Senior / Staff Software Engineer at fractional-ai | San Francisco

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.

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

Join Fractional AI as a Forward Deployed Product ManagerAt Fractional AI, we specialize in developing personalized Generative AI software that revolutionizes business operations. Collaborating with notable clients like Zapier, Airbyte, and Change.org, we create impactful AI applications tailored to meet their unique needs.As organizations strive to bridge the divide between theoretical AI and its practical applications, we facilitate this transition with our exceptional engineering capabilities and comprehensive AI solutions. Explore our case studies to see how we make a difference.We are a profitable, rapidly growing company dedicated to tackling the most challenging problems in applied AI.About the RoleAs a Forward Deployed Product Manager, you will engage with clients who present ambitious goals—such as enhancing content moderation efficiency, improving customer service, unlocking new integrations, and automating complex workflows. Your mission will be to transform these objectives into tangible AI-driven solutions that deliver real-world results, guiding the process from initial discussions to deployment and measurable business impact.This role encompasses several key functions:Client Engagement: Acting as the primary liaison between Fractional AI and our clients.Product Strategy: Defining product development priorities and rationales.Project Management: Overseeing the execution of projects from start to finish.Operational Flexibility: Taking initiative to address any gaps that arise during the product lifecycle.Your Responsibilities:Manage Customer Relationships:Serve as the strategic partner for clients, maintaining regular communication.Participate in initial discussions, facilitate discovery sessions, gather feedback, and ensure alignment on project objectives.Establish trustworthy connections with stakeholders at all levels, setting realistic expectations and transparently discussing trade-offs.Define Product Vision:Determine product features, refine project scope, and prioritize the most impactful use cases.Translate complex business challenges into clear, actionable project plans.

About Fractional AIAt Fractional AI, we specialize in creating tailored generative AI software that revolutionizes businesses.In today’s landscape, C-suite executives across the nation are striving to bridge the divide between theoretical AI and practical application. We facilitate this transition with our outstanding engineering talent and bespoke end-to-end AI solutions. Explore some of our case studies to discover more about our impact.Joining Fractional AI means becoming part of a dynamic team located in San Francisco and NYC, working on innovative generative AI projects for leading companies, all within the atmosphere of an engineering-centric startup.About Bringing Your Own Engineering TeamWe understand that the right team can significantly amplify our capabilities, fostering collaboration and driving collective achievement. If you are part of an existing group of 2-5 engineers—perhaps you co-founded your own venture or have been affected by layoffs—we invite you to apply to join Fractional AI as a team.We will coordinate your interviews for the same day, and should we extend an offer, it will be to all team members simultaneously. Each of you will have the freedom to accept or decline individually, but we hope you will all join us, after which we will collaborate to identify initial projects at Fractional AI where you can work together.As a member of Fractional AI, you will take a pivotal role in developing and launching AI applications for our first clients—from comprehending customer requirements to deploying solutions in their environments—all while contributing to the evolution of our Engineering team and the broader culture at Fractional AI as we grow to over 100 engineers.

Join Fractional AIAt Fractional AI, we specialize in creating tailored generative AI software that revolutionizes businesses. Our mission is to bridge the divide between theoretical AI and its practical applications, leveraging our exceptional engineering talent to deliver custom end-to-end AI solutions. To explore our success stories, please check out our case studies.By becoming a part of Fractional AI, you will join an innovative, in-person team located in San Francisco and NYC, where the dynamic atmosphere of a startup meets the potential to make a significant impact on millions of users. We are a diverse and curious group of achievers seeking talented individuals who are driven, collaborative, and results-oriented.Your RoleWe understand that conventional job descriptions may not fully capture your potential. At Fractional AI, we are always on the lookout for remarkable talent. We invite you to share your unique vision on how you can contribute to our team.Why You Should Consider Joining UsWe value transparency and recognize that choosing a company is a significant decision. Fractional AI may not be the right fit for everyone, and we strive to communicate who we are clearly.Reasons to Join Fractional AI:Experience AI in Action: Gain firsthand insights into how leading companies deploy AI solutions.Tackle Real Challenges: Collaborate on solving complex problems that many organizations face, ensuring a stimulating work environment with continuous learning opportunities across various industries.Learn from Industry Leaders: Work closely with a team comprised of successful founders, including Travis May, former CEO of LiveRamp and founder of Datavant, in an environment that fosters collaboration and creativity.Reasons Not to Join Fractional AI:Need for Predictability: If working across diverse projects and industries isn't your preference, this role may not suit you.Preference for Routine: Expect a non-repetitive experience, as you will engage with different clients and challenges regularly.

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.

Join Fractional AI as an Associate Principal of AI TransformationAt Fractional AI, we specialize in creating tailored generative AI software solutions designed to revolutionize businesses. Our clients include private equity-backed companies and Fortune 500 enterprises across diverse industries.As AI continues to evolve, every C-suite executive is grappling with the challenge of translating theoretical AI into practical applications. Our elite engineering team excels at developing comprehensive AI solutions, while our top-tier business team offers expert AI advisory services. We are on a fast-paced growth trajectory, positioned at the cutting edge of applied AI, collaborating with some of the world's largest private equity firms.We seek intellectually curious, collaborative professionals eager to make an impact from day one.Role OverviewAs an Associate Principal, you will serve as the intellectual backbone of our AI due diligence practice. Your responsibilities will include assessing disruption risks and identifying value creation opportunities across various industries, conducting management interviews, and presenting your insights to our private equity clients. Each quarter, you'll gain insights into 4-5 companies, honing a unique pattern recognition that is unmatched in the market.This exposure will pave your way to becoming a Principal at Fractional AI, the go-to advisor for private equity firms seeking AI guidance for their portfolio companies. In addition to diligences, you will collaborate with our Principals on active deals, proposals, and fostering relationships within the private equity sector. Within 6-12 months, you will be expected to begin leading your own deal pursuits.Note that this position does not have sales quotas but is designed to evolve into one.Key ResponsibilitiesLead end-to-end diligence processes. You will be fully dedicated to each engagement while the Principal and AI Architect manage multiple deals. As the primary point of contact, you will maintain a sharp point of view, prepare the team for each interview, and ensure the Principal is thoroughly prepared for client meetings. Your role encompasses desk research, generating points of view, conducting interviews, and overseeing deliverables.Assist with live deals and account management. You will work closely with Principals on ongoing sales efforts, participating in discovery calls, shaping proposals, and managing existing customer relationships.Develop your network within private equity. This role provides a unique opportunity to connect with key players in the private equity industry, enhancing your professional footprint.

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.

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.

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 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 Fractional AIFractional AI specializes in creating tailored generative AI software that drives business transformation.In a landscape where every C-suite is striving to connect theoretical AI with real-world applications, we bridge that divide with top-tier engineering talent and bespoke AI solutions. Explore our case studies for further insights.We are a profitable company experiencing rapid growth, dedicated to tackling the most challenging issues in applied AI.About the RoleWe are on the hunt for a dynamic and exceptionally dependable generalist eager to contribute to building a groundbreaking company. You will spearhead special projects and initiate new strategies that will facilitate the scaling of Fractional AI.This is a fast-paced role in a hypergrowth environment, where each day brings new challenges. One week, you might engage in market research for potential acquisitions; the following week, you could be managing strategic partnerships with foundational model companies.This position involves a blend of strategy, execution, and daily problem-solving, with no existing playbook.

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.

About Fractional AIFractional AI specializes in creating customized generative AI software solutions that revolutionize business operations.Our mission is to help organizations transition from theoretical AI concepts to practical applications. We achieve this by leveraging top engineering talent and delivering tailored end-to-end AI solutions. To see our impact, check out our case studies.Based in San Francisco and New York City, we are a profitable engineering-driven startup experiencing over 100% quarter-over-quarter revenue growth, and we are just beginning our journey.Role OverviewAs a pivotal member of our talent acquisition team, you will play a crucial role in attracting, assessing, and building a high-performing team. You will help design our recruitment strategy for our next 100 hires.Key Responsibilities:Talent Sourcing: Employ various strategies, from outreach campaigns to networking events, to discover exceptional full-stack engineers for Fractional AI.Candidate Partnership: Guide candidates throughout the recruitment process—from initial conversations to job offers—ensuring a deep understanding of their skills and aspirations.Exceptional Recruitment Process: Lead a recruitment strategy that prioritizes inclusivity, data-driven insights, and a remarkable candidate experience.Employer Branding: Serve as a brand ambassador for Fractional AI, influencing how we attract and engage top engineering talent.Qualifications:Proven Track Record: Demonstrated success in recruiting Staff, Principal, and Senior Engineers, particularly within early-stage companies.Empathetic Communication: Ability to quickly connect with others, fostering trusted relationships with candidates and hiring managers alike.Data Orientation: Strong analytical skills to support recruitment decisions and improve processes.

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.

About UnifyUnify is revolutionizing the way revenue teams operate by developing the first AI-powered system of action. Our mission is to transform outbound strategies into a robust growth engine, ensuring that go-to-market execution is observable, repeatable, and scalable. Established in 2023 by industry leaders from Ramp and Scale AI, our talented team boasts backgrounds from renowned companies like Airbnb, Meta, Waymo, and Perplexity.In 2024, Unify achieved an impressive 8x revenue growth and serves a diverse clientele including Perplexity, Cursor, SoFi, and Justworks. We are a dynamic team fueled by high energy and intensity, having secured $58M in funding from leading investors such as Thrive, Emergence, and OpenAI. Join us in shaping the future of GTM!About the Role:As a Senior Software Engineer specializing in AI at Unify, you will be at the forefront of innovation, developing new AI products and enhancing our AI platform. Your work will encompass agents, retrieval systems, classification, fine-tuning, reinforcement learning, and LLM inference infrastructure. If you are passionate about creating production-ready AI systems and wish to contribute to cutting-edge applications used by premier GTM teams, this role is for you.

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/