Backend Software Engineer at Collate | San Francisco

About CollateCollate is a cutting-edge AI-driven document generation platform specifically designed for the life sciences sector. Our mission is to streamline documentation processes through automation, enabling our clients to accelerate the delivery of life-saving innovations to patients significantly faster. As a comprehensive solution, Collate supports every phase of drug, diagnostic, and medical device development, from initial concept to market launch.Founded by CEO Surbhi Sarna, a former General Partner at Y Combinator, Collate benefits from her extensive experience, including the founding of nVision Medical which pioneered a novel ovarian cancer detection method that was later acquired by Boston Scientific. Our CTO Nate Smith, previously a Visiting Partner at Y Combinator, is also the founder of Lever. Our talented team of AI researchers, engineers, and designers hail from prestigious companies such as Google, Nvidia, Meta, Netflix, Amazon, AirBnB, Hippocratic AI, and Grail, with 40% of our members being former startup founders.As a compact yet highly skilled team, we have secured over $30 million in seed funding from premier investors including Redpoint, First Round Capital, Conviction, and Y Combinator, as well as leaders in the healthcare and AI sectors. This represents a unique opportunity to join a pioneering company with the potential for transformative impact, led by experienced founders equipped with the resources necessary for large-scale execution.About the RoleWe are seeking a Full-Stack Software Engineer (Backend-Leaning) to architect and develop the systems and user-focused features that drive Collate's success. Your primary responsibilities will revolve around backend challenges—such as APIs, services, and infrastructure—while also engaging in the delivery of complete end-to-end features.This role offers a chance to help shape our technical framework, work closely with design and product teams, and influence the user experience of Collate from the very beginning.Modern Tech StackCollate employs a modern technology stack to ensure a highly reliable and available platform. We utilize Go for scalable backend services, TypeScript and React for frontend development, and Python for AI and ML services. Our infrastructure leverages AWS with Kubernetes for orchestration and Terraform alongside Argo CD for configuration management. Key systems in our architecture include S3, PostgreSQL, Kafka, OpenSearch, LLMs, and various AI models.

About CollateCollate is an innovative AI-driven document generation platform tailored for the life sciences sector. Our mission is to streamline paperwork through advanced AI technology, enabling our clients to deliver life-saving innovations to patients significantly faster. Serving as a comprehensive solution, Collate enhances every phase of drug, diagnostic, and medical device development—from initial concept to market readiness.Under the leadership of our CEO Surbhi Sarna, a distinguished former General Partner at Y Combinator, and our CTO Nate Smith, a former Visiting Partner at Y Combinator, our team comprises AI researchers, engineers, and designers with experience from top-tier companies like Google, Nvidia, Meta, and Netflix. Impressively, 40% of our team are former founders themselves.We are a compact, elite team backed by over $30 million in seed funding from renowned investors including Redpoint, First Round Capital, Conviction, and Y Combinator, along with industry leaders in healthcare and AI. This is a unique opportunity to become part of a groundbreaking company poised to make a significant impact, guided by experienced founders with the resources to scale effectively.About the RoleWe are seeking a passionate AI Engineer to assist in developing and operationalizing the models and systems that drive Collate's innovative products. Your role will bridge the realms of machine learning, software engineering, and product development—transforming pioneering research into dependable, user-centric functionalities.This position offers a remarkable chance to influence the application of advanced AI in the life sciences sector, where performance, safety, and trust are as crucial as innovation. As one of the initial AI-focused engineers at Collate, you will help establish standards for evaluating and deploying models that have a direct impact on drug and medical device development.

Join Collate as a Frontend Software EngineerAt Collate, we are revolutionizing the life sciences sector with our innovative AI document generation platform. Our mission is to expedite the delivery of life-saving innovations to patients by automating complex paperwork. As a seamless end-to-end solution, we support every stage of drug, diagnostic, and medical device development, from initial concept to market launch.Led by our visionary CEO, Surbhi Sarna, a former General Partner at Y Combinator, and our CTO, Nate Smith, a former Visiting Partner at Y Combinator, we have assembled a team of elite professionals with experience from top-tier companies like Google and Amazon. Our small team has garnered over $30M in seed funding from esteemed investors including Redpoint and First Round Capital, positioning us for rapid growth and impact in the healthcare field.As a Frontend Software Engineer, you will play a pivotal role in shaping the user experience at Collate. Your innovative contributions will translate complex AI technology into intuitive and user-friendly tools for doctors, patients, and researchers. Your work will directly influence the product experiences that are critical for improving patient outcomes.You will be working on a predominantly frontend-focused enterprise workflow application, ensuring the interface is clear, reliable, and trustworthy. This is a unique opportunity to design the intersection where transformative technology meets real-world users.Our Cutting-Edge Tech StackWe utilize modern technologies including TypeScript, React, and Tailwind CSS for our frontend development, creating a dynamic environment for innovation and collaboration.

Join our dynamic team at collate as a UI Designer, where your creativity and innovative design skills will help shape intuitive user experiences. Collaborate with cross-functional teams to craft visually stunning interfaces that engage and delight users.

Join Condor Software as a Full-Stack Platform EngineerAt Condor, we are revolutionizing the financial infrastructure that supports clinical development. With billions invested annually in discovering and developing new therapies, we strive to connect clinical operations and finance into a cohesive system. By integrating real-time financial intelligence, we empower R&D and finance leaders with the tools they need to make informed, high-stakes decisions.We are an AI-driven, pharma-native infrastructure provider, scaling industry standards in collaboration with top-tier partners. Our platform facilitates prediction, control, and execution in the most complex R&D environments worldwide.The Importance of Your RoleHaving established ourselves as a trusted partner for enterprise teams, we are now focused on the challenging task of scaling our platform to meet increasing demands. As a rapidly growing company, backed by prominent investors like Felicis and 645 Ventures, this is a unique opportunity to contribute to the foundational infrastructure that will redefine how therapies reach patients.Your ResponsibilitiesAs a Full-Stack Platform Engineer, you will be pivotal in building and scaling the core platform that supports the financial intelligence infrastructure relied upon by leading biopharma companies. This role encompasses critical engineering tasks at the intersection of backend systems, cloud infrastructure, and intelligent automation, with a strong emphasis on reliability and scalability.Your primary focus will be on backend architecture, where you'll design and implement services that drive complex financial and operational workflows. You'll be instrumental in shaping data flow, workflow orchestration, and enabling emerging AI-driven capabilities. This role goes beyond simple integration; you'll be crafting robust primitives that support other teams as our product and customer base expand.Working as a core member of a cross-functional product team, you will closely collaborate with product managers, designers, quality engineers, and data specialists to transition features from concept to production. While backend expertise is crucial, you will also engage across the stack to ensure the platform's capabilities are effectively leveraged.

Join our innovative team at arine as a Full Stack Software Engineer, where you'll have the opportunity to work on cutting-edge technologies and create impactful solutions. As a vital part of our software development team, you will collaborate with cross-functional teams to design, develop, and maintain web applications that provide exceptional user experiences.

About HappyRobotHappyRobot is pioneering the AI-native operating system for the real economy—an innovative platform that seamlessly integrates intelligence with actionable outcomes. By harnessing real-time insights, specialized AI agents, and a coordinating intelligence, we empower enterprises to manage intricate, mission-critical operations with genuine autonomy.Our AI OS continuously accumulates knowledge, optimizes processes at every level, and adapts over time. We're initially focusing on supply chain and large-scale industrial operations, where resilience, speed, and ongoing enhancement are paramount—liberating humans to concentrate on strategic thinking, creativity, and other high-value pursuits.Discover more about our vision in our Manifesto. HappyRobot has successfully secured $62M in funding to date, including a recent $44M Series B round in September 2025. Our esteemed investors include Y Combinator (YC), Andreessen Horowitz (a16z), and Base10, who share our commitment to transforming enterprise operations. We are channeling this investment into assembling a world-class team—individuals with unwavering determination, exceptional problem-solving abilities, and a passion for pushing boundaries in a dynamic, high-pressure environment. If this resonates with you, we invite you to join us at HappyRobot.About The RoleAt HappyRobot, Full Stack Engineers take charge of significant components of the product and infrastructure from start to finish.We are seeking creators who thrive in uncertain environments, have a profound appreciation for their craft, and desire authentic ownership over their creations.

About Tacit Tacit is an early-stage deep tech startup based in San Francisco, focused on hardware that changes how people interact with computers. Backed by General Catalyst, Khosla Ventures, and Greylock Partners, the team brings experience from Stanford, BrainGate, Oculus, and Tesla. The company is committed to solving complex engineering problems to deliver new products that push the boundaries of human-computer interaction. Role Overview The Full-Stack Software Engineer will help turn ambitious ideas into real products, working across Tacit's software stack. This role involves taking features from initial concept through to deployment and shaping user experiences that support the company’s mission. What You Will Do Develop the internal product stack to improve workflows and prototypes across devices and companion clients. Build and expand internal applications for demos and data collection, supporting idea testing and user experience validation. Prototype new features for human-computer interaction, iterate with test users, and refine until the experience feels seamless. Design and run product experiments, including A/B tests and feedback loops, to quickly gather insights and guide product direction. Streamline data collection and participant experiences, including setup flows, session reliability, metadata capture, monitoring, and labeling. Develop demo features that showcase real-time sensing and inference in engaging, reliable ways. Find and implement integrations that improve team workflows and efficiency. Create and improve automated testing and release systems, such as CI/CD pipelines, smoke tests, and regression checks, to support frequent updates. Work closely with machine learning, hardware, and industrial design teams to define requirements, deliver results, troubleshoot, optimize, and ensure reliability. Qualifications Strong skills in Python (FastAPI, Pydantic; experience with pandas or numpy) and modern TypeScript/React. Experience building production backends (APIs, data models, reliability, observability) and delivering features for end users. History of shipping multiple products from start to finish.

At Siftstack, we are revolutionizing the development, testing, and operation of modern machines. Our innovative platform empowers engineers with real-time observability over high-frequency telemetry, effectively eliminating bottlenecks and facilitating faster, more dependable development.Founded by a team of experts from SpaceX, Google, and Palantir, Siftstack was inspired by our experience with pioneering projects like Dragon, Falcon, Starlink, and Starship. Our mission-critical infrastructure is designed for precision and scalability, meeting the highest demands of reliability in engineering.As an early-stage engineer at Siftstack, you will not only write code, but you will also play a pivotal role in defining our architecture, shaping our product, and cultivating a culture focused on addressing real engineering challenges. If you thrive on tackling complex technical problems and want to build foundational systems that support intricate machines, we'd love to hear from you.

About StackAIStackAI is a revolutionary no-code AI workflow platform that enables businesses to construct, implement, and expand AI-driven workflows without requiring extensive machine learning expertise. With a growing user base and increasing enterprise adoption, our goal is to democratize access to large language models (LLMs), empowering every business operator—beyond just developers. Supported by Y Combinator and top-tier investors, we are laying the groundwork for the AI-driven future of work.The RoleAs a Senior Full Stack Engineer, you will be instrumental in defining the product and technical architecture at StackAI. Your responsibilities will span the entire technology stack, from crafting scalable backend systems to creating stunning and user-friendly frontend interfaces, and incorporating advanced AI models into our platform. This role offers significant impact, as you will work closely with the founding team, take charge of essential product features, and shape the engineering culture of a rapidly evolving startup.We seek exceptional 10X engineers—innovative builders who can consistently deliver results in a dynamic environment, remain inquisitive, and excel in diverse roles.ResponsibilitiesIn this role, you will:Build and own the entire platform, from backend services and APIs to frontend interfaces.Create robust, scalable backend systems utilizing Python and FastAPI (or similar), with optimized databases (SQL/NoSQL).Design and maintain high-quality user interfaces using React, Next.js, TypeScript, and Tailwind CSS, ensuring polished, intuitive, and responsive user experiences.Integrate new AI models and features into our products for seamless performance and enhanced value.Manage StackAI’s landing and product pages to establish benchmarks for clarity, design, and quality.Collaborate across the stack to connect backend services with frontend applications seamlessly.Engage with design, product, and customers to refine product direction and prioritize user needs.Stay at the forefront of full-stack technologies, promoting best practices and innovative solutions.Assist with customer support as needed; every team member contributes to user satisfaction.

About SvixSvix is an innovative startup revolutionizing server-to-server communication with a focus on webhooks. Our robust, scalable infrastructure is trusted by industry leaders such as Etsy, TaskRabbit, and Brex, including Fortune 500 companies.With a product and team in the top 1%, we take pride in our customer satisfaction and aim to create a next-generation developer infrastructure company.To fuel our growth, we've successfully raised $11 million from prestigious investors like a16z and Y Combinator, as well as influential founders and CTOs from GitHub, Segment, Lookout, and Fly.io.About the RoleWe are in search of an exceptional full-stack engineer who is passionate about creating reliable and user-centric products. In this role, you'll tackle engaging problems and technical hurdles. Our fast-paced environment values quick execution, and you will share our commitment to delivering an outstanding developer experience.If you are a high achiever eager to excel in your career alongside like-minded individuals, this is the perfect opportunity for you.MissionWe seek a versatile engineer capable of contributing to both frontend and backend development to enhance user experiences and build scalable infrastructure. You will face intriguing challenges in a dynamic setting where speed of execution is paramount, and we are dedicated to ensuring a remarkable developer experience.OutcomesDeliver high-quality production code in a high-energy environment.Assist the team in scaling the product while maintaining stability and uptime.Develop new features that enhance the developer experience for our clients.CompetenciesA talented and enthusiastic engineer committed to delivering excellence.Proficiency in crafting production-ready UIs using React and TypeScript.Experience in developing backend services with strongly typed programming languages.A solid understanding of design principles and user experience best practices.Exceptional communication skills and a collaborative spirit.A passion for ensuring a fantastic developer experience.

Why Choose Alex?At Alex, one of the most promising startups emerging from our Y Combinator batch, we are making significant strides in the hiring landscape. We have secured strong funding, are generating revenue, and have ample runway to fuel our growth.Our innovative AI-driven recruitment tool revolutionizes the job interview process, enabling companies to obtain critical hiring insights more swiftly and effectively than ever. Our clients are enthusiastic about our product, and we are just beginning our journey.Who We Are?We are a team of individuals who:Thrive on tackling complex engineering challengesAdapt quickly and are committed to achieving resultsDedicate ourselves to hard workAct with urgencyValue in-person collaboration in our San Francisco office, five days a weekTechnologies We UtilizeWe prefer candidates with experience in:JavaScript (Typescript, React, Node, Next)PythonCloud and DevOps tools (Azure, Kubernetes, Docker)System ArchitectureYour ResponsibilitiesAt Alex, we operate similarly to a marketplace, providing unique interview experiences for candidates and a robust data analysis platform for employers. As a hands-on engineer, you will develop both consumer-facing applications and enterprise-grade software, with ample opportunities for professional growth. Potential consumer software challenges include:How can we reduce average interviewer response latency to 200ms?How can we refine our models to minimize hallucinations and help Alex pass the Turing test?How will our system architecture evolve as we scale to accommodate thousands of users concurrently?You will also address enterprise-related software challenges such as:How do we integrate with our clients' internal hiring systems?What is the optimal way to visually present interview results swiftly?How can Alex facilitate end-to-end coordination of the hiring process?And a myriad of feature requests awaiting your expertise!

About Numeral:Numeral is revolutionizing the tax landscape for digital businesses, helping them navigate the complexities of regulations across 47 states and over 50 countries. Our mission is to lift this burden so that teams can concentrate on their primary objectives.As the largest and fastest-growing AI-driven tax solution, Numeral was established in 2023 and has successfully raised over $57 million from notable investors such as Benchmark, Mayfield, and Y-Combinator. We proudly serve more than 2,500 paying customers and have consistently tripled our revenue year over year since our inception.While our main hiring hubs are in San Francisco and New York, we do offer remote opportunities based on specific circumstances.About the Role:We are in search of a foundational Full-Stack Engineer who thrives in dynamic environments, enjoys constructing intricate distributed systems, and is eager to establish core architecture within a rapidly expanding early-stage startup. You will spearhead the design and implementation of APIs, services, and infrastructure that form the backbone of our platform. Additionally, you will collaborate with leadership to drive engineering strategy, product execution, and cultural development.Your Responsibilities:Design and develop scalable and secure backend services and APIs from the ground up.Make architectural choices that prioritize speed, data integrity, and long-term sustainability.Work closely with product, design, and data teams to create efficient systems that enhance crucial customer workflows.Take ownership of infrastructure, observability, and performance for the services you create.Contribute to the establishment of engineering best practices, code quality, and a robust backend culture.What You Bring:Over 7 years of experience in developing backend systems in high-growth settings.Proficiency in backend technologies such as Node.js, PostgreSQL, Redis, and cloud services (AWS preferred).Experience in designing resilient APIs and distributed systems at scale.A strong product sensibility with the ability to balance performance, flexibility, and speed.A startup mindset: comfortable with ambiguity and eager for swift growth.Intensity & Ownership: This role goes beyond a standard 9-5 — we are rapidly scaling and face exciting opportunities ahead.Customer Obsession: A genuine commitment to enhancing user experience and resolving their challenges.

Join us as we create a revolutionary gamified developer platform that enables thousands of developers to engage in thrilling software engineering challenges that explore the limits of LLMs.As a Full Stack Software Engineer, you will integrate into a dynamic, enthusiastic team focused on tackling complex technical issues, crafting captivating gamification experiences, and establishing robust systems that facilitate collaboration among developers worldwide.Key ResponsibilitiesDevelop and sustain comprehensive features across both frontend and backend systems.Design scalable, high-performance backend services and user-friendly, responsive frontend interfaces to enable real-time coding competitions and engaging user experiences.Work closely with product managers, designers, and engineers throughout the stack to swiftly deliver impactful features.Lead technical discussions, influence architectural decisions, and identify areas for enhancement across the entire technology stack.Establish engineering best practices that include code quality, testing protocols, observability, and thorough documentation.QualificationsMinimum of 3 years of experience developing scalable, high-performance full stack applications in production settings.Proficient in creating frontends with React, TypeScript, and Tailwind CSS.Experience in designing secure and efficient APIs and backend services using Go.Familiar with cloud infrastructure and services (AWS) and Docker.Possess a proactive approach, comfortable with rapid iteration based on user feedback.Preferred QualificationsExperience with Infrastructure as Code (IaaC) using Terraform and CI/CD pipelines.Background in designing secure code execution environments and implementing sandboxing techniques.Interest in or experience with gamification, competitive programming, or developer-centric platforms.

Join our dynamic team at gumloop as a Full Stack Software Engineer, where you will play a pivotal role in shaping our product and impact.In this role, you will:Develop and launch comprehensive features from design through to deployment and management in a production environment.Rapidly iterate based on user feedback, ensuring swift enhancements and same-day releases.Collaborate closely with our founders daily to maintain clear priorities and eliminate obstacles.Create sleek user interfaces alongside robust backend systems that can handle increasing traffic.

Full Stack Software Engineer (Various Levels)Join our client, a pioneering organization dedicated to developing the most advanced non-invasive technology for interfacing with the human brain. They are focused on creating an innovative ultrasound-based platform that can stimulate and image brain activity with unmatched resolution and depth, unlocking new avenues in neurological treatment, research, and human health.By integrating state-of-the-art hardware, real-time software systems, and applied neuroscience into a cohesive product stack, they aim to deliver scalable solutions that enhance lives on a global scale. We are currently seeking a Full Stack Software Engineer to contribute significantly to the development of software systems that bridge complex hardware, real-time data, and user interaction.

Superhuman embraces a vibrant hybrid working model that perfectly balances focused individual work with collaborative in-person interactions to cultivate trust, innovation, and a robust team culture.About SuperhumanSuperhuman, now empowered by Grammarly, is an innovative AI productivity platform dedicated to unlocking the extraordinary potential within individuals. Our suite of applications seamlessly integrates AI into daily workflows, connecting with over 1 million applications and websites. Our offerings include Grammarly's writing enhancement tools, Coda's collaborative workspaces, Mail's inbox management solutions, and Go, our proactive AI assistant that intuitively understands context to provide timely assistance. Since our inception in 2009, Superhuman has empowered over 40 million users, 50,000 organizations, and 3,000 educational institutions worldwide, enabling them to streamline their tasks and concentrate on what truly matters. Discover more at superhuman.com and explore our core values here.The OpportunityTo fuel our ambitious growth, we are seeking talented Full-Stack Software Engineers to join our engineering teams. As a Full-Stack Engineer at Superhuman, you will be instrumental in developing key components of our product offerings, infrastructure, and features that enhance the writing capabilities of our 40 million users. This role offers a unique opportunity to engage in both Front-End and Back-End development, contributing to highly visible and impactful projects.Our engineers and researchers enjoy the freedom to innovate and drive breakthroughs that directly influence our product roadmap. As we scale our interfaces, algorithms, and infrastructure, the complexity of our technical challenges continues to grow. You can learn more about our technical endeavors on our technical blog.Superhuman is experiencing rapid growth, creating opportunities to join dynamic teams, learn from seasoned professionals, and build innovative products from the ground up. Within our expanding engineering organization, you will find ample room for ownership and a direct impact on user experience.As a Full-Stack Engineer, your responsibilities will include:Rapidly building and deploying code, with the opportunity to deliver significant features within your first few months.Developing and maintaining high-performance Back-End services and creating engaging user interfaces on the Front-End.

About ChalkChalk is at the forefront of developing a cutting-edge data platform that revolutionizes machine learning applications. We are committed to dismantling the traditional barriers of complexity, latency, and scalability that have limited ML capabilities. By merging high-performance Rust technology with user-friendly tools, we empower developers and organizations alike. Our platform is trusted by leading companies to combat fraudulent credit card transactions, validate identities, and optimize clean energy utilization. Recently, we secured a $50 million Series A funding round, spearheaded by Felicis.About the RoleWe are actively seeking passionate Full Stack Software Engineers to join our dynamic team. This is a unique opportunity to contribute significantly as an early employee within a rapidly growing startup. You will have the autonomy to tackle complex engineering challenges while taking full ownership of your work.Our ideal candidates are versatile engineers who excel at addressing business challenges across all layers of the software stack. At Chalk, we prioritize building robust data processing systems that perform efficiently at scale, all while focusing on an exceptional developer experience.We require engineers capable of crafting outstanding user experiences across both CLI and web interfaces, alongside a strong understanding of a codebase enriched with concepts from compilers, query planners, and distributed systems.Our team works in the office five days a week, with flexibility for unavoidable conflicts. Please note, this is not a hybrid position.What You Will DoCollaborate directly with Chalk’s co-founders to bring our first iteration to production.Develop applications using TypeScript, Python, Go, and React.Contribute to a codebase that incorporates advanced ideas from various fields.

Join Binti as a Senior Full Stack Software Engineer and play a crucial role in developing innovative software solutions that enhance our mission to streamline the adoption process. You will be responsible for designing, developing, and maintaining our web applications, ensuring optimal performance and user experience.In this position, you will collaborate with cross-functional teams, participate in all phases of the software development lifecycle, and mentor junior developers. If you are passionate about building scalable applications and are eager to solve complex problems, we want to hear from you!