Full Stack Software Engineer at gumloop | San Francisco

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 the Role Siftstack is seeking a Software Engineering Manager (Data) in San Francisco. This leader will guide a skilled team of engineers focused on building data solutions. The role involves setting engineering strategy, overseeing software quality, and supporting a culture that values innovation and high standards. What You Will Do Lead and mentor a team of data engineers Shape and drive the engineering approach for data projects Oversee delivery of reliable, high-quality software Encourage new ideas and continuous improvement within the team Location This position is based in San Francisco, CA.

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.

About Siftstack Siftstack builds core infrastructure for engineering teams designing, testing, and operating complex machines. The platform delivers real-time observability for high-frequency telemetry, helping engineers debug issues quickly, spot failures early, and maintain reliable operations where precision matters most. The founding team brings experience from SpaceX, Google, and Palantir, with backgrounds in projects like Dragon, Falcon, Starlink, and Starship. Siftstack’s technology supports organizations in aerospace, defense, robotics, energy, and industrial sectors, fields where speed and dependability are essential. Role Overview: Enterprise Account Executive The Enterprise Account Executive leads technical sales cycles with engineering teams working on advanced systems. This role partners with Solutions Engineering, Product Management, and leadership to find new opportunities, guide technical evaluations, and close deals that make a real impact for engineering customers. Siftstack looks for someone who thrives on selling technical products, enjoys working directly with engineers, and wants to shape the go-to-market approach of a growing company. What You Will Do Drive New Customer Acquisition Find and develop new business with engineering-driven organizations across the United States. Reach out to target accounts and build relationships with both technical and executive contacts. Create account strategies and manage a pipeline of qualified opportunities. Lead Technical Sales Cycles Run discovery sessions to understand system architecture, telemetry needs, and engineering pain points. Work with Solutions Engineering and Product teams to support technical assessments and pilot projects. Define success criteria and guide evaluations toward clear technical and business goals. Close High-Value Deals Manage deals from first contact through contract signing. Align technical validation with commercial buying processes. Handle procurement steps to ensure deals close successfully. Location This position is based in San Francisco, CA.

At Sift, we are revolutionizing the way sophisticated machines are constructed, tested, and managed. Our innovative platform provides engineers with instantaneous visibility over high-frequency telemetry, effectively removing bottlenecks and fostering swifter, more dependable development.Originating from our extensive experience at SpaceX on projects such as Dragon, Falcon, Starlink, and Starship, Sift was created to address the challenges of scaling telemetry, debugging flight systems, and ensuring mission reliability, which necessitated the development of groundbreaking infrastructure. Established by a talented team from SpaceX, Google, and Palantir, Sift is tailored for mission-critical systems where accuracy and scalability are imperative.As a key early engineer concentrating on our data infrastructure, your role will extend beyond mere coding—you will shape foundational architecture and assist in scaling a real-time telemetry platform from its inception. You will engage with intricate backend systems designed to process, store, and deliver millions of high-frequency data points each second, facilitating rapid iteration cycles for some of the world's leading engineering teams.

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.

At Sift, we are revolutionizing the construction, testing, and operation of modern machines. Our innovative platform empowers engineers with real-time visibility over high-frequency telemetry, helping to eliminate bottlenecks and facilitating rapid, reliable development.Founded by a team with backgrounds at SpaceX, Google, and Palantir, Sift emerged from the need for robust infrastructure in mission-critical systems, where precision and scalability are paramount. With roots in projects like Dragon, Falcon, Starlink, and Starship, we focus on delivering solutions that address complex engineering challenges.As a pivotal member of our engineering team, you will not only write code but also define architecture, shape product development, and influence a culture dedicated to solving real-world engineering problems. If you are eager to tackle intricate technical challenges and contribute to building foundational systems for complex machines, we would love to hear from you.

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.

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.

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.

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!

About AnonAnon is revolutionizing the way enterprises can deploy authenticated AI agents to enhance their crucial data workflows.We are tackling one of the most significant challenges in enterprise automation: extracting and transforming data that is hindered by authentication barriers. Our innovative platform empowers AI agents to securely connect with any web-based system, extract unstructured data, and present it through state-of-the-art APIs.Since our inception in 2023, we have partnered with industry leaders to convert lengthy manual processes into streamlined automated workflows that can be completed in mere minutes. With $14M raised from notable investors such as Union Square Ventures, Forerunner Ventures, Okta Ventures, and Abstract Ventures, we are on a path of rapid growth.Our vision is clear: we believe every business system should be accessible to AI agents. If you are passionate about developing infrastructure that will support the next wave of AI applications, we invite you to join our dynamic team of 12 in San Francisco.www.anon.com/careersAbout the RoleAs a Full Stack Engineer at Anon, you will play a pivotal role in creating both the user interfaces and the underlying infrastructure that drive our authenticated AI agents for enterprise workflows. Your responsibilities will include developing React-based dashboards for agent monitoring, crafting embeddable authentication components, and constructing the APIs and data pipelines that convert unstructured web data into accurate and reliable outputs. This is a chance to take ownership of features from inception to deployment while engaging at the intersection of AI and enterprise software.Key ResponsibilitiesCore Platform DevelopmentCreate robust AI agents capable of navigating web interfaces, managing dynamic content, and extracting data from systems lacking APIs.Develop front-end interfaces for agent creation, monitoring dashboards, and real-time execution visualization.Take full ownership of features from database to UI, encompassing API design and user experience.Design embeddable JavaScript components and authentication modals to facilitate customer integrations.Build and maintain scalable APIs, data pipelines, and authentication workflows across various platforms.Develop integrations with third-party services and ensure comprehensive test suites are maintained.Collaborate & LearnPartner with senior engineers to gain insights into system architecture and best practices.Engage in code reviews and share knowledge with your peers, fostering a culture of continuous improvement.

Join Clipbook in reshaping how leaders engage with the world!As the frontrunner in vertical AI for the $100 billion communications, public relations, and public affairs industries, we are on a remarkable journey.Founded in 2023, we've rapidly established ourselves as the largest AI company in this segment, backed by prominent investors like Mark Cuban, who co-led our seed funding round.Learn more about our achievements:Achieved our first million in ARR through bootstrapping and reached profitability before securing a $3.3 million seed round this year.Currently experiencing over 10% month-over-month growth, on track to triple our ARR this year.Partnering with over 200 clients, including the Boston Consulting Group, Weber Shandwick, the Gates Foundation, and various government agencies nationwide.Planning to raise our Series A in early 2026.Your Role:Architect & Build: Make key architectural decisions and implement solutions across the stack (NextJS, TypeScript, React, Python, Node, SQL/NoSQL). You will bring concepts to life, deploying solutions that delight our clients.Collaborate with Customers: Engage directly with users to understand their challenges, iterate swiftly, and provide impactful solutions.Address Diverse Engineering Challenges: Work spans AI, data engineering, and backend development, providing opportunities to tackle projects that align with your strengths. Examples include:AI/ML Integration: Implement LLMs and classical ML models for real-world applications with high uptime. Utilize cutting-edge generative AI tools and frameworks.Data Engineering: Develop pipelines and infrastructure for managing large, multi-modal datasets.Shape Clipbook’s Engineering Culture: As an early team member, you will set engineering standards, mentor future hires, and drive best practices in code quality, testing, and deployment while shaping the team’s culture.