Senior/Principal Systems Engineer - Workers AI (AI/ML)

Join our dynamic team at Cloudflare as a Senior/Principal Systems Engineer specializing in Workers AI (AI/ML). In this pivotal role, you will leverage your expertise in artificial intelligence and machine learning to develop cutting-edge solutions that enhance our platform's capabilities. You will collaborate with cross-functional teams to drive innovation a…

Join Cloudflare as a Senior Systems Engineer specializing in Workers AI, where you will play a pivotal role in shaping the future of serverless computing. You will collaborate with cross-functional teams to design, implement, and optimize systems that empower developers worldwide.In this dynamic position, your expertise will be critical in enhancing the performance and reliability of our services. We are looking for an innovative thinker with a passion for technology and a strong background in systems engineering.

Join Our Team at Air AppsAt Air Apps, we are on a mission to revolutionize resource management through innovative technology. Founded in 2018 in Lisbon, Portugal, we have expanded our reach with offices in both Lisbon and San Francisco, boasting over 100 million downloads globally. Our vision is to create the world’s first AI-powered Personal & Entrepreneurial Resource Planner (PRP), and we are looking for passionate individuals to help us achieve this goal.Our commitment to challenging the status quo drives us to push the boundaries of AI-driven solutions that make a real impact. Here, you will have the opportunity to be a creative force, developing products that empower individuals worldwide.Join us as we embark on this journey to redefine how people plan, work, and live.

About FaireFaire is a cutting-edge online wholesale marketplace driven by the belief that the future is local. Independent retailers around the world generate more revenue than giants like Walmart and Amazon combined, yet individually, they often struggle against these behemoths. At Faire, we harness the power of technology, data, and machine learning to connect this vibrant community of entrepreneurs globally. Imagine your favorite local boutique; we empower them to discover and sell exceptional products from around the world. With the right tools and insights, we aim to level the playing field, allowing small businesses to compete effectively with large retail chains and e-commerce platforms.By fostering the growth of independent businesses, Faire is making a positive economic impact in local communities worldwide. We’re in search of intelligent, resourceful, and passionate individuals to join us in driving the shop-local movement. If you share our belief in community, we would love to welcome you to ours.About this Role:We are on the lookout for a Principal ML / AI Engineer to serve as a company-wide technical thought leader and practitioner in shaping the future of Data and AI at Faire. This unique opportunity allows you to influence broad technical strategies across data, engineering, and product while engaging directly with pioneering AI research and applications. This role will report directly to the CTO of Faire.Your Responsibilities:Shape the AI Vision – Collaborate with product, design, strategy & analytics, machine learning, and the wider engineering leadership to define how AI can unlock transformational value for Faire’s retailers and brands. Provide thought leadership to guide company-wide priorities, particularly focusing on product strategy and key investment areas.Prototype and Unblock – Lead the development and implementation of AI systems (such as LLM fine-tuning, RLHF, agent frameworks, etc.) that illustrate what’s achievable and promote adoption across teams. Act as a “super individual contributor” who can delve deeply into technical challenges, enabling the engineering organization to advance quickly with AI and amplify both development and impact.Architect the AI-Ready Stack – Design Faire’s technical ecosystem, encompassing event logging, data warehouses, feature stores, and model serving, to ensure our infrastructure is AI-ready, scalable, and optimized for rapid experimentation.

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 Varomoney as a Principal AI/ML Architect, where you will lead groundbreaking projects that leverage artificial intelligence and machine learning to transform financial services. Your expertise will guide our engineering teams in developing innovative solutions that not only meet but exceed client expectations. You will be at the forefront of AI/ML technology, driving strategic initiatives and ensuring the highest standards of technical excellence.

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 Scale AI's ML platform team (RLXF) as a Machine Learning Research Engineer, where you will play a pivotal role in developing our advanced distributed framework for training and inference of large language models. This platform is vital for enabling machine learning engineers, researchers, data scientists, and operators to conduct rapid and automated training, as well as evaluation of LLMs and data quality.At Scale, we occupy a unique position in the AI landscape, serving as an essential provider of training and evaluation data along with comprehensive solutions for the entire ML lifecycle. You will collaborate closely with Scale's ML teams and researchers to enhance the foundational platform that underpins our ML research and development initiatives. Your contributions will be crucial in optimizing the platform to support the next generation of LLM training, inference, and data curation.If you are passionate about driving the future of AI through groundbreaking innovations, we want to hear from you!

ML/AI Research Engineer - Founding Team at Agentic AI LabLocation: San Francisco Bay AreaType: Full-TimeCompensation: Competitive salary + meaningful equity (founding tier)At fabrion, backed by 8VC, we are assembling a top-tier team dedicated to addressing one of the most pressing infrastructure challenges in the industry.About the RoleJoin us in shaping the future of enterprise AI infrastructure, focusing on agents, retrieval-augmented generation (RAG), knowledge graphs, and multi-tenant governance.As an ML/AI Research Engineer, you will spearhead the design, training, evaluation, and optimization of agent-native AI models. Your work will integrate LLMs, vector search, graph reasoning, and reinforcement learning, establishing the intelligence layer for our enterprise data fabric.This role goes beyond prompt engineering; it encompasses the entire ML lifecycle—from data curation and fine-tuning to thorough evaluation, interpretability, and deployment, all while considering cost-effectiveness, alignment, and agent coordination.Core ResponsibilitiesFine-tune and assess open-source LLMs (e.g., LLaMA 3, Mistral, Falcon, Mixtral) for enterprise applications, leveraging both structured and unstructured data.Construct and enhance RAG pipelines utilizing LangChain, LangGraph, LlamaIndex, or Dust, integrating with our vector databases and internal knowledge graphs.Train agent architectures (ReAct, AutoGPT, BabyAGI, OpenAgents) using enterprise task datasets.Develop embedding-based memory and retrieval chains employing token-efficient chunking strategies.Create reinforcement learning pipelines to enhance agent behaviors (e.g., RLHF, DPO, PPO).Establish scalable evaluation harnesses for LLM and agent performance, including synthetic evaluations, trace capture, and explainability tools.Contribute to model observability, drift detection, error classification, and alignment efforts.Optimize inference latency and GPU resource utilization across both cloud and on-premises environments.Desired ExperienceModel Training:Deep understanding of machine learning principles and hands-on experience with model training.

Draup, based in San Francisco, is an AI company with Series A funding that builds intelligence solutions for large enterprises. The platform analyzes over 1 billion job descriptions and 850 million professional profiles, serving more than 250 enterprise clients, including several Fortune 10 companies. Draup’s data comes from more than 100 labor databases, supporting clients with deep workforce insights. Role overview The engineering team in Silicon Valley is expanding. Draup seeks experienced AI/ML Engineers interested in advancing both research and product development in artificial intelligence. What you will do Develop and maintain production-grade large language model (LLM) pipelines and agentic workflows. Design and enhance retrieval-augmented generation (RAG) architectures at scale, using vector databases such as Pinecone, FAISS, and Weaviate. Implement advanced agentic systems with tools like LangGraph or LlamaIndex, focusing on tool use, multi-agent coordination, and reasoning loops. Lead prompt engineering, manage model versioning, oversee evaluation (including RAGAS and DeepEval), and instrument LLMOps. Integrate AI features into large-scale data pipelines, ensuring observability in production and compliance with guardrails. Location This position is based in San Francisco, CA (Silicon Valley).

Draup, a Series A-funded company in San Francisco, builds an intelligence platform that helps global enterprises make workforce and go-to-market decisions. The platform processes more than 1 billion job descriptions and 850 million professional profiles, drawing insights from over 100 labor databases. Draup supports over 250 enterprise clients, including five Fortune 10 companies. Role overview The Principal AI Architect joins a senior engineering group in Silicon Valley, focusing on advanced AI research and product development. This role shapes the technical direction for Draup’s next-generation AI systems and infrastructure. What you will do Set the architectural vision for advanced AI systems, including agent architectures, reasoning frameworks, and proprietary model development. Design and evaluate new AI capabilities such as predictive modeling, autonomous signal synthesis, and multi-modal intelligence to create valuable intellectual property. Build and maintain the technical foundation: data architecture, model serving, agent orchestration, and inference systems aligned with a long-term product roadmap. Analyze and incorporate emerging AI approaches, such as multi-agent reasoning and retrieval-augmented fine-tuning, ahead of broad industry adoption. Develop engineering standards, lead architecture reviews, and oversee documentation practices to safeguard intellectual property within the team.

Join Our Innovative Team at ArcadeAt Arcade, we are revolutionizing the way physical products are created with our cutting-edge AI platform. We empower individuals to turn their creative ideas into tangible products seamlessly, utilizing natural language and generative AI. Our mission is to democratize product design, making it as effortless as sharing a post online.Backed by a remarkable $42M in funding from industry-leading investors including Reid Hoffman and Ashton Kutcher, our company is a rising star in the tech landscape. Guided by our founder Mariam Naficy and a team steeped in AI and design expertise, we are at the forefront of a new frontier that merges AI, personal expression, and on-demand manufacturing.Your Role as an Applied AI EngineerWe are on the lookout for an Applied AI Engineer to enhance our generative AI capabilities. This position combines hands-on model development with the integration of advanced AI techniques into our production systems. You will collaborate with diverse teams to conduct research, experiment with models, and implement AI-driven products.

Welcome to Demandbase:At Demandbase, we are pioneering the only pipeline AI platform designed to empower go-to-market (GTM) teams in automating growth at scale. Our platform offers a holistic view of data, insights, actions, and outcomes, allowing B2B enterprises to effectively align and implement their account-based GTM strategies with confidence. Trusted by thousands of businesses, we help maximize revenue, reduce waste, and streamline data and technology stacks—all within a single platform.Our commitment extends beyond technology; we invest deeply in our teams, culture, and the communities we serve. Recognized continually as one of the Best Places to Work in the San Francisco Bay Area by Fortune and as one of the 60 Best Companies to Sell For by Selling Power, our offices are strategically located in San Francisco, New York, Austin, Seattle, India, and the United Kingdom.Role OverviewAs a Principal AI Software Engineer, you will spearhead the design and implementation of AI-native platforms that will transform how Demandbase develops and scales intelligent systems. Acting as a technical beacon, you will lead the evolution from traditional SaaS architectures to autonomous, agent-driven systems powered by generative AI.This is a senior-level individual contributor position with significant influence across the enterprise. You will establish architectural directions, collaborate closely with Product and Engineering leadership, and ensure our infrastructure and platforms are equipped to support large language models (LLMs), agentic workflows, and real-time AI-driven capabilities at scale.The base compensation for this position is applicable to candidates based in San Francisco, CA. For candidates located elsewhere, the base compensation will align with the primary work location, as our compensation ranges are location-specific. Actual compensation packages will reflect a variety of factors unique to each candidate, including skill set, years of experience, and depth of expertise.

Role Overview Sigma Computing is building the next generation of data interaction. The platform lets users explore and analyze billions of data rows in seconds, all within a familiar spreadsheet-like interface. Sigma aims to make it simple to analyze, present, and build data-driven applications at scale. AI is central to Sigma's vision for the future. The company is expanding its use of artificial intelligence to help users build in Sigma, surface insights, and make decisions faster. What You Will Do As a Senior AI/ML Engineer, join a team focused on shaping the AI architecture behind Sigma's platform. This work directly impacts thousands of enterprises that depend on Sigma for their data workflows. The team is responsible for designing and implementing the systems that will power Sigma's AI-driven features for years to come. Location This position is based in San Francisco, CA.

About the CompanyLavendo is a pioneering publicly traded company leading the charge in the AI revolution. With an AI-centric cloud platform, we are transforming the artificial intelligence landscape. Our state-of-the-art infrastructure, including extensive GPU clusters and advanced cloud services, supports developers in harnessing the explosive growth of the global AI industry, catering to Fortune 1000 firms, innovative startups, and AI researchers alike.Company type: Publicly tradedIndustry: AI/ML, Cloud Computing, Infrastructure-as-CodeCandidate Location: Remote U.S.Our mission is to democratize AI infrastructure access and empower organizations to innovate, optimize, and deploy AI solutions seamlessly at any scale. By simplifying the complexities of AI development, we provide a comprehensive full-stack AI platform that marries robust hardware with easy-to-use tools and services.The OpportunityWe are on the lookout for a Senior AI/ML Specialist Solutions Architect to become a crucial part of our client's dynamic team. This role presents an exciting opportunity to design and implement scalable AI solutions tailored for AI-centric clients, leveraging cutting-edge technologies and contributing to one of the most powerful commercially available supercomputers.What You'll DoArchitect and enhance distributed training and inference systems for large-scale AI models.Design and deliver customer-centric solutions that optimize performance and drive business value.Lead the migration of ML pipelines from Proof of Concept to scalable production environments.Foster long-term relationships with clients, ensuring satisfaction and alignment with their strategic objectives.Produce whitepapers, conduct technical presentations, and facilitate webinars to disseminate insights and best practices.Provide technical guidance and mentorship to teams regarding AI infrastructure and deployment strategies.Collaborate with engineering and product teams to prioritize customer feedback and shape product roadmaps.

Join DigitalOcean as a Senior Solutions Architect II specializing in AI and Machine Learning. In this pivotal role, you will leverage your expertise to design and implement innovative solutions that drive our customers' success. You'll collaborate with cross-functional teams to ensure our clients harness the full potential of our cloud services, enabling them to scale and optimize their operations effectively.

Join Our Team as an Applied AI/ML Engineer!Are you an innovative AI/ML Engineer with 5 to 8 years of experience in developing and managing production AI and ML systems that impact real users? At paraform, we seek a talented individual who thrives in creating modern LLM agentic systems and traditional ML frameworks. You should have a proven track record of delivering systems with measurable quality metrics and a tangible business impact, alongside a strong grasp of evaluation methodologies that prioritize product goals. Familiarity with large-scale retrieval, ranking, NLP, or personalization systems is highly desirable.Your ResponsibilitiesDesign and implement cutting-edge AI/ML systems that enhance matchmaking, ranking, and automation within the Paraform marketplace.Oversee the complete model development lifecycle, from data collection and labeling strategies through to deployment, monitoring, and iterative improvements in production.Collaborate closely with product managers, AI engineers, and full-stack teams to deliver systems that significantly affect marketplace metrics.Establish and sustain robust evaluation frameworks to continuously assess quality, bias, reliability, and business impact.Set the technical direction and establish best practices for AI/ML at Paraform.Mentor fellow engineers, elevating the standards of design, deployment, and maintenance of AI systems.About paraform:Paraform is revolutionizing the hiring market—one of the largest and most fragmented industries globally. We collaborate with renowned industry leaders such as Cursor, Palantir, Windsurf, Decagon, Shopify, Coinbase, and Hightouch to attract world-class talent. Our rapid growth, exemplified by an 8x increase in revenue last year, underscores our success.As the first all-in-one AI recruiting marketplace, Paraform connects companies with thousands of specialized recruiters and AI agents to streamline the hiring process, making it faster and more precise.Our mission is to enhance hiring efficiency, reliability, and scalability for every organization worldwide.At paraform, we believe the best recruiting occurs when the right talent addresses the right challenges, blending human insight with AI that comprehends hiring intricacies. Hence, we are laying a new foundation for recruitment that unites specialized recruiters with advanced AI tools.

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/

Saris AI develops applied AI solutions for the banking sector, with teams in San Francisco, Montreal, and Toronto. The company builds automation tools that handle complex, long-context reasoning and agent-driven decision-making. Reliability and compliance shape every product, and Saris AI's agents already manage real customer workflows in production. As revenue grows, the engineering team is expanding to enhance current offerings and explore new directions. The Senior Machine Learning Engineer role is based in San Francisco and sits within the core engineering group. The team works in a collaborative, early-stage setting, balancing infrastructure needs with the delivery of features that serve customers directly. What you will do Build and maintain machine learning infrastructure, such as evaluation frameworks, prompt management systems, and tools for model observability. Develop new AI features for customers while supporting and improving the underlying infrastructure. Shape strategies for evaluation, LLM routing, prompt engineering, and model selection. Set practical standards to boost quality without slowing down development. Guide technical direction by clarifying trade-offs and architectural choices. Requirements Minimum 4 years of experience in machine learning or AI engineering, including production deployment of ML systems. Direct experience with large language models, prompt engineering, evaluation techniques, and model routing. Background in building tools and systems that deliver value to users. Comfort making pragmatic trade-offs and recognizing when a solution is sufficient. Ability to navigate ambiguity, define problems, and deliver results independently. Strong focus on end users and understanding the impact of ML decisions on customer experience. Supports team growth through code reviews, collaboration, and clear technical communication. Bonus Experience in regulated industries, especially banking.

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.