Staff Backend Software Engineer - AI Platform

ABOUT RETELL AIAt Retell AI, we are revolutionizing the call center experience using cutting-edge voice AI technology. In just 18 months since our inception, thousands of companies have leveraged our AI voice agents to streamline sales, support, and logistics operations that previously required extensive human teams. Supported by prominent investors such as Y Combinator and Alt Capital, we have grown from $5M to an impressive $36M ARR with a dedicated team of 20.Our ambitious vision for 2026 is to create a state-of-the-art customer experience platform where entire contact centers are driven by AI. Rather than relying on basic automation that necessitates constant human oversight, we are developing intelligent AI “workers” to function as frontline agents, QA analysts, and managers—constantly executing, monitoring, and enhancing customer interactions.As we rapidly expand, we seek passionate innovators eager to solve complex technical challenges, move swiftly, and make a meaningful impact at one of the fastest-growing voice AI startups. Join us in building the future!Ranked among the top 50 AI applications in the a16z list: https://tinyurl.com/5853dt2xRanked #4 on Brex's Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025One of the top startups on the Leana I leaderboard: https://leanaileaderboard.com/THE ROLEWe are in search of a Principal/Staff Engineer to spearhead the technical direction of our core platform. This is an individual contributor role designed for someone who excels in uncertainty, acts swiftly, and elevates the standards of those around them.You will engage with various systems, infrastructure, and product surfaces while collaborating closely with engineering teams, product managers, and leadership to scale successful initiatives and innovate for the future.This role is not about merely addressing tickets; you will identify challenges, engineer solutions, and deliver impactful results.KEY RESPONSIBILITIESLead the design and evolution of our core platform and systems architecture.Oversee complex technical projects from inception to production.Make strategic technical decisions that optimize for speed, reliability, and scalability.Collaborate across teams to facilitate knowledge sharing and best practices.

At ClickUp, we are not just creating software, we are crafting the future of work! In a landscape saturated with work complexities, we envisioned a better solution. This vision led to the development of the first genuinely integrated AI workspace, seamlessly combining tasks, documents, chat, calendar, and enterprise search, all enhanced by context-sensitive AI. This empowers millions of teams to break down barriers, reclaim their time, and elevate productivity to new heights. Here at ClickUp, you will have the chance to learn, leverage, and innovate with AI in ways that will not only transform our product but also redefine the future of work itself. Join us in being part of a daring, innovative team that is reshaping possibilities! Role Overview:We are in search of a highly talented and experienced Staff AI Engineer – AI Platform to become a vital member of our ClickUp Engineering team. In this pivotal role, you will significantly contribute to the development of our core AI platform and directly utilize large language models (LLMs) to implement intelligent features across ClickUp. Your focus will be on back-end systems that facilitate scalable, dependable, and secure AI-driven capabilities, while also engaging hands-on with LLMs to address real user challenges and propel product innovation.Key Responsibilities:Design, architect, and implement scalable AI platform services to support the deployment, orchestration, and lifecycle management of LLMs and other AI models.Utilize LLMs and other AI technologies to build and enhance ClickUp’s intelligent features, collaborating closely with product and engineering teams to deliver impactful solutions.Develop and maintain robust APIs and backend systems that facilitate seamless integration of AI-enhanced features into ClickUp’s core platform.Create infrastructure for model serving, monitoring, logging, and automated evaluation to ensure high reliability and performance of AI services in production.Integrate with various LLM providers (e.g., OpenAI, Anthropic, Google) and manage model selection, routing, and fallback strategies for optimal performance and cost-efficiency.Promote best practices in AI privacy, security, and compliance, including data anonymization and secure data handling.Optimize platform performance, scalability, and cost-efficiency, utilizing cloud-native technologies and distributed systems.Stay abreast of advancements in AI infrastructure, MLOps, and LLM applications, and proactively apply relevant innovations to ClickUp’s AI platform.Collaborate cross-functionally with teams to drive AI initiatives.

Quizlet, Inc. supports millions of learners each month by combining cognitive science with advanced machine learning. The platform serves two-thirds of U.S. high school students and half of college students, powering over 2 billion learning interactions monthly. Quizlet’s mission centers on making education more personal and effective for students, professionals, and lifelong learners. The AI & Data Platform team underpins Quizlet’s applied AI initiatives. This group develops and maintains the systems behind personalization, recommendations, the AI Coach, content generation, and emerging agentic experiences. The team oversees the full machine learning model lifecycle: data and feature engineering, training, evaluation, deployment, and inference. Reliability, speed, security, and observability guide their work. Their approach blends managed Google Cloud services, top vendor tools, open-source solutions, and custom internal abstractions to achieve efficient, reliable outcomes. Role overview The Senior Staff Engineer, AI Platform, is a senior individual contributor who defines the technical direction for Quizlet’s next generation of machine learning and large language model infrastructure. This hands-on role involves architecting core platform systems, steering build-versus-buy decisions, and collaborating with teams across Applied AI, Data Science, Product Engineering, and Infrastructure. The position sets standards for how models and LLM-driven systems are trained, evaluated, deployed, and governed at scale. This role is well suited to an engineer who excels at the senior-staff level in large organizations but values the autonomy and impact of a smaller, cloud-native setting. The technology stack includes Google Cloud, Kubernetes and GKE, distributed training, MLflow workflows, data and feature platforms, online and asynchronous inference, and the evaluation and observability tools needed to operate predictive ML and LLM systems at scale. Work location and schedule This is an onsite position based in San Francisco, CA. Team members are expected in the office at least three days a week: Monday, Wednesday, and Thursday, to foster collaboration.

Join Laurel as a Staff AI Platform Engineer, where you will be at the forefront of developing cutting-edge AI platforms that drive innovation and efficiency. In this role, you will collaborate with cross-functional teams to create scalable AI solutions that enhance our products and services.

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.

Role overview Harvey seeks a Staff Software Engineer to strengthen the AI Platform team in San Francisco. The position focuses on designing and building advanced software solutions that extend the platform’s AI features. Collaboration is central to this role. The engineer will work closely with colleagues across different teams to deliver systems that are both scalable and efficient. Every project supports Harvey’s broader mission and long-term goals. What you will do Design and implement software components that enhance AI capabilities Work with teams throughout the company to deliver reliable, high-performance systems Contribute to platform improvements that support Harvey’s mission Location This position is based in San Francisco.

About Quizlet:At Quizlet, we are dedicated to empowering learners to achieve their educational goals in the most effective and enjoyable manner. With our learning platform valued at over $1 billion, we cater to millions of students monthly, including a significant portion of U.S. high school and college students, facilitating over 2 billion learning interactions each month.By integrating cognitive science with cutting-edge machine learning techniques, we personalize and enhance the learning experience for students, professionals, and lifelong learners. Our enthusiasm lies in the potential to support more learners through diverse approaches and tools.Join Us in Shaping the Future of EducationBecome a part of our mission to design and deliver AI-driven learning solutions that extend globally and unlock human potential.About the Team:The AI & Data Platform team is committed to building and maintaining a robust, scalable, and efficient foundation for all data and machine learning operations at Quizlet. This team is the cornerstone of our AI aspirations. As we streamline our AI initiatives to create an integrated and powerful product suite, the platform team’s main focus is on operational excellence. We actively adopt and utilize top-tier MLOps and DataOps technologies to hasten innovation across Quizlet.About the Role:As a Staff AI & Data Platform Engineer, you will spearhead the design and development of Quizlet’s analytical data and machine learning infrastructure, ensuring our platforms are scalable, reliable, and geared for long-term success. You will collaborate closely with cross-functional teams to establish technical direction, guide architectural decisions, and mentor engineers across Data Science, ML Engineering, and Product.This position demands profound technical expertise, strategic insight, and the ability to deliver systems that enhance ML and data innovation at scale. You will gauge success through platform adoption, improvements in reliability, and outcomes related to developer productivity.We are pleased to inform you that this is an onsite position at our San Francisco office. To promote team collaboration, we ask employees to be present in the office at least three days a week: Monday, Wednesday, and Thursday, as well as as required by your manager or the company. We believe that this work environment enhances efficiency, fosters teamwork, and supports both personal and organizational growth.

Join David AI as a Staff Product EngineerAt David AI, we are pioneering the field of audio data research, applying a rigorous R&D methodology to create robust datasets that empower AI models. Our vision is to integrate AI seamlessly into daily life, with audio serving as the key medium. As the demand for high-quality training data grows, we position ourselves as the solution.Founded in 2024 by a team of seasoned engineers from Scale AI, we quickly garnered the trust of leading FAANG companies and AI labs. Our recent $50M Series B funding round was led by prestigious investors including Meritech and NVIDIA, underscoring our potential in the audio AI landscape.We pride ourselves on our dynamic, collaborative, and ambitious team, and we are on the lookout for exceptional talent in research, engineering, product, and operations to help us redefine audio AI.About Our Engineering TeamOur engineering team is at the forefront of innovation, building the infrastructure, platforms, and models that convert raw audio into valuable data for top-tier AI labs and enterprises. We are a close-knit group of product engineers, infrastructure experts, and machine learning specialists who are dedicated to establishing the first-ever audio data research organization.We operate with agility, taking ownership of our projects from inception to deployment, delivering production-ready solutions on a daily basis. Our engineers design real-time pipelines that manage vast amounts of speech data while deploying advanced generative audio models.Your RoleAs a Staff Product Engineer, you will spearhead our Product Engineering team, developing state-of-the-art products that enable our clients to harness audio data effectively for model training. You will collaborate with researchers to continually refine our data collection methodologies.Your ResponsibilitiesLead the development of full-stack features, rapidly iterating to deliver daily innovations to our users.Construct scalable systems that process terabytes of audio data and extract actionable insights.Deploy and assess LLM- and DSP-based solutions to enhance customer understanding of their data.Facilitate research iterations and deployment interfaces for data collection in collaboration with researchers and operations.

Airbnb, Inc. is looking for a Staff Platform Manager to lead AI Personalization for customer support in the United States. This position centers on developing and executing product strategy for the AI systems that help millions of guests and hosts receive support tailored to their needs. The AI Personalization team maintains the core systems that allow Airbnb’s support AI to understand context and respond with empathy, accuracy, and sound judgment. The goal: ensure every user receives support that feels as thoughtful and effective as Airbnb’s best human agents. Role overview The Staff Platform Manager oversees the full personalization stack, from retrieval systems to the AI interface. This role shapes product direction, drives adoption across Airbnb’s platforms, and champions a support experience that adapts to each guest and host. What you will do Define the long-term vision for personalized community support, ensuring AI understands and advocates for users as a skilled human would. Partner with data scientists, machine learning teams, and operations to identify and develop impactful personalization signals. Collaborate with ML engineers on contextual retrieval systems and prompt design for AI models. Create a multi-year product roadmap to advance AI support for the Airbnb community. Keep customer experience central in all aspects of platform design and delivery. Requirements Experience building or managing technical platforms, ideally in AI or personalization. Comfort working closely with engineering and data science teams on complex systems. Strategic mindset for long-term product planning and execution. Strong commitment to customer experience and delivering personalized interactions at scale.

Join Connectly as we revolutionize conversational commerce in Latin America, focusing on the WhatsApp platform. With WhatsApp shopping becoming increasingly prevalent, we are dedicated to creating an AI-driven sales solution tailored for large retailers. Our mission is to streamline the purchasing process by ensuring real human interaction in response to WhatsApp inquiries.As a VC-backed Series B startup, we boast a diverse and talented team hailing from industry giants like Meta, Google, and Uber. Operating in a hybrid work environment, we maintain offices in Bogotá and San Francisco, with teams distributed across Latin America, including Brazil, where many of our innovative AI initiatives are developed.

About AbridgeFounded in 2018, Abridge is dedicated to enhancing understanding in healthcare through our innovative AI-powered platform. We specialize in transforming medical conversations into structured clinical notes in real-time, enabling clinicians to prioritize patient care. Our enterprise-grade technology seamlessly integrates with electronic medical records (EMRs) to ensure accuracy and trust in AI-generated summaries.As pioneers in generative AI for healthcare, we are setting the industry benchmarks for responsible AI deployment across health systems. Our diverse team consists of practicing MDs, AI scientists, PhDs, creatives, technologists, and engineers united in their mission to empower patients and make healthcare more comprehensible. We have offices located in San Francisco's Mission District, New York's SoHo neighborhood, and East Liberty in Pittsburgh.The RoleJoin us as an AI Platform Engineer, where your work will significantly impact the healthcare sector. You will collaborate with a multidisciplinary team of researchers, clinical scientists, and product engineers to design and develop the runtime, orchestration engine, and evaluation platform necessary for agentic orchestration and LLM-driven workflows.What You’ll DoCreate GenAI systems that transform LLMs into composable, reliable tools, utilizing retrieval, tool use, agentic reasoning, and structured outputs.Develop a highly reliable and scalable agent runtime that includes orchestration, shared state and memory, tool-calling interfaces, and scheduling focused on cost, latency, and quality.Build secure, sandboxed environments for agent actions and code, optimizing for cold start, isolation, and observability.Deliver unified interfaces for multiple model sizes and providers; integrate with open tool ecosystems such as MCP-style connectors.Create an evaluation platform for both online and offline assessments, A/B testing, safety checks, and regression gates that enhance agent reliability over time.Collaborate with Research to bring new agent capabilities from prototype to production.What You’ll BringDemonstrated experience in building agent applications with tool-calling, context engineering, and related technologies.Strong problem-solving skills and the ability to work in a fast-paced, collaborative environment.Familiarity with generative AI technologies and their applications in healthcare.

About UsXOXO is an innovative research lab dedicated to crafting intelligent interfaces that enhance everyday life. Our stealth team, composed of passionate engineers, designers, and researchers, is focused on solving unique challenges that go beyond the workplace.With recent advancements in infrastructure, architecture, and model layers, we are actively seeking skilled builders to create the application layer that will actualize our visionary concepts.About the RoleWe are on the lookout for a proficient iOS engineer to lead the development of XOXO’s consumer app, featuring a pioneering interface for intelligence. This position calls for a robust engineer capable of managing the entire mobile surface area, from architecture and performance to refining a visually appealing design system that ensures intentional user interactions.A specific background is not mandatory; what truly matters is your passion for ownership: you take charge, work swiftly without compromising quality, and aspire to create a mobile product that redefines craftsmanship and performance standards.What You’ll DoDesign and launch the initial versions of our React Native app, transitioning it from concept to production.Convert a visually rich design system into reusable components, motions, and interaction patterns with seamless performance.Develop new product interfaces that seamlessly integrate modern AI/ML capabilities in a mobile-friendly manner.Enhance app performance, focusing on rendering, startup, memory consumption, battery usage, and perceived speed.Establish high standards for mobile engineering quality (including testing, monitoring, and release management) while collaborating with various teams to ensure successful delivery.

At Stuut AI, we are revolutionizing accounts receivable for B2B companies, enhancing collections to be smarter and more efficient. Our platform is increasingly being adopted by finance teams in various sectors, including industrials, chemicals, and manufacturing, with clients ranging from Fortune 10 enterprises to growing midmarket firms. Our innovative approach is supported by esteemed investors such as Andreessen Horowitz, Khosla Ventures, Activant, 1984 Ventures, and Page One.Position OverviewWe are seeking a dedicated Technical Staff Member focused on Internal AI Tooling. This pivotal role will involve constructing the foundational systems that allow Stuut to scale effectively. Your primary responsibility will be to design and implement internal infrastructures, automation, and AI-driven workflows to enhance operational efficiency across various departments, starting with marketing and extending to sales, operations, and product development.This is a significant role for a proactive individual who thrives on transforming manual or disjointed processes into scalable systems. Collaboration with leadership and cross-functional teams will be essential as you design AI agents, automation pipelines, and internal tools that streamline operations and unlock new capabilities.We are transitioning to an agent-first model, not only in our products but also in our operational approach. This role is central to that evolution.

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.

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 Databricks as a Staff Backend Software Engineer focusing on our cutting-edge AI Platform. In this pivotal role, you will be responsible for designing, developing, and optimizing backend systems that empower data scientists and engineers to build AI applications efficiently.As a key contributor, you will work closely with cross-functional teams to deliver scalable solutions that enhance our platform's capabilities. Your expertise will drive the development of robust features that support machine learning workflows and big data processing.

Join Databricks as a Staff Backend Software Engineer for our cutting-edge AI Platform. In this pivotal role, you will design and implement robust backend systems that power innovative AI solutions. Collaborate with a talented team to drive impactful projects and shape the future of data and AI.

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.

Role overview As a Product Engineer at liquid-ai, this position centers on shaping the company’s internal data and agent platform. The work involves designing, building, and launching solutions that reinforce the product lineup. Collaboration is key, with regular interaction across multiple teams. What you will do Partner with colleagues from various disciplines to define and deliver technical solutions Develop and maintain systems that support internal data and agent platform requirements Facilitate smooth integration between platforms and focus on optimizing system performance Location This role is based in San Francisco.