Backend Engineer at Kernel | San Francisco

Join Plaud as a Backend Engineer and be part of an innovative team driving the future of technology. You will design, develop, and maintain scalable backend systems that enhance our product offerings and improve user experiences. This is an exciting opportunity to work with cutting-edge technologies and collaborate with talented professionals in a fast-paced environment.

Join demo.levels.fyi, a trailblazing software company that empowers real-time collaboration on vital workflows. Established in 2012, we proudly serve over 10,000 clients globally and are backed by esteemed investors, including Example Capital. Having successfully raised our Series C, demo.levels.fyi is currently valued at $750 million.As a Backend Engineer, you will be an integral part of our dynamic team, directly reporting to the team manager. This pivotal role will enable you to influence various workflows and contribute to our innovative projects.

About CasaAt Casa, we believe that homes are among life’s most cherished assets, yet the experience of homeownership can often be frustrating. We are on a mission to revolutionize this experience by creating a next-generation personal property management solution tailored for single-family homes, ensuring that owning a home becomes a delight.Founded by early visionaries from Uber, CloudKitchens, and Levels, Casa is proud to be supported by a remarkable group of leading venture capital firms and angel investors. Our service is already live and delivering value to paying members.About the RoleWe are seeking a pioneering Senior Backend Engineer to join our dynamic team. In this role, you will be instrumental in designing, developing, and deploying robust backend systems that provide exceptional value to our members.You will collaborate closely with our founders, fellow engineers, and designers to craft innovative and impactful products. Your contributions will be vital in shaping our core systems and defining the culture of our founding team.Key ResponsibilitiesArchitect and develop scalable, secure, and reliable backend systems.Design and implement APIs that enhance our iOS applications and other client interfaces.Optimize the performance and scalability of our services to accommodate an expanding member base and increasing data volume.Stay updated with the latest advancements in backend technologies and cloud infrastructure, integrating new methodologies as suitable.Mentor a growing engineering team through code reviews and constructive feedback to uphold high-quality standards.About YouYou are passionate about building robust systems. You possess a deep understanding of backend architecture, API design, and database management, and are eager to construct systems that can scale with our increasing member base.You are excited to be a founding engineer at an early-stage startup, ready to contribute to the structure and systems being established, while also shaping the company culture.You thrive on building. You embrace the challenges and opportunities for growth that come with joining an early-stage company, and you excel in a fast-paced, evolving environment.You think and act decisively. Your proactive mindset will contribute significantly to our mission.

Join our innovative team at leverdemo193 as a Backend Engineer, where you will play a pivotal role in developing robust server-side applications. You will be responsible for managing data interchange between servers and users, focusing on the development of all server-side logic, maintaining the central database, and ensuring optimal performance and responsiveness to front-end requests. Collaboration is key, as you will also integrate front-end elements created by your colleagues into the application. A fundamental understanding of front-end technologies is beneficial for this role.

About the RoleJoin us as a pivotal technical founder at Known, where you will be responsible for developing the back-end systems and infrastructure that drive our innovative platform. Your expertise will shape the APIs that cater to millions of requests, establish real-time communication frameworks for voice and text interactions, and create data architectures that facilitate intelligent matching on a large scale. You will design robust, high-performance systems primed for growth alongside our expanding user base.In collaboration with our founding team, including specialists in AI/ML, full-stack development, product management, and design, you will architect back-end services that effectively manage complex workflows. This includes streaming LLM responses, processing payments, handling batch matching jobs, and enabling real-time chat functionalities, all while ensuring simplicity and enhancing developer efficiency. This is a high-responsibility position where your decisions will lay the groundwork for the future scalability of Known.ResponsibilitiesDesign and develop scalable back-end services using Node.js/TypeScript, including RESTful APIs, background job processing, and data pipelines for real-time and batch operations.Architect and enhance database systems with Postgres, focusing on schema design, query optimization, indexing strategies, and data integrity at scale.Build real-time communication infrastructures utilizing WebSockets for chat and WebRTC for audio/video, ensuring minimal latency and maximum reliability.Integrate and oversee third-party services (such as OpenAI/Anthropic LLMs, Google/Apple Pay, reservation platforms, and notification services) with effective error handling and monitoring.Collaborate with AI/ML engineers to construct APIs and data pipelines that support model predictions, manage training data collection, and facilitate experimentation workflows.Take charge of infrastructure, deployment, and observability — develop CI/CD pipelines, implement monitoring and alerting systems, optimize cloud expenses, and guarantee system reliability as user traffic increases.Design for performance and scalability — implement caching strategies, optimize API response times, and architect systems capable of accommodating significant growth without necessitating rewrites.Requirements4–6 years of experience in building production back-end systems, preferably for consumer products, high-traffic applications, or startups.Strong proficiency in TypeScript and Node.js, with a thorough understanding of asynchronous programming techniques.

Join Layerfi as a Backend EngineerAt Layerfi, we are revolutionizing the accounting landscape for small and medium-sized businesses (SMBs). With a decade of experience, we’ve established a powerful ecosystem of software tools that facilitate various business operations. However, the accounting sector has fallen behind, leaving SMBs to struggle with disjointed software and costly bookkeeping services.We are creating a cutting-edge accounting software that seamlessly integrates with the existing tools that SMBs rely on daily. Our platform empowers software companies to deliver modern accounting solutions and bookkeeping services to their clients, eliminating the need for outdated tools and expensive bookkeepers.Your RoleWe seek engineers who aspire to build not just products but also a strong team and company. This requires a blend of technical expertise across our tech stack along with unique skills such as:Forward-thinking coupled with a deep understanding of customer needs.A keen curiosity about technical and business challenges.Ability to navigate competing priorities while aligning with company objectives.A strong sense of ownership in product and team decisions.A passion for collaboration and enhancing the strengths of your colleagues.Our ideal candidates typically possess:A minimum of 2 years of experience in robust software development teams.Experience navigating the highs and lows of product development from inception to launch.A proven track record in team leadership and growth.We value proactive individuals who are eager to tackle challenges and seize opportunities, and we welcome those who reach out even if they don’t precisely meet the criteria.Our Technology StackWe do not focus on how familiar candidates are with our specific tech stack. One of the advantages of hiring exceptional engineers is our confidence in their ability to adapt and learn quickly, with support from the team. However, we do want all candidates to feel excited about the tools and environment they will engage with from day one.API language: KotlinEmbedded components: ...

Join Point as a founding Senior Backend Engineer and be part of a team creating a modern and aspirational banking experience. We are dedicated to enhancing everyday debit cards with exciting rewards and benefits, setting a new standard in banking.Discover more about Point's innovative team and dynamic culture here.

About UsAt Sierra, we are revolutionizing customer experiences by harnessing the power of AI. Based primarily in San Francisco, our vibrant team is expanding globally with offices in Atlanta, New York, London, France, Singapore, and Japan.Our culture is anchored in our core values: Trust, Customer Obsession, Craftsmanship, Intensity, and Family. These principles guide our actions and shape our work environment, ensuring that every team member feels valued and empowered.The visionary co-founders of Sierra, Bret Taylor and Clay Bavor, bring a wealth of experience from industry giants like OpenAI, Salesforce, Facebook, and Google, where they led groundbreaking projects and innovations.Your RoleJoin our dedicated engineering team of approximately 40 senior engineers, where you will collaborate in small, agile teams focused on solving customer challenges. As a Software Engineer for our Demo Platform, you will support our Sales Engineering and Go-To-Market teams, impacting every prospective client’s initial interaction with Sierra. Your responsibilities will include:Ownership of the Demo Platform: Design, develop, and maintain the systems that drive our demo environments, including multi-tenant mock organizations, seeded data, and configurations that ensure a seamless demo experience.Innovative Solutions: Collaborate with cross-functional teams to enhance and innovate features that make our demos reliable, efficient, and secure.

About UsScribe is a dynamic workplace where talented individuals come together to achieve remarkable professional milestones. With over 94% of the Fortune 500 relying on Scribe to enhance their operations, our Workflow AI platform effortlessly captures and optimizes workflows, enabling teams to work smarter, faster, and with greater consistency.Since our inception in 2019, we have experienced rapid growth, amassing more than 5 million users across 600,000 businesses. Headquartered in San Francisco, we have been recognized as a LinkedIn Top Startup, valued at over $1 billion, and supported by prominent investors. Join us as we transform the way work is accomplished.Our Work CultureWe are passionate builders striving to perfect our crafts. We deeply value our colleagues and are committed to achieving success together. We adhere to the following principles:Accelerate ImpactRaise the BarEmpower Our UsersClarity is KindRapid LearningOne Team, One DreamRole OverviewWe are on the lookout for a Senior Backend Engineer to become a vital member of our Core Engineering Team, which drives some of the key functionalities at Scribe, such as document viewing and editing, content embedding and exporting, and supporting essential integrations. Millions of users depend on these workflows daily.In this position, you will take the lead on influential projects — from enhancing critical document features to developing new greenfield systems — while collaborating across the technology stack to deliver exceptional product experiences. As a backend engineer, you will deepen our systems, engage in technical discussions, and elevate the standard of engineering excellence within the team.Your ResponsibilitiesDevelop and deploy backend features within our Django monolith, covering core document workflows (viewing, editing, embeds, exports) as well as innovative greenfield projects that broaden Scribe's capabilities.Enhance performance and reliability by fine-tuning database queries, endpoints, and caching layers for critical user workflows.Collaborate with product managers, designers, and frontend engineers to create intuitive and dependable experiences at scale.Contribute to the architecture and design of our systems to improve overall efficiency and maintainability.

Join us on-site in the vibrant Dogpatch neighborhood of San Francisco as a Senior Backend Engineer.About GigaGiga, a pioneering voice AI startup, has successfully secured a $61M Series A funding and boasts an impressive roster of clients including DoorDash. We are dedicated to revolutionizing the customer experience through real-time AI agents capable of understanding emotions and resolving issues instantly, while being scalable across the globe's largest enterprises.This is a pivotal moment for our company as we aim to expand our horizons. Our ambition is to position Giga as the premier AI platform for enterprise automation, driven by our cutting-edge voice superintelligence. To realize this vision, we are seeking exceptional engineers to join our team.Our engineers are empowered to make significant impacts, influencing the daily experiences of millions. This unique opportunity allows you to work alongside visionary founders, contribute to a commercially successful venture, and help shape a generational company. Here are some highlights about us:Voice AI startup Giga raises $61M Series ADoorDash and Giga PartnershipGiga is trusted by leading B2C companies around the world to manage their most complex support and operational workflows across various communication channels including voice, chat, and email. If this excites you, we encourage you to apply!The RoleWe are searching for innovative backend engineers to develop the infrastructure and systems that power our AI agents. You will engage with a variety of technologies from data pipelines and analytics to real-time agent systems, delivering features that have a direct impact on our customers' operations.This position grants you the freedom to own challenges from start to finish—identifying the optimal approach, constructing solutions, and refining them based on your findings.What You'll Work OnHere are a few key projects from our current roadmap:Analytics overhaul: Transitioning our analytics service to ClickHouse and optimizing it for the next phase of growth.Hallucination detection: Enhancing our detection systems with the aim of minimizing hallucination occurrences.Browser agent utilization: Scaling and stabilizing our systems to ensure robust performance.

About KreaAt Krea, we are at the forefront of developing innovative AI-driven creative tools designed to enhance artistic expression.Our commitment lies in making AI accessible and manageable for creative professionals. We aim to create tools that enhance human creativity rather than replace it.We view AI as a revolutionary medium that facilitates self-expression across diverse formats, including text, images, video, sound, and even 3D content. Our goal is to create smarter, more intuitive tools that effectively leverage this medium.Your RoleDesign, implement, deploy, and maintain robust private APIs for our core web and mobile applications.Create and optimize database models.Troubleshoot system issues, particularly those related to HTTP/3 and client-side connections.Enhance database and infrastructure performance through effective caching solutions and improved connection pooling.Analyze and identify bottlenecks in HTTP/WebSocket requests to facilitate real-time image and video generation.Advance observability, monitoring, and alerting capabilities for our services to ensure effective incident management.Scale our services through architectural advancements and infrastructure enhancements.Open-source significant innovations derived from our product development efforts.Refine software development processes to create web-native and AI-native creative tools.Elevate our product by incorporating enterprise-level features such as Audit Logs, SAML/SSO, and SCIM.Our Technology StackJavaScript/TypeScriptSvelte & SvelteKitNode.js, PostgreSQL, and RedisWebSocketsManaged Kubernetes clusters on AWSMonitoring via Axiom/HyperDX/Prometheus/OpenTelemetryCollaborative tools: GitHub, Slack, Notion

Think Different. Build the Future. Our MissionDevelop everyday AGI. Trustworthy, consumer-grade agents that redefine human–AI collaboration for millions. Software should proactively assist users, enhancing daily productivity and creativity.Why Join AGI, Inc.We are a pioneering team of elite founders and AI researchers with backgrounds from Stanford, OpenAI, and DeepMind. We are at the forefront of mobile and computer-use agents, focusing on bringing these groundbreaking capabilities to consumers on a large scale.With years of dedicated agent research, our AI is built around trustworthiness and reliability as foundational principles, rather than as afterthoughts.Backed by top-tier investors who have fueled the first generation of AI trailblazers, we are now on a mission to create the next: everyday AGI. (Watch the demo)If you envision possibilities where others see limitations, we invite you to read on.About the RoleAs one of the initial engineers, you will play a crucial role in shaping our core product and transforming how individuals incorporate AI companions into their daily workflows.Expect to:Innovate from scratch. Conceptualize on the whiteboard in the morning and have a demo ready by evening.Take ownership of the entire stack. Work across backend, frontend, model orchestration, and observability to minimize friction between ideas and final product delivery.Connect research with user satisfaction. Collaborate with scientists to translate breakthroughs into refined consumer experiences, pushing them to production within days, not months.Set the standard. Establish engineering, design, and reliability benchmarks that future team members will adhere to.Transform markets. Your features will not be confined to a sandbox; they will redefine how everyday individuals engage with and trust AI.You will lead projects from conceptualization to production deployment, iterating swiftly and placing genuine user feedback at the core of product decisions.Key ResponsibilitiesDevelop comprehensive experiences: Design, code, and implement end-to-end solutions that enhance user interaction with AI.

At Siftstack, we are revolutionizing the way advanced machines are constructed, tested, and managed. Our innovative platform provides engineers with real-time visibility into high-frequency telemetry, removing obstacles and facilitating quicker and more dependable development.Siftstack emerged from our extensive experience at SpaceX working on projects such as Dragon, Falcon, Starlink, and Starship, where the challenges of scaling telemetry, debugging flight systems, and ensuring mission reliability necessitated the creation of groundbreaking infrastructure. Founded by a team with backgrounds in SpaceX, Google, and Palantir, Siftstack is engineered for mission-critical systems where accuracy and scalability are essential.As a pivotal engineer focused on our data infrastructure, you will not only write code but also shape core architecture and contribute to scaling a real-time telemetry platform from the ground up. You will tackle intricate backend systems designed to capture, store, and serve millions of high-frequency data points per second, accelerating iteration cycles for some of the most advanced engineering teams globally.

Who We AreAt doss, we are pioneering the next generation of data management with our innovative AI-driven schema layer, designed specifically for physical-goods companies. Our platform acts as the 'Terraform for operators,' enabling businesses to adapt their systems of record swiftly in response to changes in their operations.Imagine leveraging AI foundation models for seamless schema migrations, achieving real-time observability across operational and financial data, and utilizing sophisticated git versioning for both schema and data modifications, all while composing workflows akin to infrastructure code.Your RoleDesign and develop the foundational EAV data model and schema-as-code platform that underpins every customer instance, ensuring a perfect balance between flexibility and transactional integrity.Construct a Git-style version control and migration engine capable of executing complex schema and data changes on live production environments for enterprise clients.Create AI-enhanced tooling that leverages foundation models to propose, validate, and implement new customer schemas and workflow definitions.Scale our white-labeled data warehouse (similar to BigQuery or Snowflake) to handle high-volume, low-latency analytics and automation tasks.Develop Terraform-like declarative APIs and SDKs to allow operations teams to manage business processes as code while ensuring security, tenancy, and performance.Provide end-to-end observability and searchable insights across supply chain, finance, and operational data, highlighting business logic in user-friendly language through AI-native search capabilities.Implement Enterprise guardrails within a composable system to preemptively identify anomalies or risky patterns.Foster a collaborative engineering culture, working closely with product and design teams to transform traditional back-office challenges into elegant, resilient systems that operators admire.Your SkillsProficiency in building large-scale ETL processes using databases such as Postgres, Elasticsearch, DuckDB, Memgraph (Graph DB), etc.Experience utilizing cloud services for the development and deployment of reliable web applications.Ability to work with abstractions to create scalable and complex graph-based architectures.About YouTeam-oriented: You bring enthusiasm, openness, and inquisitiveness to the team every day.Innovative thinker: You thrive on developing creative solutions to complex problems.Detail-oriented: You possess a keen eye for detail and a passion for delivering high-quality work.

About DelveDelve is pioneering an AI-native platform that revolutionizes compliance, transforming it from labor-intensive tasks into seamless, automated workflows.As the fastest growing compliance company in the industry, Delve enables hundreds of companies to save hundreds of hours (including notable clients like Lovable, 11x, and WisprFlow) by removing compliance busywork, allowing them to concentrate on what truly matters — securely serving their customers.Our team is a close-knit group of innovators—comprising former founders, operators, and engineers—dedicated to tackling genuine challenges for real customers. Our backgrounds span prestigious institutions like Stanford, MIT, Berkeley, and OpenAI, and we are funded by Insight Partners, General Catalyst, Y Combinator, among others. We recently secured a $32M Series A funding and are rapidly expanding!Step by step, we are on a mission to abolish busywork for humanity.About the RoleWe are seeking a Backend Engineer to take charge of the core systems that drive our AI workflows. In this role, you will design schemas, define APIs, and construct scalable backend architecture, closely collaborating with both engineering and product teams.This is an in-office position in San Francisco, where the founding team collaborates daily to make swift decisions and develop production-ready software deployed weekly.What You’ll DoManage backend systems: data models, APIs, and system design with scalability in mind.Lead schema and system design for our AI-native workflows.Utilize TypeScript, Node.js, Postgres (our current tech stack).Enhance backend performance and lay the groundwork for scalability.Collaborate closely with product engineers and AI engineers to define and implement backend contracts.Contribute to product development with practical engineering insights—this role is not just about fulfilling tickets.What We’re Looking For3–4 years of backend engineering experience (including personal projects and startup work).Strong experience in relational data modeling and API design.Proficiency in TypeScript, Node.js, Postgres, and ORM tools.Familiarity with system architecture patterns for scalable applications.Excellent problem-solving skills and a collaborative mindset.

Join Revi as a Senior Backend Engineer and Shape the Future of Retail! At Revi, we're revolutionizing the retail landscape by merging the physical and digital worlds. As pioneers in the emergence of Web 3.0, we are transforming brick-and-mortar experiences into seamless digital interactions. With over three decades of evolution in web technology, we are on the brink of a new era where physical stores can harness the power of the internet to create unparalleled customer experiences.Our mission is to empower businesses with a state-of-the-art in-store digital platform that fosters lasting customer relationships. Our beautifully designed self-ordering system enables consumers to buy, pay, and earn rewards effortlessly. With fresh Series A funding of $14.5 million from top-tier Silicon Valley investors, we are poised to seize a multi-billion dollar market opportunity.Why Join Us Now? This is a pivotal moment for Revi. With our AI-driven in-store platform already live with growing restaurant chains, we are experiencing strong product-market fit and customer demand for new features. This is your chance to make a significant impact on our technical direction while building on a foundation of proven success.

Senior Backend EngineerJoin LiteLLM, the leading AI Gateway trusted by industry giants including Adobe, Netflix, and NASA. Our platform empowers developers with secure and reliable access to Large Language Models (LLMs) and related services. We are currently seeking a dedicated Senior Backend Engineer to contribute to the development of robust guardrails and observability tools at scale.About The RoleIn this role, you'll take ownership of our guardrail and logging implementations. You will oversee backend code to ensure all guardrail interactions are logged accurately, user errors are communicated effectively, and that our observability tools function seamlessly under high traffic conditions. Your meticulous attention to detail regarding latency metrics, logging traceability, and backend guardrail registration will significantly bolster user confidence in our security and compliance capabilities.ResponsibilitiesDevelop and enhance our product to maximize performance, reliability, and ongoing improvements.Ensure guardrail and policy enforcement calls (e.g., applyguardrail) are accurately logged and traceable through our SpendLogs and relevant database tables.Design and implement CPU-level guardrails to mitigate common attacks on LLM APIs, MCP servers, and Agents.Identify and resolve silent failure points in guardrail creation, registration, and policy application—ensuring robust error handling and transparency for end users.Collaborate with observability tools such as Datadog, Splunk, Prometheus, and OpenTelemetry to maintain accurate, configurable, and effective monitoring and logging for backend systems.Enhance observability integrations to manage over 1 billion requests per month with minimal latency and no memory leaks due to Prometheus metrics cardinality.Work cross-functionally on backend engineering priorities including performance, reliability, and security enhancements.What We’re Looking ForBachelor’s or Master’s degree in Computer Science or a related field.4+ years of experience with Python and backend frameworks (e.g., FastAPI, Flask).Strong understanding of logging best practices, error handling, and secure backend development.Familiarity with monitoring, logging, or metrics tools.

About MetaviewAt Metaview, we are revolutionizing the workplace by eliminating the burdens of toil, the barrier to progress. We believe in the power of Human-Computer Symbiosis to enhance productivity.Our AI copilot transforms how hiring is approached, leading to:Increased flow-state, reduced toil.Enhanced insights, less guesswork.Focus on human-centricity over process-centricity.Founded in 2018 by Siadhal and Shahriar, both ex-Uber and Palantir employees, Metaview has grown to support thousands of users at leading companies like Quora, Robinhood, Brex, Elastic, and Replit. We're proud of our small yet high-performing team, dedicated to doing great work.About the RoleAs a Product Engineer at Metaview, you will embody a customer-centric and product-focused mindset. You will lead the design, development, and operational aspects of our products, taking ownership of your work in a collaborative and dynamic environment.While we seek a full stack talent, this role is geared toward those who lean towards backend development. Your primary responsibilities will revolve around backend coding, but you will also engage with other parts of the stack to maintain high productivity.We value clean and effective coding, and while familiarity with languages and tools is appreciated, a willingness to learn and adapt is essential as our product continually evolves. Currently, our technology stack includes:Python for backend application development.Typescript and React for frontend application development.Serverless Framework for application management.

About UsOur mission is to revolutionize language learning.Learning a new language can transform lives by providing access to diverse cultures, career opportunities, and communities. With two billion people globally striving to learn languages, the most effective method—one-on-one tutoring—remains difficult to access at scale and has not evolved significantly over the years. Speak is developing an AI-powered, human-like tutor that fits in your pocket, offering a conversation-first approach that allows learners to practice speaking, receive immediate feedback, and progress through thoughtfully designed lessons. This results in a comprehensive journey from novice to confident speaker across multiple languages.Since our launch in South Korea in 2019, Speak has emerged as the leading language learning app, now available to learners in various markets and over 15 languages. As one of the foremost AI companies globally, we have secured over $150 million in venture capital from notable investors such as OpenAI, Accel, Founders Fund, and Khosla Ventures, with a diverse team spread across San Francisco, Seoul, Tokyo, Taipei, and Ljubljana.About This RoleWe are seeking a Senior Backend Engineer, with full-stack capabilities, to help create innovative AI-driven product experiences. The ideal candidate should have experience collaborating closely with product, design, and machine learning teams, alongside a proven track record in developing polished consumer applications. This role is pivotal in shaping our latest products focused on programmatic, conversational language learning and will significantly impact the future direction of our company.Your ResponsibilitiesCrafting innovative AI-driven product experiences and user interfaces for the web.Full-stack engineering with a primary focus on designing scalable backend systems.Troubleshooting complex streaming challenges.Taking ownership of the complete development cycle of features from ideation to production.Writing code efficiently, shipping frequently, and making a substantial impact on our business by facilitating the scaling of our content.Your Profile5+ years of industry experience as a Backend Engineer, ideally within a fast-paced startup environment.Bonus: Experience on an app that has reached over 1 million users.Exceptional problem-solving and communication skills, along with the ability to work effectively in a collaborative environment.