Ai Tech Lead in San Francisco

Scale's LLM post-training platform team builds our internal distributed framework for large language model training. The platform powers MLEs, researchers, data scientists, and operators for fast and automatic training and evaluation of LLMs. It also serves as the underlying training framework for the data quality evaluation pipeline. Scale is uniquely positioned at the heart of the field of AI as an indispensable provider of training and evaluation data and end-to-end solutions for the ML lifecycle. You will work closely with Scale’s ML teams and researchers to build the foundation platform which supports all our ML research and development works. You will be building and optimizing the platform to enable our next generation LLM training, inference and data curation. If you are excited about shaping the future AI via fundamental innovations, we would love to hear from you! You will: Build, profile and optimize our training and inference framework. Collaborate with ML and research teams to accelerate their research and development, and enable them to develop the next generation of models and data curation. Research and integrate state-of-the-art technologies to optimize our ML system. Ideally you’d have: Passionate about system optimization Experience with multi-node LLM training and inference Experience with developing large-scale distributed ML systems Experience with post-training methods like RLHF/RLVR and related algorithms like PPO/GRPO etc. Strong software engineering skills, proficient in frameworks and tools such as CUDA, Pytorch, transformers, flash attention, etc. Strong written and verbal communication skills to operate in a cross functional team environment. Nice to haves: Demonstrated expertise in post-training methods and/or next generation use cases for large language models including instruction tuning, RLHF, tool use, reasoning, agents, and multimodal, etc. Compensation packages at Scale for eligible roles include base salary, equity,

About Glean: Glean is the Work AI platform that helps everyone work smarter with AI. What began as the industry’s most advanced enterprise search has evolved into a full-scale Work AI ecosystem, powering intelligent Search, an AI Assistant, and scalable AI agents on one secure, open platform. With over 100 enterprise SaaS connectors, flexible LLM choice, and robust APIs, Glean gives organizations the infrastructure to govern, scale, and customize AI across their entire business - without vendor lock-in or costly implementation cycles. At its core, Glean is redefining how enterprises find, use, and act on knowledge. Its Enterprise Graph and Personal Knowledge Graph map the relationships between people, content, and activity, delivering deeply personalized, context-aware responses for every employee. This foundation powers Glean’s agentic capabilities - AI agents that automate real work across teams by accessing the industry’s broadest range of data: enterprise and world, structured and unstructured, historical and real-time. The result: measurable business impact through faster onboarding, hours of productivity gained each week, and smarter, safer decisions at every level. Recognized by Fast Company as one of the World’s Most Innovative Companies (Top 10, 2025), by CNBC’s Disruptor 50, Bloomberg’s AI Startups to Watch (2026), Forbes AI 50, and Gartner’s Tech Innovators in Agentic AI, Glean continues to accelerate its global impact. With customers across 50+ industries and 1,000+ employees in more than 25 countries, we’re helping the world’s largest organizations make every employee AI-fluent, and turning the superintelligent enterprise from concept into reality. If you’re excited to shape how the world works, you’ll help build systems used daily across Microsoft Teams, Zoom, ServiceNow, Zendesk, GitHub, and many more - deeply embedded where people get things done. You’ll ship agentic capabilities on an open, extensible stack, with the craf

TextNow is on a mission to make communications affordable and accessible for everyone. As a full MVNO operating our own mobile core network over LTE and 5G NSA, we have the unique advantage of controlling our network infrastructure end-to-end. We operate the HSS, PGW, and other critical network functions, giving us the flexibility to innovate and deliver exceptional service to millions of users. About the Role We are looking for a hands-on Tech Lead, Mobile Core Network Engineering to own the health and evolution of our mobile core platform. Our cloud-hosted core runs in AWS, with our mobile core vendor providing managed services for day-to-day operations. This role is the critical bridge between our vendor’s Managed Services team and our internal engineering, product, and operations teams. You’ll be the technical owner of the mobile core, combining deep technical expertise with strong coordination skills. You won’t just manage vendor deliverables—you’ll dive into the technical details, challenge approaches when needed, and ensure our core network evolves to meet the demands of a growing subscriber base. This role has a clear growth path into technical and people leadership as the team scales. A note on background: We know that people who have operated a mobile core at scale are rare. If you’re a strong SRE or infrastructure engineering leader with deep networking knowledge and a track record of managing complex, vendor-operated platforms, we want to hear from you—even if you haven’t worked with 3GPP technologies before. We’ll invest in helping you build the telco-specific domain knowledge. What You'll Do Own the Mobile Core Platform: Take end-to-end accountability for the health, performance, and evolution of TextNow's mobile core (HSS, PGW, PCRF, and related functions running in AWS). Drive capacity plann

Airbnb was born in 2007 when two hosts welcomed three guests to their San Francisco home, and has since grown to over 5 million hosts who have welcomed over 2 billion guest arrivals in almost every country across the globe. Every day, hosts offer unique stays and experiences that make it possible for guests to connect with communities in a more authentic way. The Community You Will Join AirSupport helps Airbnb employees stay productive wherever and however they work. Within AirSupport, Executive Support provides a dedicated, high-touch technology experience for Airbnb’s senior leaders and their Executive Business Partners. The team combines deep technical expertise, proactive support, and strong cross-functional partnership across office, remote, travel, event, and other approved environments. Executive Support owns the executive technology experience, working closely with engineering, security, infrastructure, AV, workplace, and other technology partners who own the underlying technologies. The Difference You Will Make As a Senior Executive IT Support Engineer, you will be one of the most senior technical individual contributors within AirSupport and a trusted technology partner to Airbnb’s executive population. You will combine hands-on technical expertise with strong judgment, proactive planning, and cross-functional leadership. You will own complex and sensitive executive technology issues through resolution, anticipate risks before they become disruptions, and lead improvements that make the executive experience more reliable and supportable. Your impact will extend beyond the issues you personally resolve. You will identify patterns in what Executive Support is seeing, connect them to broader employee technology priorities, develop recommendations, and influence the teams responsible for the underlying technology. You will help shape Executive Support technical direction, represent the support perspective in major technology decisions, and identify opportuniti

About the Team The DoorDash Research Fellowship is a 3-month program (extendable to 6 months) looking for Summer and Fall 2026 cohorts, for researchers and engineers who want to work on the hardest applied ML and AI problems in local commerce. Fellows are given the resources, autonomy, and access to real-world operational data needed to pursue ambitious research directions — with the goal of producing work that influences both the field and how DoorDash operates at scale. This program is modeled on the best external research fellowships: fellows are treated as independent researchers, not as junior employees on a product team. You pick the problem (within a set of priority areas), you own the direction, and you publish or ship the outcome. You’re excited about this opportunity because you will receive… Dedicated compute allocation sized to the research agenda — GPU clusters for training and inference budgets for experimentation Full access to DoorDash's research infrastructure — our internal RL stack, training and evaluation pipelines, RL environments built on real operational systems, agent evaluation harnesses, and the tooling our own research teams use day-to-day. Fellows are first-class users, not sandboxed visitors. Access to DoorDash operational data — real-world datasets spanning logistics, merchant operations, consumer behavior, and marketplace dynamics, under appropriate data governance Research mentorship from senior researchers and engineering leaders at DoorDash, plus a named research sponsor for each fellow who meets with you weekly and is accountable for unblocking your work Speaker series featuring leading researchers and practitioners from academia and industry — faculty from top ML programs, research leads from frontier AI labs, and senior operators from across tech. Fellows get dedicated 1:1 time with speakers when possible. A cohort of fellows working alongside you — a small, tight-knit group of researchers tackling different problems but sharing

About Snorkel At Snorkel, we believe meaningful AI doesn’t start with the model, it starts with the data. We’re on a mission to help enterprises transform expert knowledge into specialized AI at scale. The AI landscape has gone through incredible changes since 2015, when Snorkel started as a research project in the Stanford AI Lab, to the generative AI breakthroughs of today. But one thing has remained constant: the data you use to build AI is the key to achieving differentiation, high performance, and production-ready systems. We work with some of the world’s largest organizations to empower scientists, engineers, financial experts, product creators, journalists, and more to build custom AI with their data faster than ever before. Excited to help us redefine how AI is built? Apply to be the newest Snorkeler! About the Role Snorkel AI is looking for a Head of Talent Acquisition Operations & Insights to build and lead the systems, processes, tools, metrics, and operational infrastructure that power our recruiting organization. This leader will own the design and execution of a modern TA operations function that enables Snorkel AI to scale hiring with speed, quality, consistency, and data-driven decision-making. This is a builder role for someone who has stood up TA operations in a hyper-growth technical startup environment. You should be equally comfortable designing the strategy, implementing the systems, improving process, building reporting, leading recruiting coordination, and partnering with recruiting and business leaders to improve how hiring gets done. We are looking for someone who brings strong operational discipline, deep knowledge of recruiting systems and workflows, and a forward-looking perspective on how AI can modernize talent acquisition. What You’ll Do Build and lead the TA operations function for Snorkel AI, including recruiting systems, tools, workflows, reporting, process, and coordination. Own the recruiting tech stack, including ATS configu

Software is eating the world, but AI is eating software. We live in unprecedented times – AI has the potential to exponentially augment human intelligence. Every person will have a personal tutor, coach, assistant, personal shopper, travel guide, and therapist throughout life. As the world adjusts to this new reality, leading platform companies are scrambling to build LLMs at billion scale, while large enterprises figure out how to add it to their products. To make them safe, aligned and actually useful, these models need human evaluation and reinforcement learning through human feedback (RLHF) during pre-training, fine-tuning, and production evaluations. This is the main innovation that’s enabled ChatGPT to get such a large headstart among competition. At Scale, our products include the Generative AI Data Engine, SGP, Donovan, and others that power the most advanced LLMs and generative models in the world through world-class RLHF, human data generation, model evaluation, safety, and alignment. The data we are producing is some of the most important work for how humanity will interact with AI. At the foundation of these products is the Platform Engineering team. In this role, you will lead the design and development of core data storage, streaming, caching, and indexing platforms and underlying systems. You’ll also get widespread exposure to the forefront of the AI race as Scale sees it in enterprises, startups, governments, and large tech companies. You will: Drive the architecture, design, implementation, and reliability of our foundational data platforms and systems, working closely with stakeholders and internal customers to understand and refine requirements. Collaborate with cross-functional teams to define, design, and deliver new features. Proactively identify opportunities for, and driving improvements to, current programming practices, including process enhancements and tool upgrades. Present technical information to teams and stakeholders, providing

Software is eating the world, but AI is eating software. We live in unprecedented times – AI has the potential to exponentially augment human intelligence. Every person will have a personal tutor, coach, assistant, personal shopper, travel guide, and therapist throughout life. As the world adjusts to this new reality, leading platform companies are scrambling to build LLMs at billion scale, while large enterprises figure out how to add it to their products. To make them safe, aligned and actually useful, these models need human eval and reinforcement learning through human feedback (RLHF) during pre-training, fine-tuning, and production evaluations. This is the main innovation that’s enabled ChatGPT to get such a large headstart among competition. At Scale, our products include the Generative AI Data Engine, SGP, Donovan, and others that power the most advanced LLMs and generative models in the world through world-class RLHF, human data generation, model evaluation, safety, and alignment. The data we are producing is some of the most important work for how humanity will interact with AI. At the foundation of these products is the Platform Engineering team. In this role, you will support the design and development of shared platforms used across Scale. This includes designing our foundational data platforms and lifecycle, architecting Scale’s core cloud infrastructure and orchestration stack, and redefining how engineers develop, build, test, and deploy software at Scale. You’ll also get widespread exposure to the forefront of the AI race as Scale sees it in enterprises, startups, governments, and large tech companies. You will: Drive the design, and implementation of our foundational platforms and systems, working closely with stakeholders and internal customers to understand and refine requirements. Collaborating with cross-functional teams to define, design, and deliver new features. Proactively identifying opportunities for, and driving improvements to, current p

Software is eating the world, but AI is eating software. We live in unprecedented times – AI has the potential to exponentially augment human intelligence. Every person will have a personal tutor, coach, assistant, personal shopper, travel guide, and therapist throughout life. As the world adjusts to this new reality, leading platform companies are scrambling to build LLMs at billion scale, while large enterprises figure out how to add it to their products. To make them safe, aligned and actually useful, these models need human eval and reinforcement learning through human feedback (RLHF) during pre-training, fine-tuning, and production evaluations. This is the main innovation that’s enabled ChatGPT to get such a large headstart among competition. At Scale, our products include the Generative AI Data Engine, SGP, Donovan, and others that power the most advanced LLMs and generative models in the world through world-class RLHF, human data generation, model evaluation, safety, and alignment. The data we are producing is some of the most important work for how humanity will interact with AI. At the foundation of these products is the Identity Engineering team. In this role, you will help support the design and development of core software systems specifically focused on identity, access management, authorization, and authentication. You’ll also get widespread exposure to the forefront of the AI race as Scale sees it in enterprises, startups, governments, and large tech companies. You will: Drive the design, and implementation of our identity infrastructure to ensure secure authentication and authorization across enterprise systems. Build software for authentication mechanisms such as Single Sign-On (SSO), Multi-Factor Authentication (MFA), and federated identity solutions (SAML, OAuth, OpenID Connect). Build software for authorization mechanisms such as Relation-based access control (ReBAC), Attribute-based access control (ABAC), Role-based access cont

Software is eating the world, but AI is eating software. We live in unprecedented times – AI has the potential to exponentially augment human intelligence. Every person will have a personal tutor, coach, assistant, personal shopper, travel guide, and therapist throughout life. As the world adjusts to this new reality, leading platform companies are scrambling to build LLMs at billion scale, while large enterprises figure out how to add it to their products. To make them safe, aligned and actually useful, these models need human eval and reinforcement learning through human feedback (RLHF) during pre-training, fine-tuning, and production evaluations. This is the main innovation that’s enabled ChatGPT to get such a large headstart among competition. At Scale, our products include the Generative AI Data Engine, SGP, Donovan, and others that power the most advanced LLMs and generative models in the world through world-class RLHF, human data generation, model evaluation, safety, and alignment. The data we are producing is some of the most important work for how humanity will interact with AI. At the foundation of these products is the Identity Engineering team. In this role, you will help support the design and development of core software systems specifically focused on identity, access management, authorization, and authentication. You’ll also get widespread exposure to the forefront of the AI race as Scale sees it in enterprises, startups, governments, and large tech companies. You will: Drive the design, and implementation of our identity infrastructure to ensure secure authentication and authorization across enterprise systems. Build software for authentication mechanisms such as Single Sign-On (SSO), Multi-Factor Authentication (MFA), and federated identity solutions (SAML, OAuth, OpenID Connect). Build software for authorization mechanisms such as Relation-based access control (ReBAC), Attribute-based access control (ABAC), Role-based access cont

Software is eating the world, but AI is eating software. We live in unprecedented times – AI has the potential to exponentially augment human intelligence. Every person will have a personal tutor, coach, assistant, personal shopper, travel guide, and therapist throughout life. As the world adjusts to this new reality, leading platform companies are scrambling to build LLMs at billion scale, while large enterprises figure out how to add it to their products. To make them safe, aligned and actually useful, these models need human eval and reinforcement learning through human feedback (RLHF) during pre-training, fine-tuning, and production evaluations. This is the main innovation that’s enabled ChatGPT to get such a large headstart among competition. At Scale, our products include the Generative AI Data Engine, SGP, Donovan, and others that power the most advanced LLMs and generative models in the world through world-class RLHF, human data generation, model evaluation, safety, and alignment. The data we are producing is some of the most important work for how humanity will interact with AI. At the foundation of these products is the Platform Engineering team. In this role, you will support the design and development of shared platforms used across Scale. This includes designing our foundational data platforms and lifecycle, architecting Scale’s core cloud infrastructure and orchestration stack, and redefining how engineers develop, build, test, and deploy software at Scale. You’ll also get widespread exposure to the forefront of the AI race as Scale sees it in enterprises, startups, governments, and large tech companies. You will: Drive the design, and implementation of our foundational platforms and systems, working closely with stakeholders and internal customers to understand and refine requirements. Collaborating with cross-functional teams to define, design, and deliver new features. Proactively identifying opportunities for, and driving improvements to, current p

About The Team: To help achieve our mission, we are looking for a Recruiting Coordinator to join our team. AI is rapidly changing the world, and Scale is growing to meet that rapid demand. Recruiting Coordinators who join today will help schedule and coordinate interviews, provide exceptional candidate experience, and help develop strategies that will scale alongside the new challenges we’re facing. Many of our greatest challenges are yet to be solved, and we're looking to hire a Recruiting Coordinator who is excited to tackle them. About the Role: We are looking for a talented Recruiting Coordinator on a 6 Month Contract (with possibility of extension or conversion given further business need). This is a hybrid role (3 days per week in office) based in our San Francisco or New York City office to join our team and participate in the hiring process from beginning to end. You’ll be directly working with our hiring partners, recruiters and candidates to create a personal and creative recruiting experience! You will: Schedule, coordinate, and confirm candidate interviews, handling cancellations and reschedules promptly across multiple time zones Collaborate and communicate effectively with recruiters, hiring managers, and business leaders to ensure smooth interview processes Create a welcoming and high-touch candidate experience for both virtual and in-person interviews Support Recruiting Operations on initiatives related to improving coordination workflows, candidate experience and interviewer experience Ideally you have: 1-2 years of relevant experience; scheduling high volume (100+ interview events a week) and tech industry experience are a plus Familiarity with Greenhouse, ModernLoop, or similar ATS/scheduling tools A highly organized and process-driven approach to work, ensuring SLAs are met and work is completed efficiently and accurately A curious and proactive mindset, leveraging AI tools and technology to identify opportunities for process improve

ABOUT INKHOUSE Inkhouse is part of Orchestra, a strategic communications and marketing company built for today’s complex and fragmented world. From decoding audiences to designing bold strategies, Orchestra integrates people, platforms, and stories that stick to help clients build lasting influence. The company offers programs that span from the highest level strategic business counsel through to tactical execution. Orchestra brings together 700+ people with experience across consumer and lifestyle, technology, nonprofit and philanthropy, real estate, sports, travel, hospitality, and more. Made up of leading firms BerlinRosen , Civitas Public Affairs Group , Derris , Glen Echo Group , Inkhouse , M18 , Message Lab , Onward and Small Girls PR . It also launched Brightmode , a talent acquisition firm for communications professionals, and Versus Media Group , a strategy-first political media team. Learn more at www.orchestraco.com . People of all backgrounds and abilities are strongly encouraged to apply. Orchestra is committed to building and maintaining a diverse staff, and recognizes that its continued success depends on hiring and retaining high-quality creative professionals with a variety of backgrounds and experiences. Opportunities for advancement exist, and we are committed to helping all staff develop and grow. ABOUT THIS ROLE Inkhouse is seeking an Account Manager to lead day-to-day client relations and drive strategy across a portfolio of technology clients. This is an opportunity for someone who pairs expert tactical execution with a real point of view on strategy — someone who can run the work while shaping where it's going. The Account Manager will ideally have experience across B2B and consumer technology, integrated communications spanning earned, owned and social, and a track record of high-priority media relations. This person will be a team player who keeps accounts moving to help clients achieve their goals. We're looking for candidates who are pass

Airbnb was born in 2007 when two hosts welcomed three guests to their San Francisco home, and has since grown to over 5 million hosts who have welcomed over 2 billion guest arrivals in almost every country across the globe. Every day, hosts offer unique stays and experiences that make it possible for guests to connect with communities in a more authentic way. The Community You Will Join: Providing world-class customer service for our community of guests and hosts is a critical mission at Airbnb. The Ambassador Routing & Channels (ARC) team sits within Airbnb Community Support and is responsible for powering intelligent, differentiated service experiences, ensuring every support request, across any channel, is addressed by the right expert at the right time. Our work directly drives faster resolutions, higher quality interactions, and exceptional customer satisfaction at scale. The Difference You Will Make: As a Senior Backend Engineer on the ARC team, you will contribute meaningfully across our core routing and differentiated service programs: Contribute to and lead engineering delivery on programs that enable intelligent agent matching, personalized support experiences for high-value customers, and next-generation routing and communication channel capabilities. Own and evolve core routing infrastructure, including decision engines, workflow orchestration, and routing rule management. Ensuring high availability, correctness, and scalability across millions of daily support interactions. Help drive consolidation of fragmented routing logic spread across multiple platforms and channels into a centralized, auditable, and maintainable system. Collaborate cross-functionally with Product, Operations, Data Science, and partner engineering teams to align on priorities and deliver outcomes that improve the customer support experience. Contribute to technical quality through design reviews, code reviews, and pragmatic architectural decision-making. Support the team's tech

Reddit is a community of communities. It’s built on shared interests, passion, and trust, and is home to the most open and authentic conversations on the internet. Every day, Reddit users submit, vote, and comment on the topics they care most about. With 100,000+ active communities and approximately 130 million daily active unique visitors, Reddit is one of the internet’s largest sources of information. For more information, visit www.redditinc.com . We’re looking for a highly organized, tech-savvy, and proactive litigation paralegal to join Reddit’s Legal team. In this role, you will be the primary paralegal and operational lead supporting Reddit’s Employment, IP, and General Litigation teams. This role is ideal for someone who is equally comfortable handling day-to-day matter support and scaling systems to make a growing litigation function run better. You should be excited to own core litigation support workflows, improve processes, manage discovery and preservation work-streams, and help Reddit use legal technology and AI thoughtfully to increase efficiency. Location : Hybrid. This role is remote; however, the successful candidate must be able to work from our San Francisco office approximately once a week. What You’ll Do: Serve as the lead paralegal supporting Reddit’s employment, IP, and general litigation dockets. Own core case support workflows, including matter intake, trackers, calendaring, document management, deadline tracking, and matter closeout. Coordinate with outside counsel on filings, discovery, document collection and production, invoices, and day-to-day matter administration. Own and manage Reddit’s legal hold and preservation process, including drafting legal hold notices, issuing and tracking legal holds, and managing preservation activities within various systems to ensure the preservation of potentially relevant information. Lead and assist with e-discovery matters, including initiating and managing data collections