Principal Engineer, LLM (Platform and Tooling)

Upstart builds AI-driven technology to make borrowing simpler and more affordable. The company partners with banks and credit unions to expand access to credit, using a platform that analyzes over a million predictions per borrower and more than 1,800 data signals to support fairer lending decisions. Most employees work remotely from across the US and Canada, with flexible options to work from home or offices in several cities. In-person gatherings help maintain strong connections. Role overview The Principal Engineer, LLM (Platform and Tooling) joins the GenAI Core Platform team. This group develops and maintains the core platform that delivers generative AI capabilities to teams throughout Upstart. The platform serves both engineers and non-engineers. In this leadership role, you will help define the vision, architecture, and rollout strategy for the new GenAI platform. What you will do Shape the technical direction and architecture for Upstart's GenAI platform Collaborate with engineering leaders, machine learning researchers, and product stakeholders Support the safe, efficient, and responsible scaling of large language models (LLMs) across the company Establish long-term direction and standards for technical excellence in GenAI and LLM work Identify and address risks for major AI projects Influence how GenAI and LLMs are adopted and implemented at Upstart Location This role is fully remote and open to candidates based in the United States.

Who We AreAt Twilio, we are dedicated to transforming the future of communications, all from the convenience of our homes. Our innovative solutions empower hundreds of thousands of businesses and enable millions of developers globally to create personalized customer experiences.Our commitment to remote-first work and a strong culture of connection and inclusion means that no matter where you are, you are part of a vibrant team that is making a global impact every day. At Twilio, we continuously learn and evolve in our approach to work, ensuring that your career path is in your hands.We utilize Artificial Intelligence (AI) to streamline our hiring process, maintaining efficiency and fairness, but every hiring decision is ultimately made by real Twilions, ensuring a personal touch at every step.See Yourself at TwilioJoin us as a Principal Product Manager on the Console & API team, leading product development for Console Copilot backend services and AI agent platforms.About the JobThis is a high-impact leadership role focused on driving the strategy and execution of Twilio’s Copilot Backend Services. You will build foundational AI orchestration engines that empower Twilio’s intelligent agents—the virtual experts serving our customers across the Twilio Console and various support channels.As a Principal PM, you will define how our backend services absorb extensive Twilio-specific product knowledge, documentation, and real-time telemetry to offer proactive assistance and conversational support. Your mission is to transition from static help documentation to a dynamic environment where our backend anticipates customer friction and resolves it autonomously. You will ensure that these agents are high-performing, contextually aware, and seamlessly integrated into the customer journey from sign-up to global scale.

Since our inception, Fivetran has been committed to simplifying and ensuring reliable access to data—making it as straightforward as turning on a light. Our platform seamlessly integrates customer data into warehouses, fully prepared for analysis without the need for internal engineering efforts. We take pride in empowering organizations daily to harness the full potential of their data.About the RoleAt Fivetran, we are developing data pipelines to support the modern data stack for numerous businesses.We are on the lookout for a distinguished Principal Software Engineer to spearhead our AI adoption strategy within the Engineering division. This pivotal leadership role merges extensive technical know-how with strategic business insight and change management skills. You will be the catalyst for transforming our cohort of over 500 engineers into 'Bionic Engineers' while deploying Virtual Engineer functionalities to realize a 10% productivity increase in FY26 and 20% in FY27.As the primary contact for AI initiatives within Engineering, you will lead a comprehensive transformation that embeds AI-driven productivity as a fundamental engineering skill. This role demands an individual adept at navigating the fast-changing AI landscape, fostering adoption across varied teams, and delivering significant business results.This full-time, hybrid role is based in our Oakland, CA office. Our hybrid model provides a mix of remote flexibility and in-person collaboration, requiring two days in the office each week to promote teamwork and connection.Technologies You’ll UtilizeJava, Postgres, Oracle, SQL Server, MySQL, Kubernetes, Docker, AWS, GCP, CircleCIGoogle Gemini, Anthropic Claude, Claude Code, ChatGPT, OpenAI Codex, GitHub CopilotYour ResponsibilitiesAdoption Management & Leadership (40%)Drive Cultural Transformation: Lead the...

At Fastly, we empower individuals to maintain meaningful connections with the things they cherish. Our cutting-edge edge cloud platform allows customers to deliver exceptional digital experiences with speed, security, and reliability by processing and securing applications as close to end-users as possible — right at the edge of the Internet. Our platform is engineered to harness the potential of the modern internet, enabling programmability and supporting agile software development. We proudly serve some of the world's most influential companies, including GitHub, Yelp, Paramount, and JetBlue.Join us in building a more trustworthy Internet.Posting Open Date: Reposted March 30, 2026Anticipated Posting Close Date*: April 20, 2026*This job posting may close earlier due to high applicant volume. Senior Principal Engineer, Platform EngineeringAs a member of Fastly’s Platform Engineering team, you will be instrumental in establishing the essential frameworks that enable engineers to deliver quickly, safely, and at scale. In the role of Senior Principal Engineer, you will guide the technical direction and spearhead cross-organizational initiatives aimed at enhancing our platform, developer experience, and operational excellence. Collaborating closely with fellow engineers, you will work to eliminate friction, standardize best practices, and create paved roads to expedite product delivery. This is a highly collaborative and hands-on position, representing the Platform Engineering organization and reporting directly to the Senior Director of Engineering.

Join Whatnot as an LLM Platform Engineer where you'll be at the forefront of developing and optimizing cutting-edge language models. In this role, you will collaborate with a dynamic team of engineers and data scientists to enhance our machine learning infrastructure and algorithms. Your contributions will directly impact the efficiency and effectiveness of our language understanding capabilities.

At ClickUp, we are not merely developing software; we are shaping the future of work! In an era dominated by work sprawl, we envisioned a better path forward. This vision led to the creation of the first truly integrated AI workspace that seamlessly combines tasks, documents, chat, calendar, and enterprise search, all enhanced by context-driven AI. Our goal is to empower millions of teams to break free from silos, reclaim their time, and achieve unprecedented levels of productivity. Join us at ClickUp to explore, innovate, and lead the charge in utilizing AI to redefine not just our product, but the future of work itself. ClickUp is a rapidly growing SaaS company that has built an all-in-one productivity platform. By unifying project management, document collaboration, and communication tools, we support over 20 million users and thousands of teams in working more efficiently. With over $300 million in annual recurring revenue (ARR), we are scaling swiftly while tackling complex technical challenges to serve our global user base.The Opportunity:We are seeking a transformative technical leader to take ownership of the architectural vision for our core collaborative tools. Your leadership will set new benchmarks for performance and reliability for our enterprise clients.This role revolves around distributed systems. You will be responsible for the foundational architecture that enables millions of concurrent users to collaborate with minimal latency. Your expertise in real-time systems—covering aspects like state consistency, concurrency models, and the nuances of CRDTs and operational transforms—will be crucial.This position is not designed for a theoretical architect; rather, it offers a hands-on opportunity to evolve a complex, established architecture into a world-class, cohesive platform. You will identify and resolve critical, cross-system issues, devise a realistic strategy to modernize our core systems, and lead by example. Your success will be gauged by the measurable enhancement in our product's performance and the enduring positive influence you have on ClickUp’s engineering culture.What You Will Do:Spearhead the long-term technical strategy for ClickUp’s core collaboration platforms, encompassing real-time editing, live canvases, file uploads, and media streaming.Address our most complex architectural challenges by delving deeply into our entire tech stack (Angular, Quill, WebSockets, Yjs, NodeJS, PostgreSQL, AWS).Foster operational excellence organization-wide by implementing architectural practices that enhance performance and reliability.

About SaviyntAs a frontrunner in identity security, Saviynt provides an innovative AI-driven platform that governs and secures access to applications, data, and business processes for some of the largest enterprises and government institutions worldwide. Designed for the AI era, Saviynt empowers organizations to accelerate their operations—securely and in compliance with regulations. Importance of This RoleThe reliability and performance of Saviynt’s platform is crucial to our customers. As we expand globally, these attributes are not just desirable—they are fundamental features of our product.As a Principal Engineer, you will spearhead the reliability strategy for our SaaS platform. This impactful, hands-on engineering position will have a significant influence across infrastructure, platform, and application teams. You will play a key role in shaping how Saviynt designs, operates, and evaluates reliability on a large scale.This position is perfect for engineers eager to tackle complex reliability challenges, influence team architecture, and make a meaningful contribution to a rapidly growing SaaS platform. Your ResponsibilitiesIn this critical role, you will design, build, and maintain the shared infrastructure services and platforms that support our product and application teams.You will create reusable, reliable, and scalable solutions that simplify complexity, allowing other teams to concentrate on their core business logic and expedite feature delivery in a multi-cloud environment.You will design and implement core platform components and shared infrastructure services that other development teams will integrate and utilize to deploy and manage their applications.Architect, implement, and oversee highly available and scalable Kubernetes platforms as a service for internal users.Develop robust internal tools and automation for infrastructure provisioning and management, primarily leveraging Go (Golang).Architect and optimize foundational solutions within cloud environments (AWS, Azure, etc.), focusing on creating reusable patterns and modules for other teams.Design and implement shared Event-Driven Architecture components and messaging platforms using technologies like Kafka or Google Pub/Sub for product teams to easily leverage.Develop and maintain robust CI/CD pipelines (e.g., GitLab CI and ArgoCD) as a service, offering standardized and automated deployment workflows for various development teams.Design and build resilient Distributed Systems components that act as building blocks for other applications, emphasizing reliability, fault tolerance, and performance.

Join the innovative team at REEKON Tools, where we are dedicated to empowering the next generation of construction and home improvement professionals. Our mission is to help them accomplish their tasks more efficiently and accurately than ever before. At REEKON Tools, we are rapidly developing and launching groundbreaking hardware products that are redefining the power and hand tool industry. We are proud to be at the forefront of professional tools and equipment.As a Mechanical Design Engineer, you will collaborate closely with our talented engineering team to bring cutting-edge hardware products to market. You will play a vital role in advancing products from R&D through to manufacturing, working across multiple product lines with a high degree of autonomy and ownership.

At Blue River Technology, we are a pioneering team dedicated to developing intelligent machinery that addresses significant challenges faced by our customers. Our mission empowers farmers, construction teams, and foresters to adopt safer and more sustainable practices, enhancing profitability while minimizing dependence on limited labor resources. We emphasize the importance of meticulous attention to detail—small adjustments lead to substantial improvements. Aligning with John Deere’s vision to “innovate on behalf of humanity,” Blue River Technology excels in swiftly identifying and addressing high-value, uncertain challenges in AI, machine learning, computer vision, and robotics. As a driving force in research and development, we create not only innovative products but also robust platforms that consistently deliver value to both Deere and its customers. From fully autonomous machinery to precision farming tools, our collaboration with Deere aims to achieve groundbreaking advancements in agriculture and construction sectors. Position Overview We are on the lookout for a Principal Platform Engineer who will play a crucial role in providing technical leadership for our Computer Vision, Machine Learning (CVML), and Robotics Data Platform. This position focuses on enhancing data enablement throughout the robotics development lifecycle. You will be responsible for building and evolving APIs, applications, pipelines, and visualizations that empower Machine Learning Engineers (MLEs), Data Scientists (DS), and others involved in robotics development to operate efficiently at scale. This is a hands-on leadership role where you will serve as a technical lead and mentor to Senior and Staff Engineers, establish technical direction, and oversee the execution of complex, cross-functional initiatives. While people management is an option, it is not a core requirement of this role.

Join Pinterest as a Principal Engineer for our Compute Platform, where you'll play a crucial role in driving the architecture and implementation of scalable systems that power our services. You will lead a team of talented engineers, guiding them in building innovative solutions that enhance our platform's performance and reliability.In this position, you will have the opportunity to collaborate with cross-functional teams, mentor junior engineers, and contribute to the development of best practices and high-quality code. If you are passionate about technology and eager to make an impact, we would love to hear from you!

Role overview Clarity Innovates seeks a Lead Principal Platform Engineer to design and build core platform solutions. This fully remote position centers on developing systems that drive both growth and operational efficiency. The role involves close collaboration with a talented team, shaping architectures that can scale as needs evolve. What you will do Lead the design and implementation of platform solutions that serve as the foundation for company products and services Work with engineers and stakeholders to develop systems that scale effectively Contribute to setting technical direction and standards for platform architecture Remote collaboration This position operates remotely and involves working with distributed teams across different locations.

SummaryWe are seeking a dynamic and highly skilled Principal Software Engineer to join our Unreal Mission Tools team in San Rafael. In this pivotal role, you will develop systems and tools in Unreal Engine 5 that will facilitate the creation of immersive story and open-world missions or quests. Your contributions will empower designers and scripters to craft compelling content, as well as create the necessary tools to manage extensive player experiences. The systems you design will be utilized by a diverse range of professionals including designers, engineers, and QA, interacting across various disciplines throughout the studio.

Encora is seeking a Principal Engineer with deep experience in Data and ML Platforms to join the team in Scottsdale, AZ. This role centers on designing and building the core data infrastructure that powers the company’s AI and machine learning products. Role overview This is a hands-on technical leadership position. The Principal Engineer will architect scalable, cloud-native infrastructure to support both real-time and batch data services. These services are vital for machine learning training, inference, and feedback processes. Key responsibilities Lead the design and development of foundational data and ML platform components Define the technical direction for the platform’s architecture and capabilities Collaborate with AI Platform, MLOps, and backend engineering teams to align on solutions Collaboration This position works closely with cross-functional teams to ensure the data and ML infrastructure meets current and future needs. The Principal Engineer will influence key decisions and help shape the platform’s evolution.

About SaviyntSaviynt stands at the forefront of identity security, offering an innovative AI-driven platform designed to manage and safeguard access to applications, data, and essential business processes for some of the largest enterprises and government entities worldwide. As organizations navigate the complexities of the AI era, Saviynt empowers them to accelerate operations while ensuring security and compliance.Why This Role MattersThe reliability and performance of Saviynt’s platform are vital for our customers. As we expand our global footprint, these attributes are not merely desired; they are fundamental to our product's success.In your role as a Principal Engineer, you will be pivotal in shaping and implementing the reliability strategy for our SaaS platform. This high-impact, hands-on engineering position offers extensive influence across infrastructure, platform, and application teams, allowing you to significantly impact how Saviynt designs, operates, and measures reliability at scale.This opportunity is perfect for engineers eager to tackle challenging reliability issues, influence architecture across teams, and leave a lasting legacy on a rapidly growing SaaS platform serving the Federal sector.Your ResponsibilitiesIn this critical position, you will be instrumental in designing, building, and maintaining the shared infrastructure services and platforms relied upon by our product and application teams.Ensure effective vulnerability management while holding teams accountable to meet customer-facing Service Level Agreements (SLAs).Design Continuous Delivery (CD) processes specifically for government deployments with future commercial applications.Create robust internal tools and automation for infrastructure provisioning and management, primarily utilizing Go (Golang) or Python.Architect and optimize foundational solutions within Cloud environments (AWS, Azure, etc.), focusing on reusable patterns and modules for other teams.Design and implement shared Event-Driven Architecture components and messaging platforms using technologies such as Kafka or Google Pub/Sub for ease of use by product teams.Build resilient Distributed Systems components that act as foundational elements for other applications, emphasizing reliability, fault tolerance, and performance.Manage and optimize our shared infrastructure across Multi-Region Cloud Environments, ensuring global availability and performance of platform services for all users.Establish and enhance centralized Observability and Monitoring platforms and tools that deliver self-service insights for consuming teams.Define and implement clear, well-documented RESTful API designs for the infrastructure services you develop, ensuring seamless integration.

About SimpliSafe At SimpliSafe, we are at the forefront of high-tech home security, driven by our mission to safeguard every home. We have cultivated a culture that not only cherishes the safety of our clients but also values the career development of our team members. In our no-ego environment, collaboration and innovation thrive, creating ample opportunities for those ready to face new challenges and make a significant impact on the lives we protect. We don’t just want you to work here; we want you to flourish. Our hybrid work model allows our teams to balance office and home working seamlessly. Expect to collaborate in our state-of-the-art Boston office on two core days—typically Tuesday, Wednesday, or Thursday—while enjoying the flexibility to choose your workspace for the remaining days. This approach allows us to harness the benefits of both environments to optimize productivity. Why We Are Hiring We are expanding our Tools and Automation organization, specifically within the Test Platform Services (TPS) team. TPS is responsible for building and managing the platforms and automation that validate the comprehensive SimpliSafe ecosystem, which includes connected cameras, sensors, base stations, firmware, cloud services, monitoring workflows, and mobile applications. Our goal is to enable scalable, production-like validation across hardware, firmware, and distributed software systems. This ensures our devices perform accurately in real-world conditions and that essential customer journeys operate reliably before they are deployed to production. We are on the lookout for a Software Engineer who can lead the technical vision for TPS while managing a team of engineers. This position merges hands-on architectural responsibilities with leadership and mentorship, offering a unique opportunity for those looking to make a significant impact. This role is highly collaborative, requiring close partnerships with Infrastructure, Backend, Firmware, and Monitoring teams to ensure our validation platforms evolve in line with product and system complexity. It’s perfect for a leader who wishes to stay technically involved while shaping a high-performing engineering team dedicated to validating complex, distributed systems at scale. Your Responsibilities Establish and implement the long-term architectural vision for scalable validation platforms, with a focus on automation, performance, and resilience testing capabilities. Collaborate cross-functionally with Infrastructure, Backend, Firmware, Monitoring, and Product teams to ensure alignment of validation systems with product architecture, roadmaps, and business objectives. Guarantee that virtual devices and simulation systems accurately represent real-world hardware behavior, minimizing discrepancies between physical and virtual environments.

Join versant3 as a Principal Software Engineer for Data Platforms, where you will lead innovative projects that shape the future of data technology. In this pivotal role, you will architect, design, and implement robust data solutions while collaborating with cross-functional teams to drive technical excellence.

Join New Relic as a Principal Software Engineer within our Developer Platform team, where you will play a pivotal role in shaping our software solutions. As a key contributor, you will design and implement robust systems that empower developers to innovate and create exceptional applications.

Join our innovative team at Foundation LLM Technologies, an MIT-originated and venture-backed startup situated in the heart of Silicon Valley. We are on a mission to create a groundbreaking AI Copilot for design and manufacturing, resembling a real-life 'Jarvis'. By harnessing cutting-edge artificial intelligence, advanced physics simulations, and state-of-the-art computer graphics, we aim to lower costs and enhance engineering productivity throughout the entire design and manufacturing lifecycle.

Become a pivotal part of REEKON Tools as we revolutionize how construction and home improvement professionals execute their projects with enhanced speed and precision. We are at the forefront of innovation, rapidly developing and launching cutting-edge hardware products across the power and hand tool sectors, solidifying our reputation as leaders in professional tools and equipment.As an Embedded Firmware Engineer, you will engage in diverse projects aimed at expanding our embedded codebase and significantly contributing to the development of our next-generation consumer products. REEKON Tools boasts active products at various development stages, from early R&D to supporting tools already in the hands of thousands of skilled professionals. In this hands-on position, you will collaborate closely with our engineering team to create new hardware prototypes tailored for a wide array of construction and home improvement applications, taking on both contributory and leadership roles.The ideal candidate will possess experience in taking consumer electronics or comparable products from prototype through to mass production in a practical setting. This role entails both architectural and execution tasks related to hardware product development. Our standards are exceptionally high, matched only by our enthusiasm and commitment to disrupting the construction industry. A portfolio showcasing your work will be highly regarded for this position.To submit your application, please apply here and send an email to careers@reekon.tools detailing the project you are most proud of from your personal or professional journey.

Join us as a pioneering member of a brand new, globally distributed team on a mission to transform the internal developer experience within a large technical organization comprising thousands of developers. You will leverage AI-driven developer tools to innovate and enhance productivity.