Staff AI Engineer, Voice Agents

About Sage CareSage Care is a dynamic and rapidly expanding healthcare startup, founded by a team of visionary leaders from major tech companies like Apple, Uber, and Carbon Health, and supported by esteemed venture capital firms including General Catalyst and Chelsea Clinton. Our mission is to revolutionize healthcare by streamlining care navigation, making…

About Aqua VoiceAqua Voice is revolutionizing voice input for the AI era. We develop proprietary models and create deep operating system integrations, as mastering voice technology necessitates comprehensive control over the entire stack.The workplace landscape is evolving. Individual contributor roles are being replaced by the need to manage AI agents, and this transition is ideally suited for voice interaction.Unlike conventional conversational agents, we advocate for a voice-first approach where voice input leads to text output (VITO). We assert that voice interaction should transcend application layers, and our nimble organization is committed to pushing boundaries in this domain.Our relentless pursuit of excellence in this space has yielded promising results, and we invite you to be part of our journey.The RoleAs a Staff Engineer, you will take ownership of technical systems across the entire stack. Being a small, post-product-market-fit team, we are experiencing growth with real users facing real challenges.We favor modern technologies—opting for Bun over Node, Fly over AWS when applicable, and PyTorch over outdated ML frameworks.Your ResponsibilitiesGPU Inference: We independently run our Automatic Speech Recognition models.Real-time Transcription: Implementing WebSocket state machines, multi-provider failover, and achieving sub-100ms latency targets while tracking over 30 metrics per session.Native Applications: Utilizing Swift for macOS, C# for Windows, and Electron IPC for system-level programming.Backend Development: Employing Django for billing and analytics, Celery for background tasks, and PostgreSQL for database management.You will be involved in all aspects of our infrastructure and product development.Technology Stack- Languages: TypeScript, Python, Swift, C#- Runtime Environments: Bun, Node.js, Django, FastAPI- Machine Learning: PyTorch- Infrastructure: Fly.io, Terraform, AWS (RDS), Redis- Protocols: gRPC, WebSocket, RESTQualifications- Proven experience in building and managing systems at scale.- Strong architectural opinions that are adaptable.- Comfortable being the foremost technical expert in the room.- Capable of transforming ambiguous problems into functional systems.- Ability to write production-ready code.

Join Aircall as a Senior Software Engineer specializing in AI Voice Agents, where you'll play a pivotal role in designing and implementing innovative voice solutions. Your expertise in software development and artificial intelligence will help us enhance customer interactions through cutting-edge technology.

Join Deepgram, a pioneering leader in voice AI technology, as a Software Engineer specializing in Voice Agents for the restaurant industry. You will play a vital role in developing innovative AI applications that enhance customer experiences and streamline restaurant operations. Your expertise in software development and passion for AI will contribute to transforming how restaurants interact with their customers.

About Aqua VoiceAqua Voice is pioneering the voice input landscape for the AI era. By training our own models and creating deep OS integrations, we ensure that voice technology is executed flawlessly across the entire stack.The evolution of work is upon us; individual contributor roles are transforming as we now manage AI agents, a task that naturally aligns with voice interactions.We are not focused on traditional conversational agents; instead, we champion a voice-in-text-out (VITO) approach, believing that voice functionality should operate above traditional applications, and that innovative startups can lead in this domain.With an unwavering commitment to this vision, our progress has been promising, and we invite you to be a part of our journey.The RoleAs a growing team, you will have the opportunity to engage with all facets of our system.Recent projects include:Development of a real-time transcription server capable of managing thousands of concurrent audio streams.Training and deploying custom speech recognition models.Creating native integrations for macOS and Windows utilizing advanced system APIs.Technology StackFrontend: TypeScript, React, Next.js, ElectronBackend: Python, real-time server (Bun/Node.js), WebSocketsNative: Swift (macOS), C# (Windows)Machine Learning: Custom speech recognition models, inference pipelinesInfrastructure: Terraform, StripePrior experience with all these technologies is not required.Qualifications- Showcase your previous work and projects.- Adaptable in switching between programming languages and domains.- Capable of taking ownership of projects from concept to production.- Proficient in writing clean and maintainable code.- Experience with production systems is essential.- A positive attitude and a collaborative spirit are a must!

About Nooks.ai:Nooks is revolutionizing the sales landscape with our AI Sales Assistant Platform (ASAP), designed to eliminate mundane tasks and empower sales representatives to prioritize meaningful customer interactions. Our technology has enabled thousands of sales professionals to exceed their quotas, saved clients countless hours, and generated hundreds of millions of dollars in sales pipeline. Nooks is trusted by sales teams from leading companies such as Hubspot, Rippling, and Toast, as well as many others.As a high-performing team, we have successfully secured over $70M in funding from prestigious venture capital firms, including Kleiner Perkins, which marked its first investment in sales technology in over a decade by choosing Nooks. Over the last two years, we've achieved remarkable growth, quadrupling our annual recurring revenue (ARR) and then tripling it again, with plans to do so once more this year.To learn more about us, visit Nooks.ai. In this role, you will take ownership of our backend infrastructure for real-time audio and video calling (including Twilio, Salesfloor, A/V quality, recordings, and transcriptions), ensuring our dialer can scale reliably to handle 10x the current volume.Your Key Responsibilities:Architect and enhance our real-time voice infrastructure (WebRTC/SIP/Twilio).Guarantee that call quality and latency consistently meet SLA targets on a global scale.Develop services for advanced functionalities such as call transfers, monitoring, and recordings.Create observability and debugging tools to optimize call flows.Collaborate with Product and Support teams to implement new A/V features and ensure rapid issue resolution.Ideal Candidate Profile:6 to 10+ years of experience in backend or infrastructure engineering, particularly with real-time audio/video or telephony systems.Proven hands-on experience with technologies such as WebRTC, SIP, Twilio, or similar platforms.Strong understanding of distributed systems and low-latency infrastructure.Experience in debugging and optimizing Quality of Service (QoS) metrics including latency, jitter, and packet loss.At Nooks, our compensation package for eligible roles includes a base salary, equity options, and comprehensive benefits. The base salary is just one part of the total compensation, which may also encompass equity, health, dental, vision, life and disability insurance, hybrid work arrangements, and unlimited paid time off. Please note that benefits are subject to change and may vary based on the employment jurisdiction.

ABOUT THE ROLE:As an AI Engineer at Varick, you will take charge of designing and optimizing the intelligence layer within our enterprise operations. This involves creating agent systems that efficiently handle thousands of transactions, make classification decisions, and learn from human interactions.This position is suited for engineers with extensive experience in LLMs, agent architectures, and evaluation systems. You have successfully developed agent workflows that operate in production, not merely in demo environments. Your expertise includes prompt engineering, retrieval, tool calling, multi-agent orchestration, and the evaluation frameworks necessary for deploying trustworthy AI systems in enterprise settings.WHAT YOU'LL DO:• Design and implement agent architectures that tackle complex enterprise workflows, focusing on multi-step reasoning, tool calling, and exception handling.• Develop and sustain evaluation systems that ensure agent quality, accuracy, safety, and groundedness.• Create robust prompt systems, retrieval pipelines, and context engineering strategies to ensure reliable agent performance.• Establish feedback loops that empower agents to learn from human corrections and enhance their functionality over time.• Optimize inference costs and latency for production workloads to ensure efficiency.• Define and uphold best practices for agent reliability, observability, and governance.• Stay updated with the latest models, frameworks, and research to ensure impactful deployments into production.WHAT WE'RE LOOKING FOR:• At least 3 years of software engineering experience, with a minimum of 1–2 years dedicated to LLM applications or AI systems in a production environment.• Practical experience in constructing agent workflows featuring tool calling, retrieval, and multi-step reasoning.• A profound understanding of prompt engineering, context engineering, and methods to elicit reliable behavior from LLMs.• Experience in developing evaluation systems to assess AI output quality.• Proficient in Python with a solid foundation in backend engineering principles.• You have delivered AI features to actual users and have navigated challenges such as hallucinations, edge cases, accuracy drops, and cost management.• Must be based in San Francisco.

Join Varick Agents as a Staff Engineer, where you will play a crucial role in developing innovative solutions that drive our company's success. We are looking for a highly skilled engineer who is passionate about technology and eager to tackle complex challenges. You will work closely with cross-functional teams to design, implement, and maintain software systems that enhance our operational efficiency and customer satisfaction.

About Aqua VoiceAqua Voice is pioneering the voice input technology for the AI era. Our unique approach involves training proprietary models and establishing deep integrations with operating systems, ensuring optimal voice interaction capabilities.The landscape of work is evolving; the traditional role of an individual contributor is being replaced by the management of AI agents, making voice interaction a natural fit for this new paradigm.Rather than developing mere conversational agents, we envision a more intuitive method of computer interaction—voice input leading to text output (VITO). We assert that voice technology should operate at a foundational level, allowing a small, agile company like ours to innovate and excel.We are passionately committed to this mission, and our initial results have been promising. Join us in shaping the future!The OpportunityWe are looking for an iOS Engineer to help us build Aqua Voice from the ground up. This greenfield project offers you the chance to shape the mobile experience entirely.Your Contributions Will Include:Developing a native iOS application with system-level voice input features (including keyboard extensions, Shortcuts, and Siri integration).Implementing real-time audio capture and streaming to our transcription backend.Creating deep iOS integrations to enhance user experience.This role requires a focus on native performance and comprehensive system integration—this is not just a web view wrapper.Technology StackSwift (SwiftUI + UIKit where applicable)Audio Technologies: AVFoundation, Audio Unit, real-time streamingNetworking: WebSockets, streaming protocolsSystem Integrations: Keyboard extensions, Shortcuts, accessibility APIs

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.

Join Collective Health as a Staff AI Engineer, specializing in Agentic AI and Automation. In this pivotal role, you will lead innovative projects that leverage artificial intelligence to enhance health management solutions. Collaborate with cross-functional teams to design and implement cutting-edge AI systems, ensuring they align with organizational goals and deliver tangible results.

Merge stands at the forefront of providing innovative agentic tools and customer-facing integrations for leading LLMs, Fortune 500 companies, and B2B SaaS enterprises. Our powerful platform features two flagship products: Merge Unified, which allows businesses to seamlessly integrate hundreds of tools through a single API, and Merge Agent Handler, which equips AI agents with secure access to a multitude of third-party services. Trusted by thousands, Merge's enterprise-grade platform manages the entire integration lifecycle—from authentication and security to monitoring and maintenance—helping organizations accelerate product development, enhance sales, reduce churn, and conserve engineering resources, enabling them to concentrate on their core offerings. Who We Seek:We are on the lookout for a passionate Senior/Staff Engineer, Agent Handler to help shape the next generation of Merge through innovative, AI-native products powered by large language models. You will be responsible for overseeing foundational systems that facilitate AI-driven capabilities and operational efficiencies across the organization. As a leader, you will guide a high-impact team through dynamic problem spaces, collaborating closely with product, design, and go-to-market teams to transform cutting-edge AI technology into tangible customer and business value.Your Responsibilities:Champion a culture of innovation, experimentation, and technical excellence.Develop and implement the roadmap for AI-driven products and internal tools to enhance integration development, monitoring, and automation.Work in tandem with product, design, and engineering teams to create intelligent, user-focused tools that set Merge’s platform apart.Ensure that AI models and systems are deployed with a strong emphasis on scalability, performance, and security.

Join Our TeamAqua Voice is pioneering the voice interaction layer for the AI-driven era. We develop our own models and create deep OS integrations, as mastering voice technology necessitates control over the entire stack.The landscape of work is evolving rapidly. It's no longer just about individual contributions; now, you manage AI agents, and voice interaction is ideally suited for this new paradigm.We are not in the business of crafting conversational agents. Our vision is that the most intuitive way to engage with your computer is through voice commands with text responses (VITO). We believe that voice technology should operate at a layer above applications, and as a small company, we have the potential to push boundaries in this area.With relentless dedication, we are making great strides, and we invite you to be part of this journey.Your RoleWe are seeking a talented designer who is also proficient in coding.You will take the reins on design for our desktop applications, web platforms, and marketing collateral. You will implement your designs using React, TypeScript, and CSS.This is primarily a design-focused position. We prioritize your aesthetic sense over the speed of engineering.

Baseten creates AI inference solutions for clients such as Cursor, Notion, OpenEvidence, Abridge, Clay, Gamma, and Writer. The team blends AI research, infrastructure, and developer tools to help organizations deploy advanced models. Backed by $300M in Series E funding from BOND, IVP, Spark Capital, Greylock, and Conviction, Baseten is expanding quickly and shaping the landscape for engineers building AI products. Role overview The Software Engineer - Voice AI role centers on building and deploying open-source voice models for real-world use. Voice is becoming a key interface across the web, and this position addresses the technical challenges of bringing production-ready Voice AI to market. The work supports applications in productivity, customer service, clinical dialogue, creator tools, education, and more, helping to change how people interact with technology across sectors. This engineer leads Baseten’s Voice AI efforts, guiding the proprietary inference stack that powers Voice AI models. The role balances shaping the product roadmap with hands-on engineering. Collaboration is a core part of the job, working closely with Forward Deployed Engineers, Model Performance Engineers, and other technical teams to advance Voice AI capabilities. Sample projects and initiatives The world's fastest Whisper, with streaming and diarization Canopy Labs selects Baseten for Orpheus TTS inference Partnering with the Core Product team to build an orchestration framework for a multi-model voice agent Working with the Training Platform team to support ongoing training of voice models Designing a developer-friendly API and SDK to encourage self-service adoption of Baseten Voice AI products Location San Francisco

About DecagonDecagon stands at the forefront of conversational AI technology, empowering brands to offer exceptional concierge-style customer experiences. Our innovative platform is trusted by industry leaders such as Avis Budget Group, Block’s Cash App and Square, Chime, Oura Health, and Hunter Douglas, enabling them to deploy AI agents that facilitate personalized and engaging interactions across various channels including voice, chat, email, and SMS.We envision a future where customer interactions are transformed from mundane support tickets and waiting on hold to swift resolutions, meaningful dialogues, and enriched relationships. Our commitment to this vision is supported by esteemed investors like a16z, Accel, Bain Capital Ventures, Coatue, and Index Ventures, among others.Based in San Francisco, we foster an in-office culture that prioritizes excellence and momentum. Our core values—Just Get It Done, Invent What Customers Want, Winner’s Mindset, and The Polymath Principle—guide our collaborative efforts and collective growth.About the TeamThe Agent Orchestration team is responsible for developing the fundamental execution layer that facilitates every agent interaction. Our systems are designed to orchestrate model reasoning, assess agent performance, and ensure consistent agent behavior in real-world customer scenarios.With a focus on accuracy, dependability, and speed, our work influences how Decagon agents strategize, decide, and implement actions during millions of interactions.About the RoleAs a Senior Software Engineer on the Agent Orchestration team, you will be pivotal in shaping the long-term architecture of Decagon’s agent platform. You will spearhead substantial, multi-quarter projects that define the functionality and scalability of our orchestration engine, enabling engineers across the organization to build effectively upon it.This position is ideal for individuals who excel in technical depth, possess the ability to influence cross-functional teams, and are passionate about developing robust, principled systems that endure. You will collaborate closely with teams in Research, Infrastructure, Product Engineering, and Agent Software Engineering to establish the standards and frameworks that uphold the reliability and intelligence of Decagon agents.In this role, you will:Take ownership of the architecture and ongoing evolution of Decagon's core execution engine for agents.Lead the design of systems that manage complex reasoning and action flows on a large scale.Enhance reliability, testing, and observability standards throughout the orchestration stack.

About UsAt Sierra, we are pioneering a transformative platform designed to empower businesses in crafting exceptional, human-centric customer experiences through AI technology. Our primary operations are situated in San Francisco, with expanding offices located in Atlanta, New York, London, France, Singapore, and Japan.Our corporate culture is deeply rooted in five core values: Trust, Customer Obsession, Craftsmanship, Intensity, and Family. These guiding principles shape our actions and define the essence of our work.Our co-founders, Bret Taylor and Clay Bavor, bring a wealth of experience from notable tech giants. Bret, currently the Board Chair of OpenAI, has previously served as co-CEO of Salesforce and was a key figure at Facebook. Clay led Google Labs and spearheaded transformative AR/VR initiatives during his extensive tenure at Google.Your RoleAs a Multilingual Agent Experience Designer, you will be instrumental in enhancing and scaling high-quality voice experiences across our global portfolio of AI agents. You will collaborate with cross-functional teams and customer stakeholders to integrate systems thinking, design judgment, and operational excellence, driving improvements in voice quality and facilitating multilingual readiness for more human-like interactions.Enhance the breadth and depth of voice quality: Assess and iterate on voices from various providers across multiple languages and use cases, ensuring clarity, naturalness, and appropriateness in every interaction while continually refining products and systems.Accelerate multilingual readiness and launches: Collaborate with product, engineering, and deployment teams to explore solutions, evaluate options, mitigate risks, and inform voice-related decisions that ensure timely and high-confidence launches across different regions.Establish and implement effective evaluation methods: Develop structured processes for assessing voice performance and interaction quality to help teams make informed decisions and identify issues early on.Collaborate cross-functionally to address voice and interaction challenges: Work alongside engineering, product, and support teams to analyze quality gaps, diagnose root causes, and drive necessary improvements.

About UsZeta Global (NYSE: ZETA) is an innovative AI-driven Marketing Cloud that harnesses cutting-edge artificial intelligence (AI) and an immense array of consumer signals to streamline the process for marketers in acquiring, nurturing, and retaining customers more effectively. Our Zeta Marketing Platform (ZMP) aims to simplify complex marketing strategies by integrating identity, intelligence, and omnichannel activation into a unified platform—powered by one of the industry's largest proprietary databases and AI. Our enterprise clientele, spanning various sectors, can tailor consumer interactions on an individual basis across all channels, resulting in superior marketing outcomes. Founded in 2007 by David A. Steinberg and John Sculley, Zeta is headquartered in New York City with global offices. Discover more at www.zetaglobal.com.Role OverviewWe are seeking a proactive and skilled Agentic AI Engineer to develop bidder-adjacent agents that enhance campaign performance through RAG and tool-using workflows within a closed-loop ACE (Observe → Reason → Act → Evaluate) framework. This role transcends traditional linear model training and deployment, focusing instead on agentic decision-making, evaluation, and safety in a fast-paced AdTech environment.

About Scale AI At Scale AI, we are dedicated to propelling the advancement of AI applications. Over the past eight years, we have established ourselves as the premier AI data foundry, supporting groundbreaking innovations in fields such as generative AI, defense technologies, and autonomous vehicles. Following our recent Series F funding round, we are intensifying our efforts to harness frontier data, paving the way toward achieving Artificial General Intelligence (AGI). Our work with enterprise clients and governments has enhanced our model evaluation capabilities, allowing us to expand our offerings for both public and private evaluations. About the ACE Team The Agent Capabilities & Environments (ACE) team, a vital part of Scale’s Research organization, unites customer-focused Researchers and Applied AI Engineers. Our primary mission is to conduct research on agent environments and reinforcement learning reward signals, benchmark autonomous agent performance in real-world contexts, and develop robust data programs aimed at enhancing the capabilities of Large Language Models (LLMs). We are committed to creating foundational tools and frameworks for evaluating models as agents, focusing on autonomous agents that interact dynamically with a wide range of external environments, including code repositories and GUI interfaces. About This Role This position sits at the cutting edge of AI research and its practical applications, concentrating on the data types necessary for the development of state-of-the-art agents, including browser and software engineering agents. The ideal candidate will investigate the data landscape required to propel intelligent and adaptable AI agents, steering the data strategy at Scale to foster innovation. This role demands not only expertise in LLM agents and planning algorithms but also creative problem-solving skills to tackle novel challenges pertaining to data, interaction, and evaluation. You will contribute to influential research publications on agents, collaborate with customer researchers, and partner with the engineering team to transform these advancements into scalable real-world solutions.

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 Aqua VoiceAqua Voice is pioneering the voice input layer for the AI era. We develop our proprietary models and create deep operating system integrations, as mastering voice interaction necessitates comprehensive control over the entire technology stack.The landscape of work is evolving. Individual contributor roles have transformed; now you will manage AI agents, a task that is ideally suited for voice technology.We are not in the business of creating simple conversational agents. Our vision is that the most intuitive interaction with computers is through voice input with text output (VITO). We advocate for voice integration at a fundamental level, confident that a nimble company can lead innovation in this space.Our commitment to this vision is unwavering, and we have already made significant strides. We invite you to become a part of this exciting journey.The OpportunityAs we witness growing enterprise interest—teams eager to integrate Aqua into their workflows—you will lead these initiatives.Full-Cycle Sales Ownership: From initial conversation to contract signing, you will manage the entire sales process without handoffs.Land and Expand Strategy: Begin with key champions within organizations, and grow our presence across entire teams.Navigating Enterprise Processes: You will adeptly handle security reviews, procurement, and legal considerations, drawing on your previous experience.Defining Sales Methodology: As a key early-stage hire, you will help shape how enterprise sales are conducted at Aqua Voice.Collaboration with Product Teams: Your insights into enterprise needs will directly influence our product roadmap.