is already making waves in high-scale companies across various sectors, including fintech, ride-sharing, and autonomous vehicles.About the RoleWe are seeking a talented Backend Software Engineer to join our dynamic team in scaling our autonomous agent technology. This position is perfect for engineers eager to develop, deploy, and enhance AI systems within real-world environments.You will collaborate closely with senior engineers on agent reasoning, integrations, and runtime systems, playing a pivotal role in delivering impactful customer-facing features.Your ResponsibilitiesEnhance capabilities of our autonomous agent and streamline tool execution workflowsDevelop and expand integrations with existing production systemsAssist in creating tools for agent evaluation and observabilityPartner with senior engineers to design, implement, and deliver new featuresGain insights into building reliable AI systems for production environmentsQualifications1–2 years of professional experience in software engineeringStrong understanding of software engineering principles and system designProficiency in Python (familiarity with other programming languages is a plus)A keen interest in AI, machine learning, and agentic systemsA passion for rapid learning and tackling real-world production challengesPreferred SkillsFamiliarity with AI/ML systems or LLM-based productsExperience with distributed systems or cloud infrastructureBackground in startup or fast-paced team settingsOur Work CultureSmall teams that create a significant impactEncouragement of radical candor in a supportive environmentEmphasis on in-person collaborationAn AI-first approach in all our endeavors

About braintrustBraintrust is at the forefront of AI observability, merging evaluation and observability into a seamless workflow. Our platform empowers developers to gain critical insights into AI behavior in production environments and provides tools for optimization.Renowned companies such as Notion, Stripe, Zapier, Vercel, and Ramp leverage Braintrust to assess models, test prompts, and identify regressions, transforming production data into enhanced AI performance with each update.About the RoleWe are seeking a passionate Backend Engineer to contribute to the foundational infrastructure of innovative AI development tools.Braintrust operates as a real-time, highly available data platform within both SaaS and self-hosted ecosystems. Your contributions will be pivotal in scaling our data ingestion pipelines, enhancing our open-source libraries, and ensuring optimal system performance and reliability. If you excel in a dynamic environment and relish tackling complex systems challenges with a product-oriented mindset, we would love to collaborate with you.Your ResponsibilitiesAs a Backend Engineer at Braintrust, you will play a key role in shaping the core platform that facilitates LLM-native development:Design and deploy features that provide users with profound insights into their LLM utilization and performance metrics.Integrate, proxy, cache, and aggregate data from leading model providers such as OpenAI, Anthropic, and Gemini, which our clients depend on.Create and refine robust, efficient open-source libraries for tracing and evaluating LLM calls within client applications. Explore our SDKsDevelop highly available real-time data pipelines to ingest, store, and query extensive volumes of structured and semi-structured AI usage data.You will also collaborate closely with product engineers to deliver polished, comprehensive features that address real customer challenges, including:Bundling and uploading JavaScript and Python code snippets for on-demand function calls in LLM workflows.Facilitating the parsing and uploading of attachments from LLM multimodal outputs for long-term storage.Implementing role-based access controls and data retention protocols for enterprise scenarios.

Why Choose Doppel?At Doppel, we are at the forefront of combating one of the most significant challenges posed by artificial intelligence: the prevalence of sophisticated social engineering tactics. With an alarming rise in scams, deepfakes, and other malicious attacks across various digital platforms—including websites, social media, advertisements, and encrypted messaging apps—our mission is both ambitious and vital: to create a safer internet by outsmarting these rapidly evolving digital threats.Supported by leading investors like a16z and Bessemer, and trusted by globally recognized brands such as OpenAI, United Airlines, and Coinbase, Doppel is expanding rapidly. If you are passionate about leveraging bold technology to tackle real-world challenges, we want to connect with you.Our VisionWe are developing an AI-native platform dedicated to defending against social engineering attacks.This entails creating scalable systems that continuously monitor billions of domains, social media accounts, applications, dark web forums, and more, utilizing AI agents to detect and neutralize digital threats effectively.Your RoleWe are seeking a seasoned backend engineer to design and enhance an automated system aimed at streamlining various Security Analyst functions. Our objective is to verify and neutralize threats within minutes through AI-driven automation. Recent achievements include:Developed a sophisticated LLM engine that quadrupled verification efficiency for our highest volume product line, enabling rapid takedowns at scale.Created a QA and data labeling tool to facilitate a seamless feedback loop among human analysts, machine learning models, and LLM agents.As a member of our San Francisco team (in-office a minimum of three days a week), you will:Play a vital role in developing systems that safeguard billions from AI-generated scams and digital threats.Take ownership of projects from gathering product requirements to continuously evaluating and refining released features.Mentor junior engineers, nurture a high-performance team culture, and contribute to shaping the team’s roadmap.Participate in monthly team dinners, happy hours, and social events (including outings to the Exploratorium, Valkyries games, etc.).What We Provide A mission-driven culture characterized by humility, high accountability, deep customer focus, and an abundance of exceptional talent. Complimentary lunch and dinner provided in the office. Flexible Paid Time Off (PTO).

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.

About CollateCollate is a cutting-edge AI-driven document generation platform specifically designed for the life sciences sector. Our innovative technology automates the paperwork process, enabling our clients to deliver life-saving medical innovations to patients significantly faster. As a comprehensive solution, Collate supports every phase of development for drugs, diagnostics, and medical devices—from initial concept to market launch.Our visionary CEO Surbhi Sarna, a former General Partner at Y Combinator, founded nVision Medical, which pioneered a novel method for detecting ovarian cancer before its acquisition by Boston Scientific. Our CTO Nate Smith, previously a Visiting Partner at Y Combinator and founder of Lever, leads our talented team of AI researchers, engineers, and designers who have backgrounds at industry giants such as Google, Nvidia, Meta, Netflix, Amazon, Airbnb, Hippocratic AI, and Grail. Notably, 40% of our team members are former startup founders themselves.As a compact yet highly skilled team, we have secured over $30M in seed funding from top-tier investors including Redpoint, First Round Capital, Conviction, and Y Combinator, as well as healthcare and AI leaders. This is a unique opportunity to join a company at the forefront of transformative change, guided by experienced founders with the resources to scale effectively.About the RoleWe are seeking a talented Backend Engineer who will play a crucial role in designing and scaling the systems that underpin Collate’s offerings. You will be responsible for developing APIs, services, and the infrastructure that form the backbone of our platform, ensuring they are efficient, dependable, and secure as we transition from prototypes to large-scale implementation.This position is perfect for individuals who thrive on tackling complex system challenges, flourish in an early-stage setting, and wish to see their contributions directly impact advancements in the life sciences field.Modern Tech StackCollate employs a contemporary tech stack aimed at delivering a highly reliable and available platform. Our backend services are built using Go, while we utilize Postgres as our primary database. Frontend development is powered by TypeScript and React, and Python is utilized for AI and machine learning services. Our infrastructure is hosted on AWS, employing Kubernetes for orchestration along with Terraform and Argo CD for configuration management.

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.

Join Kiddom as a Senior Backend Software EngineerAt Kiddom, we are revolutionizing the education landscape by providing a platform that champions equity and growth for all students. Our innovative approach integrates top-tier instructional materials with engaging digital learning tools, allowing schools and districts to take charge of their curriculum. With our exceptional curriculum management capabilities, we deliver personalized learning experiences that cater to the specific needs and aspirations of local communities. Our robust data insights empower educators and leaders to enhance instructional strategies, improve school programs, and foster professional development.We are seeking a dedicated Senior Backend Software Engineer to join our dynamic team, where you will play a crucial role in creating the next generation of scalable backend services. Your responsibilities will include the design, development, and maintenance of high-performance systems that underpin our applications.The ideal candidate will possess significant experience in backend technologies and system architecture, coupled with a genuine passion for addressing complex challenges faced by our users. Mentoring fellow engineers and sharing your expertise will be key aspects of this role. A strong affinity for education, an understanding of teachers' needs, exceptional product insight, and a commitment to Kiddom's mission and vision are essential.