Software Engineer - AI Agents at assembledhq | San Francisco, CA

About AssembledAt Assembled, we believe that exceptional customer support stems from a harmonious blend of human agents and AI technology. Our innovative platform serves as a unified solution that scales to meet the needs of businesses, such as Canva, Etsy, and Robinhood, ensuring seamless coordination among in-house agents, BPOs, and AI systems. With features like AI Agents capable of resolving issues from start to finish, AI Copilot for agent assistance, and an AI-driven workforce management system that enhances both human and AI efficiency, we empower teams to provide quicker, higher-quality service while making informed staffing and automation decisions. Supported by a robust $70 million investment from NEA, Emergence Capital, and Stripe, we are on a mission to redefine how AI and human collaboration functions.The TeamOur AI Products Team is at the forefront of developing autonomous AI agents designed to tackle the most complex challenges in customer support, allowing human agents to concentrate on high-value interactions. Following a successful product launch, our Assist product line achieved a remarkable 5x growth in just three months, resulting in millions in ARR, with a promising pipeline for continued expansion.We are already implementing our solutions within leading tech companies like Canva, Patreon, and Babylist, which provides us with intricate real-world scenarios and rapid feedback loops to enhance our offerings. Our engineering challenges include creating reliable autonomous agents for customer interactions, designing scalable systems across various communication channels, and pushing the limits of current LLM technology.Under the leadership of CTO John Wang, our team is committed to eradicating low-leverage support tasks and equipping agents to deliver faster and more accurate responses.Potential projects you may engage with:Scaling LLMs with GolangEnhancing RAG results with Reciprocal Rank Fusion and Hybrid SearchPioneering new LLM evaluation techniques

ABOUT THE ROLE:As an AI Engineer at Varick, you will take charge of designing and optimizing the intelligence layer within our enterprise operations. This involves creating agent systems that efficiently handle thousands of transactions, make classification decisions, and learn from human interactions.This position is suited for engineers with extensive experience in LLMs, agent architectures, and evaluation systems. You have successfully developed agent workflows that operate in production, not merely in demo environments. Your expertise includes prompt engineering, retrieval, tool calling, multi-agent orchestration, and the evaluation frameworks necessary for deploying trustworthy AI systems in enterprise settings.WHAT YOU'LL DO:• Design and implement agent architectures that tackle complex enterprise workflows, focusing on multi-step reasoning, tool calling, and exception handling.• Develop and sustain evaluation systems that ensure agent quality, accuracy, safety, and groundedness.• Create robust prompt systems, retrieval pipelines, and context engineering strategies to ensure reliable agent performance.• Establish feedback loops that empower agents to learn from human corrections and enhance their functionality over time.• Optimize inference costs and latency for production workloads to ensure efficiency.• Define and uphold best practices for agent reliability, observability, and governance.• Stay updated with the latest models, frameworks, and research to ensure impactful deployments into production.WHAT WE'RE LOOKING FOR:• At least 3 years of software engineering experience, with a minimum of 1–2 years dedicated to LLM applications or AI systems in a production environment.• Practical experience in constructing agent workflows featuring tool calling, retrieval, and multi-step reasoning.• A profound understanding of prompt engineering, context engineering, and methods to elicit reliable behavior from LLMs.• Experience in developing evaluation systems to assess AI output quality.• Proficient in Python with a solid foundation in backend engineering principles.• You have delivered AI features to actual users and have navigated challenges such as hallucinations, edge cases, accuracy drops, and cost management.• Must be based in San Francisco.

Join Deepgram, a pioneering leader in voice AI technology, as a Software Engineer specializing in Voice Agents for the restaurant industry. You will play a vital role in developing innovative AI applications that enhance customer experiences and streamline restaurant operations. Your expertise in software development and passion for AI will contribute to transforming how restaurants interact with their customers.

Join Us at Pylon as a Software Engineer - AI AgentsAt Pylon, we are revolutionizing the B2B post-sales landscape. Our comprehensive platform, driven by conversational data and advanced intelligence, empowers businesses to operate seamlessly in real-time.Supported by notable investors such as a16z, BCV, General Catalyst, and Y Combinator, we proudly serve over 1000 companies, including Linear, Cognition, Modal Labs, and Incident.io. Our inclusion in the Enterprise Tech 30 List shines a light on our impact.With a vast problem domain, we are eager to expand our team of talented software engineers to tackle the exciting challenges ahead. Your contributions will directly influence the development of our innovative solutions.Your RoleDevelop and implement the next generation of AI features at Pylon, swiftly adapting based on user feedback.Enhance the quality and efficiency of existing AI functionalities.Are You the Right Fit?If you prefer coding over meetings and value productivity, you might fit right in.Strong engineering fundamentals and efficient coding skills are essential.Autonomy excites you; you enjoy owning details and managing your projects.Located in San Francisco or willing to relocate? We value in-person collaboration as we cultivate a vibrant team culture.Our tech stack includes React, Golang, GraphQL, and AWS.Join a team of experienced engineers from prestigious companies like Samsara, Affinity, and Airbnb.What We Offer Comprehensive medical, dental, and vision coverage for employees 401(k) retirement plan Commuter benefits Parental leave 14 company holidays plus unlimited PTO Annual offsite retreats Meals and snacks provided at the office Fitness stipend

fractional-ai is hiring a Software Engineer to join the team onsite in San Francisco. This role centers on building and improving technology that advances artificial intelligence. Role overview As a Software Engineer, you will work closely with others to develop and support projects that drive the company’s AI initiatives forward. The work involves collaborating with colleagues and contributing technical solutions in a team setting. What you will do Develop software for AI-driven projects Collaborate with team members in the San Francisco office Contribute ideas and technical expertise to ongoing initiatives Requirements Interest in technology and artificial intelligence Ability to work onsite in San Francisco Strong motivation to learn and contribute to team projects

ABOUT THE ROLE:As a Full Stack Engineer at Varick Agents, you will play a pivotal role in developing the foundational infrastructure and product interfaces that drive our agent deployments. While this position is not client-facing, your contributions will ensure that each deployment is executed with enhanced speed, reliability, and consistency.This dynamic role requires you to engage with backend services, APIs, data pipelines, and user interfaces. Your responsibilities will include creating the orchestration layer for agent execution and developing the dashboards and controls utilized by clients, ensuring that every line of code you write supports real enterprise operations.WHAT YOU'LL DO:Develop and manage backend services for agent orchestration, tool activation, and workflow execution.Design and implement product interfaces for agent monitoring, human-in-the-loop controls, and client dashboards.Construct data pipelines that integrate with various enterprise systems such as ERPs, CRMs, and data warehouses.Create internal tools that expedite deployment processes and minimize engineering time for individual clients.Ensure the reliability, observability, and performance of production systems.Collaborate closely with Frontend Developers to transform client-specific solutions into reusable platform capabilities.WHAT WE'RE LOOKING FOR:At least 3 years of experience in software engineering, specifically in building production systems.Strong understanding of backend fundamentals including APIs, databases, cloud infrastructure, and distributed systems.Proficiency in full stack development, capable of creating both backend services and the UI that interfaces with them.Production experience with Python.Familiarity with cloud infrastructures such as AWS, GCP, or Azure, including containers, managed databases, and CI/CD practices.A commitment to code quality, testing, and the deployment of stable solutions.HELPFUL EXPERIENCE:Experience integrating with enterprise systems (REST/SOAP APIs, webhooks, ETL pipelines).Knowledge of large language model APIs and agent frameworks.Frontend development experience with technologies like React or Next.js.Experience with Infrastructure as Code tools like Terraform or Pulumi.Background in building multi-tenant SaaS or platform products.Experience in startup or early-stage environments.WHY VARICK:Join an innovative team at Varick Agents where you can make a significant impact through your engineering expertise.

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 Simple AIAt Simple AI, we are pioneering cutting-edge voice AI solutions tailored for enterprises. Our lifelike voice agents empower renowned companies such as DoorDash, xAI, and Omaha Steaks in managing diverse phone operations ranging from customer support to order intake and lead qualification. As we experience rapid revenue growth, we seek a couple of founding software engineers to help us meet current customer demands while developing innovative systems for the future. Our team is passionate about harnessing AI to transform the world, and we operate from our San Francisco office five days a week.Simple AI is proudly supported by top-tier investors and industry leaders, including Y Combinator, Massive Tech Ventures, and prominent figures like Michael Seibel (co-founder of Twitch), Jared Friedman (Scribd), Alexandr Wang (Scale AI), Matt Van Horn (June Oven and Lyft), Suhail Doshi (Mixpanel), JJ Fliegelman (WayUp), and Scott Wu (Cognition).Meet the FoundersThe founders, Catheryn Li and Zach Kamran, previously led software teams at Y Combinator, where they launched numerous products for YC founders, including the co-founder matching site. Cat brings experience from Instagram and Facebook and holds degrees in mathematics and computer science from MIT. Zach studied computer science and statistics at the University of Chicago and led software initiatives at PEAK6.What We ProvideCompetitive salary with significant equity opportunitiesEmployee-friendly equity termsOffice located in San FranciscoComprehensive health, dental, and vision insuranceComplimentary lunch and dinner at the officeFree Uber rides home after 8:30 PMRegular team events and offsite activitiesYour Qualifications4+ years of relevant software engineering experience.Exceptional problem-solving skills and a passion for tackling technical challenges.A customer-centric mindset coupled with strong communication skills and a keen interest in product design and prioritization.Self-motivated with the ability to work independently.A genuine enthusiasm for continual learning and keeping abreast of the latest advancements in AI.

About CartesiaAt Cartesia, we are on a mission to create the next generation of artificial intelligence—smart, interactive systems that function seamlessly in any environment. Currently, the most advanced models struggle to process and analyze extensive streams of audio, video, and text over extended periods—1 billion text tokens, 10 billion audio tokens, and 1 trillion video tokens—especially when integrated directly on devices.We are at the forefront of developing the model architectures that will enable this innovation. Our founding team, which originated from the Stanford AI Lab, is responsible for the creation of State Space Models (SSMs), a groundbreaking approach for training efficient, large-scale foundational models. Our team merges deep technical knowledge in model development and systems engineering with a product engineering group focused on design, allowing us to create and deliver pioneering models and user experiences.Supported by top-tier investors such as Index Ventures, Lightspeed Venture Partners, and others, along with guidance from industry-leading advisors and over 90 angel investors, we are well-equipped to reshape the landscape of AI.About the RoleWe are seeking a skilled Software Engineer to join our team and help propel our vision of real-time, multimodal intelligence.Your ImpactDevelop and implement a low-latency, scalable, and dependable model inference and serving framework for our innovative SSM foundational models.Collaborate with our research and product engineering teams to translate cutting-edge research into extraordinary products.Establish robust, high-quality data processing and evaluation infrastructure for training foundational models.Enjoy significant autonomy in shaping our product direction and influencing how advanced AI technologies are utilized across various devices and applications.What You BringGiven the complexity of the challenges we tackle, we prioritize strong engineering capabilities at Cartesia.Proficient engineering skills with the ability to navigate intricate codebases and monorepos.A keen eye for detail, ensuring the production of clean, maintainable code.Adaptability to new technologies and quick proficiency with our tech stack, which includes Go and Python for backend development and Next.js for frontend.Experience in building large-scale distributed systems that require high performance, reliability, and observability.

Join Our Innovative Team at Simple AIAt Simple AI, we are transforming enterprise communications through cutting-edge voice AI agents. Our highly realistic agents empower leading companies such as DoorDash, xAI, and Omaha Steaks to efficiently manage a variety of phone operations, including customer support, order processing, and lead qualification.As we experience exponential growth and a surge in customer demand, we are seeking a few founding software engineers to help us navigate this exciting journey and develop systems for the future. Our passionate team operates from our vibrant San Francisco office five days a week, driven by a shared vision of leveraging AI to make a significant impact in the world.We are proud to be backed by esteemed investors and operators, including Y Combinator, Massive Tech Ventures, and industry leaders such as Michael Seibel (Twitch), Jared Friedman (Scribd), and more.

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 a pioneering team of former Google engineers who have developed ground-breaking defensive technologies, such as Safe Browsing and reCAPTCHA. We are on a mission to confront an urgent challenge: combating the rising tide of adversarial AI attacks that threaten organizations globally.Operating in stealth mode, we are targeting a lucrative $5B+ market that is primed for innovation. Conventional detection methodologies are proving inadequate against the speed and sophistication of AI-driven assaults. Current adversaries are leveraging AI to engineer tailored, high-evasion attacks, leaving traditional systems vulnerable.Your Role:You will design a network of AI agents that are rapid, cost-effective, and precise, collaborating to identify and neutralize emerging threats. Your work will dive deep into real-time threat data, continuously evolving your agents in a fast-paced environment. These agents will function under an orchestration layer that fosters quick adaptation and learning.The Excitement of the ChallengeRapidly Evolving Models: The landscape changes daily; solutions that worked yesterday may be outdated today.Intelligent Adversaries: We are engaged in a real-time arms race against cunning, AI-enhanced attackers crafting sophisticated payloads.No Existing Playbook: We are forging new detection paradigms as swiftly as threats evolve. This high-stakes work places you in the heart of the action from day one.If you thrive on solving challenging problems with rapid feedback, this is your opportunity.Why We Are Positioned to SucceedExpansive Market: The market is vast at $5B and expanding quickly, while established players struggle to adapt.Proven Track Record: Our team has previously developed the foundational technology for Safe Browsing (serving over 5B users) and reCAPTCHA (protecting more than 5M websites) during our time at Google.Experienced Team: This is our third endeavor in creating a category-defining security enterprise, and we know how to scale our technology and our organization effectively.Deeply Integrated AI and Security: We embed AI from the outset rather than layering it on top.Top Talent: We hire only the highest achievers; many on our team were in the top 1% of engineers at Google. If you excelled in your previous role, you will fit right in.Agility: We prioritize speed and efficiency in everything we do.

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.

Biotechnology is transforming the world around us—impacting the medicines we use, the crops we cultivate, the fabrics we wear, and the essential products we depend on daily. To keep pace with the rapid advancements in science, we need cutting-edge technology.At Benchling, our mission is to harness the potential of biotechnology. The most innovative biotech firms leverage Benchling’s R&D Cloud to facilitate the development of revolutionary products, shortening the time to key milestones and market entry.Join us in revolutionizing science through modern software solutions.ROLE OVERVIEWWe are a dedicated team focused on developing AI tools for scientists, including agents that automate repetitive tasks and models that enhance molecular design. Our aim is to democratize AI accessibility, empowering every scientist to utilize these advancements. As a member of our engineering team, you will create product experiences that promote AI adoption among the vast community of scientists using Benchling. You will combine robust technical expertise with a keen product sense, optimizing onboarding processes, creating viral engagement strategies, and guiding scientists in effectively integrating AI into their daily activities. Given that we are at the forefront of scientific AI, both at Benchling and in the broader industry, we will iterate quickly based on customer feedback and adapt our strategies to discover the best pathways for development and market engagement. Our success hinges on our curiosity and commitment to our customers.

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.

Join Our Team as a Senior Software Engineer!Coval is revolutionizing the evaluation of voice and chat agents, having successfully raised a $XXM seed round (TBA), and achieving a remarkable 10x revenue increase in just two months. Our platform is in high demand, and we are eager to expand our capabilities in automated agent testing. We invite a talented Senior Software Engineer to join our dynamic team and play a pivotal role in shaping our core product.What is Coval?In an ever-evolving landscape of AI, Coval is committed to being at the forefront, providing the essential infrastructure for the future of AI agents. Our platform enables any organization to create and deploy AI agents seamlessly. While the initial wave of AI agents is captivating users, the challenge of ensuring their reliability is becoming increasingly evident. At Coval, we are dedicated to addressing these challenges.As AI adoption accelerates, testing and reliability are paramount. Coval empowers companies to design agents that not only satisfy customer needs but also perform reliably in production environments. This is just the beginning of the AI-agent era, and evaluation infrastructure will play a pivotal role in its development. Coval aims to be the leading platform for agentic testing, and we invite you to be a part of this exciting journey!Who We're Looking For:A passionate builder or ex-founder at heart.Thrives in a fast-paced startup environment, enjoying the process of building and iterating quickly.Eager to take ownership of features from conception to implementation, always prioritizing the user experience.Skilled at simplifying complex problems.Capable of designing and building systems with a clear vision for the future.What Working at Coval Looks Like:Joining Coval means becoming an essential part of a collaborative team that directly influences our product development and technical strategy. You will work closely with clients, helping them understand their unique needs, and guiding them through a seamless onboarding process while leveraging their feedback to enhance our offerings.

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 promise as a Software Engineer specializing in AI, where you will be at the forefront of technological innovation. You will work collaboratively with a passionate team to develop cutting-edge AI solutions that impact lives and improve efficiency across various sectors. Your expertise will help shape the future of our products and services.

Role OverviewLocation: San Francisco, CA Work Model: In-officeAbout Effective AIAt Effective AI, we are pioneering the future of work, focusing on sophisticated AI solutions for complex knowledge tasks rather than simple, repetitive functions. Our goal is to develop advanced AI Teammates that excel in intricate workflows and collaborate seamlessly with human professionals. Our initial challenge is to revolutionize the trillion-dollar U.S. Property & Casualty insurance sector, an area rich in data and complexity, ideal for our innovative approach.We have successfully secured $10 million in seed funding from prominent investors including Lightspeed Ventures and Valor Equity Partners.Our passionate team operates out of San Francisco, where we value in-person collaboration to address these pressing challenges.Your ResponsibilitiesAs a Founding Software Engineer, you will be an integral member of our founding team, significantly influencing the design and development of our core product from inception. You will confront critical challenges in agentic AI, crafting Teammates capable of managing essential insurance functions such as underwriting and claims processing.Specifically, you will:Facilitate long-term task completion by creating the foundational architecture for AI agents to plan and execute multi-step processes reliably over prolonged interactions.Develop advanced reasoning functionalities, enabling agents to make informed decisions based on ambiguous or incomplete information, akin to human experts.Create intelligent, tool-utilizing agents capable of selecting and employing a variety of external tools—APIs, databases, web searches, and Excel-based pricing algorithms—to gather information and take decisive actions.Design adaptive and learning systems, equipping our AI Teammates to learn from feedback and adjust to evolving conditions such as regulatory changes or market dynamics.Your ProfileWe seek an innovative and driven builder excited to tackle substantial challenges.You possess a solid foundation in computer science and remarkable problem-solving capabilities, evidenced by impactful projects or previous experience.Your genuine enthusiasm for AI fuels your passion for tackling complex issues.

Join Perplexity as a dynamic AI Software Engineer on our innovative Comet Agents engineering team. We are a tight-knit group of AI/ML specialists, backend developers, and full-stack engineers dedicated to creating engaging agentic experiences within our Comet ecosystem. Our mission is to empower users with AI agents that genuinely understand and fulfill their intents, enabling seamless, open-ended interactions with the digital world.As a key contributor to the Comet Agents team, you will apply your AI expertise, product intuition, and creative problem-solving skills to push the boundaries of what AI agents can achieve for our millions of loyal users. Your work will span applied research and engineering, tackling various challenges in AI, including:Crafting AI agents capable of navigating the digital landscape and executing valuable tasks for users;Developing action and decision models that effectively achieve user-defined objectives based on complex multimodal states;Delivering exceptional user experiences across desktop, mobile, headless cloud, and more, utilizing flexible abstractions and seamless background processes;Implementing secure-by-design capabilities through the creation of permission architectures and payload classifiers;Designing optimal data representations and interaction modes between agents and their environments;And much more!ResponsibilitiesLead the development of cutting-edge AI functionalities within our rapidly evolving AI agents product.Utilize advanced AI models, infrastructure, and browser technologies to enhance capabilities for our expanding user base.Uphold high standards of quality and performance in AI agents and user experience.Collaborate with engineers, designers, product managers, and data scientists to integrate core Perplexity functionalities into Comet agents.Contribute to product reliability, code quality, AI evaluation, testing, and ongoing maintenance across the team.QualificationsSolid foundational knowledge of the complete AI product stack.Experience with AI/ML frameworks and backend development.Proficiency in programming languages commonly used in AI development.Ability to work collaboratively in a fast-paced, interdisciplinary environment.Strong problem-solving skills and a passion for innovation in AI technologies.