Senior Fullstack Software Engineer

About ClarionAt Clarion, we're transforming communication in healthcare through cutting-edge AI technology.Currently, clinics are missing 30–40% of patient calls, while their staff faces overwhelming administrative burdens. We envision a future where AI agents manage workflows like scheduling, billing, prescription refills, and follow-ups, allowing healthcare teams to prioritize patient care.We are developing the essential communication framework that modern healthcare demands. Our AI agents not only respond to calls—they complete entire workflows, ensuring that patients are always heard. To date, we've facilitated hundreds of thousands of patient interactions across various virtual care providers, healthcare systems, and a $5B health insurance company.Founded by a physician with training from Stanford and Harvard (part of the founding team at Two Chairs and Ophelia) and an ex-Amazon Alexa engineer who led AI/ML initiatives at Salesforce, we have secured $5.4M in funding from notable investors including Accel, Y Combinator, Sequoia (Scout), and prominent healthcare entrepreneurs. Our team operates in-person in New York, moving swiftly to tackle one of healthcare's most pressing challenges.Why This Role Is UniqueOwnership of high-impact projects: You'll be responsible for significant features and systems that are actively used in real healthcare settings.Early traction and strong signal: With numerous paying customers and increasing revenue, you'll have the opportunity to influence critical product decisions.Learn from industry leaders: Collaborate closely with founders and experienced engineers who work at the nexus of healthcare, AI, and real-time systems.Your ResponsibilitiesDevelop and maintain full-stack features that drive AI-enhanced healthcare communication.Integrate with EHRs, legacy healthcare systems, and real-time voice infrastructure.Work collaboratively with product, design, and senior engineers to turn customer feedback into deliverable software.Enhance reliability, performance, and scalability across active systems.Engage in technical discussions, code reviews, and contribute to the evolution of engineering best practices.Technical Challenges Awaiting YouAI-driven workflows: Support and expand LLM-based systems utilized in real-time healthcare interactions.Real-time systems: Contribute to low-latency services that provide seamless healthcare experiences.

About GreenboardAt Greenboard, we are pioneering the future of financial compliance. Our unified, AI-driven compliance operating system serves registered investment advisors (RIAs), fintechs, private funds, hedge funds, and beyond, replacing the disjointed array of legacy tools and automating processes beyond previous capabilities. By centralizing data and streamlining workflows, Greenboard empowers firms to mitigate regulatory risks, simplify their technology infrastructure, modernize compliance operations, and achieve cost savings.Our founding team consists of engineers who have successfully scaled products at industry giants such as Amazon and Google, as well as at several unicorn startups. Supported by esteemed investors including Y Combinator, General Catalyst, and Base10, we have raised over $20 million to date. Renowned financial institutions already trust Greenboard, and our growth trajectory is rapidly accelerating.About the Role:As a pivotal member of our engineering team, you will tackle complex technical challenges ranging from building AI agents for insider trading detection to scaling messaging archiving systems capable of processing tens of millions of messages daily. You will collaborate with a team of world-class engineers, making a significant impact on our innovative projects.This is a full-time, on-site Fullstack Software Engineer position based in New York City.Who You Are:You thrive in fast-paced environments and love to build innovative solutions.You seek deep ownership of the products you develop.You are passionate about understanding and serving the customers you build for.You possess excellent communication skills.You value teamwork and collaboration.You are based in New York City.Qualifications:3-5 years of industry experience.Proficient in Node.js and Python.Experience architecting secure, scalable systems on AWS.Experience in developing scalable data infrastructure.Knowledge of AI and machine learning algorithms.Ability to work effectively in a fast-paced startup environment.Experience in the financial industry is a plus, but not mandatory.Benefits:401(k) plan with 5% company match.Comprehensive medical, dental, and vision insurance.15 days of paid time off plus 11 company holidays and flexible sick leave.

About Waterfall:At Waterfall, we are pioneering a revolutionary trading protocol designed for rare NFTs and collectible digital art, featuring live on-chain pricing. Our mission is to enhance the liquidity and composability of NFTs by creating innovative infrastructure and auction mechanisms. We have conceptualized a unique trading system allowing users to trade shards to forecast NFT prices, enabling rapid price discovery for any listed asset.Supported by Electric Capital and Pantera Capital, our dynamic and agile team is committed to fostering an inclusive culture. We aim not only to make a significant impact in the NFT space but also to ensure that Waterfall is the ideal workplace for your future aspirations. To stay informed and connected, be sure to follow our socials and explore our website!

About ClarionAt Clarion, we are revolutionizing communication in healthcare through the power of AI.Currently, clinics are missing 30–40% of patient calls and their staff is burdened with administrative tasks. We envision a future where AI agents manage these workflows, including scheduling, billing, prescription refills, and follow-ups, allowing healthcare professionals to dedicate more time to patient care.We are developing the essential communication infrastructure that modern healthcare needs. Our AI agents do more than just answer calls—they manage workflows from start to finish, ensuring that every patient is heard. To date, we have successfully handled hundreds of thousands of patient interactions across virtual care companies, health systems, and a $5 billion health insurance provider.Founded by a physician trained at Stanford and Harvard, alongside a former Amazon Alexa engineer who led AI/ML teams at Salesforce, Clarion has raised $5.4 million from prominent investors including Accel, Y Combinator, and Sequoia. Our in-person team in New York is rapidly advancing to tackle one of the most pressing challenges in healthcare.

Join our dynamic team at counsel as a Senior Fullstack Software Engineer, where you will play a pivotal role in designing and developing cutting-edge applications. You will collaborate with cross-functional teams to build scalable and efficient software solutions. This is an opportunity to leverage your expertise in both front-end and back-end technologies to create impactful products.

About RainAt Rain, we are pioneering the future of payments on a global scale. Our dedicated team of innovative builders and seasoned founders is committed to making stablecoins practical for everyday transactions. With our advanced infrastructure, we facilitate card transactions, cross-border payments, B2B transactions, remittances, and much more. By collaborating with fintech companies, neobanks, and various institutions, we empower them to deliver solutions that are not only global but also inclusive and efficient. Join us to create significant change at a rapidly growing company backed by leading investors in the fintech, crypto, and SaaS sectors, including Sapphire Ventures, Norwest, Galaxy Ventures, Lightspeed, and Khosla. If you are driven, curious, and eager to contribute to a borderless financial future, we want to connect with you.Our PhilosophyWe embrace a culture of openness and flat hierarchies, allowing you to develop in a role that aligns with your aspirations. All team members, regardless of their position, are encouraged to explore ideas and influence the direction of the company.Role OverviewAs a Fullstack Software Engineer at Rain, you will play a pivotal role in developing our rewards and co-brand platform. Your responsibilities will include maintaining, enhancing, and building third-party rewards programs, primarily in collaboration with our major league sports partners, and integrating new payment solutions into these applications. You will take charge of the technology stack and code that underpins our rewards and co-branded payment initiatives.Key ResponsibilitiesContribute significantly to the technical and product roadmapDevelop products across our stack utilizing React, Typescript, NextJS, Tailwind, and NodeJS, focusing on RewardsLead architectural decisions and drive the technical roadmap as we scaleEngage with smart contracts across multiple blockchain networksQualificationsProficiency in JavaScript, React, Typescript, NextJS, Tailwind, NodeJS (experience in a subset of these technologies is acceptable)A passion for building, including personal projects that showcase your skillsThis role is suited for candidates with 4+ years of experience; compensation will be aligned with your backgroundPreferred QualificationsExperience in fintech (particularly with neobanks or card issuance is a plus)Familiarity with decentralized applications (dApps)

Join our dynamic team at flex as a Staff Software Engineer, Fullstack (Marketing). In this role, you will be instrumental in developing innovative software solutions that enhance our marketing efforts. You will collaborate with cross-functional teams to design, implement, and optimize our software applications, ensuring a seamless user experience.

At Plaid, we envision a future where financial interactions are seamless and transformative. Our commitment to this vision drives us to create innovative tools and experiences that empower thousands of developers in crafting their own financial products. As a pivotal player in the financial ecosystem, Plaid enables millions of users to achieve better financial health by connecting their financial accounts effortlessly to the applications they trust. We proudly partner with leading companies such as Venmo and SoFi, along with many Fortune 500 firms and major banks, to simplify financial connectivity. Our expansive network encompasses over 12,000 financial institutions across the US, Canada, the UK, and Europe. Founded in 2013 and headquartered in San Francisco, we also have vibrant offices in New York, Washington D.C., London, and Amsterdam.Plaid's mission is to democratize financial freedom for all by ensuring that money movement and access to financial data is both straightforward and secure. In the role of a Senior Fullstack Software Engineer, you will lead the design and development of systems that facilitate how millions connect with their finances.In this dynamic position, you will traverse the full technology stack, developing robust backend services and APIs while simultaneously crafting engaging, high-quality frontend experiences. This role is perfect for engineers who thrive in both backend problem-solving and frontend user interface design, eager to enhance their impact across the spectrum.You will be a key collaborator with product managers, designers, and fellow engineers to deliver products that are not only reliable and secure but also delightful for users. At Plaid, we empower our engineers to take ownership from the outset, contribute to architectural decisions, and witness their work reach millions of users.

Flex is hiring a Senior Fullstack Software Engineer to join the Risk Engineering team. This position can be based in New York, San Francisco, or remote within the U.S. Role overview This role centers on designing, building, and maintaining applications that support Flex’s risk management efforts. The Senior Fullstack Software Engineer will collaborate closely with teammates to deliver solutions that improve how risk is assessed and managed across the company. What you will do Develop and maintain both frontend and backend components for risk-related applications Work with team members to design features and solve technical challenges Contribute to projects from initial planning through deployment Requirements Experience in both frontend and backend software development Ability to drive projects through the full development lifecycle Interest in building solutions that support risk management

Role Overview Sigma Computing is growing its engineering team in New York City. The Senior Fullstack Software Engineer will help shape how users explore and interact with data. This role focuses on building technology that makes data more accessible and intuitive for a broad audience. What You Will Do Work on complex problems to create interactive experiences for data warehouse users, making analysis and exploration easier. Use modern programming languages and tools, including Rust, Go, GraphQL, and Kubernetes, throughout the development process. Build infrastructure to support Sigma Computing's cloud application. Develop algorithms and techniques that improve performance and interactivity in a multi-tenant cloud environment. Design and implement new features and technologies for a rapidly expanding user base. Collaborate across backend, frontend, design, product, customer support, sales, and marketing teams to deliver a strong product.

At StubHub, we are on a transformative journey to elevate the live event experience globally. Whether it's a person's first ticket purchase or their hundredth, our mission is to provide enjoyment and satisfaction from the moment they start their search until they enter the venue. We also cater to our sellers, from fans listing a single ticket to promoters of major tours, ensuring StubHub is the safest and most convenient platform for millions of users worldwide.Join us as a Software Engineer II, where you will be instrumental in designing and developing cutting-edge technologies and intricate features. In this role, you will face significant challenges and contribute to innovative solutions that drive our success. We seek individuals with a proactive attitude and a passion for problem-solving. Your career here will involve diverse projects aligned with business needs, and we value versatility, a growth mindset, and enthusiasm for tackling new challenges. Location: Hybrid (3 days in office/2 days remote) – New York, NY About the Team: The Consumer Experience (CX) team is dedicated to enhancing the product experience for fans discovering, buying, and selling tickets through our web and mobile platforms. We are committed to fulfilling StubHub’s mission to be the leading global destination for live events by crafting engaging experiences for millions of fans daily. Our focus is on understanding user needs and delivering both short-term and long-term feature innovations that are effective and enjoyable. With operations in over 60 regions and 30 languages, we prioritize a personalized experience for every user. Our cross-functional team collaborates on product, design, engineering, and data, fostering a culture of innovation through diversity of thought and transparency.

About N1:N1 is an innovative blockchain network that is hyper-performant and horizontally scalable. Our mission is to facilitate trustless computing at the scale of the internet, revolutionizing the way digital interactions occur.Our talented team comprises individuals with diverse backgrounds from prestigious institutions such as Harvard, Carnegie Mellon University, DFINITY, VMWare, and Galaxy Digital. We are proud to be supported by leading investment firms like Founders Fund, Kraken Ventures, SALT, and Amber Group.Position Overview:We are excited to invite a Full-Stack Software Engineer Intern to join our dynamic engineering team. This full-time role will involve the development of robust front-end, server-side, and database applications, with a primary focus on blockchain technology. Ideal candidates should be detail-oriented, innovative, and possess a strong product mindset. You will take ownership of enhancing our web platforms and internal tools, ensuring they are user-friendly, secure, and high-performing.

About Sei LabsAt Sei Labs, we are pioneers in developing open-source technology for the high-performance Sei Blockchain, the first EVM Layer 1 blockchain designed for parallelization and industry-scale performance. Our unique optimizations enable Web3 applications to achieve Web2 levels of scalability and efficiency, fostering the widespread adoption of digital assets.Our talented teams are composed of industry veterans from leading companies like Google, Goldman Sachs, Robinhood, Nvidia, and Databricks, all dedicated to onboarding the next billion users into a thriving ecosystem of applications.Having raised over $30 million from prestigious investors such as Jump Crypto, Multicoin Capital, Coinbase Ventures, Distributed Global, Hudson River Trading, and Flow Traders, we are positioned for significant growth.Discover more about us on our website and explore our documentation.About the RoleSei Labs is on the lookout for a Fullstack Software Engineer to help redefine the future of Web3 by enabling innovative, impactful applications across the Sei Blockchain. In this role, you will collaborate with a team at the leading edge of blockchain technology, working closely with our ecosystem partners to develop state-of-the-art decentralized applications (dApps) that span various Web3 domains—from decentralized exchanges (DEXs) and gaming to decentralized physical infrastructure networks (DePin), artificial intelligence, and more. If you thrive in a fast-paced, community-oriented environment and are passionate about continuous learning and rapid development, this is an exceptional opportunity to expand the frontiers of decentralized technology.

Join Flex, a rapidly growing FinTech company headquartered in New York City, as we revolutionize the rent payment process. It's 2026, and we believe that paying rent should be affordable, flexible, and hassle-free. Our mission is to empower renters with the ability to pay their rent on a schedule that aligns with their financial needs. After establishing a strong foundation of investor support and a dedicated user base, we are seeking passionate individuals to join our team and help us drive our mission forward.As a Senior Fullstack Software Engineer, you will play a crucial role in propelling our company’s growth. Your expertise will be vital in developing and scaling our platform and application experiences, ultimately facilitating our ambitious goal of achieving 10x growth.

At StubHub, we are committed to revolutionizing the live event experience on a global scale. Whether it's a fan's first concert or their hundredth game, our goal is to provide an exceptional journey from ticket search to entry. This extends to our sellers as well; from individual fans to large promoters, we aim to make StubHub the premier platform for ticket transactions worldwide.We are in search of experienced Senior Software Engineers to create innovative technologies and intricate features that enhance how millions of users discover, engage with, and attend live events globally. As a Senior Software Engineer, you will play a key role in shaping our commercial and product strategies. Your focus will be balanced between understanding user needs and making astute commercial decisions. Our Senior Software Engineers are vital to our success, demonstrating initiative and enthusiasm in addressing challenges. At StubHub, we pride ourselves on being an exceptional and inclusive workplace. You will also act as a mentor and advocate for your team members, showcasing leadership qualities.Location: Hybrid (3 days in office/2 days remote) – Aliso Viejo, CA or New York, NY or Seattle, WAAbout the Team:The Supply team's mission is to streamline the experience for our large-ticket sellers by simplifying the onboarding and inventory management process throughout the entire event lifecycle. We empower sellers to minimize operational burdens and maximize revenue through intelligent automation and efficient workflows that operate at marketplace speed. Our infrastructure consists of enterprise-grade, high-throughput systems that support core seller operations and manage extensive, dynamic datasets. Our work encompasses multiple layers of the technology stack, from robust back-end services to high-performance, user-focused interfaces, ensuring that sellers have a reliable platform they can trust to manage their business.

Join WRITER: The Future of AI-Powered WorkAt WRITER, we're revolutionizing the workplace with our cutting-edge AI solutions. Our mission is to augment human capabilities through superintelligence, enabling seamless collaboration between IT and business teams to drive transformative outcomes. Our comprehensive platform empowers renowned organizations such as Mars, Marriott, Uber, and Vanguard to create and deploy AI agents powered by WRITER's enterprise-grade LLMs. With a valuation of $1.9B and support from top-tier investors like Premji Invest, Radical Ventures, and ICONIQ Growth, WRITER is solidifying its status as a frontrunner in the enterprise generative AI landscape.Founded in 2020, we have established offices in San Francisco, New York City, Austin, Chicago, and London. Our dynamic team is fueled by a passion for innovation, and we are eager to welcome talented builders and thinkers to help shape the future of work with AI. Position OverviewWe are looking for a talented fullstack Software Engineer to join our engineering team, focusing on the development of sophisticated AI-driven agent systems. These systems will autonomously execute workflows and manage complex tasks, significantly enhancing productivity across enterprise applications. As a key contributor, you will design, develop, and scale next-generation AI agents that integrate seamlessly with enterprise data and services to address real-world challenges. Collaboration with cross-functional teams will be essential in transforming intricate agent concepts into fully operational systems.‍ Key ResponsibilitiesArchitect, implement, and sustain scalable, secure agent-driven services and systems leveraging modern AI frameworks.Build and enhance robust infrastructure and high-throughput APIs, concentrating on critical agent capabilities such as memory management, communication protocols, skills, intelligent decision-making, security, and workflow oversight.Integrate agent functionalities with backend services, data repositories, vector databases, search/retrieval systems, and third-party APIs.Work closely with product managers, AI researchers, data engineers, and UX teams to convert high-level agent use cases into resilient, production-ready software.Ensure the reliability, monitoring, and observability of all agent components, including metrics, logging, CI/CD processes, and fault tolerance.Participate in architectural design discussions and conduct thorough code reviews to maintain high-quality standards.

About SomethingsAt Somethings, we are pioneering a revolutionary social wellness platform specifically designed for teens. Our mission is to create a supportive environment where young individuals can build meaningful relationships with mentors who truly understand them, are dedicated to their growth, and provide the guidance necessary for them to flourish.In the U.S., 25 million teens face mental health challenges, and each of the countless teens who engage with Somethings requires assistance. Our goal is to ensure that these individuals do not merely use the platform, but instead connect with compassionate humans who are devoted to their well-being and help them thrive.With backing from General Catalyst and esteemed healthcare and consumer investors, we are experiencing rapid growth — achieving a remarkable 1100% increase in 2025 and aiming for a fivefold growth in 2026.If you aspire to contribute to a transformative company within the mental health sector, we welcome you to join us.Role OverviewWe are seeking a Senior Fullstack Software Engineer specializing in React to join our dynamic, high-impact engineering team. You will play a pivotal role in constructing the foundational web experiences that empower our mentors and operational teams.This position offers high levels of agency, craftsmanship, and impact:You will directly influence the platform experiences that assist teens in connecting and genuinely improving their lives.What You'll DoIn this role, you will take complete ownership of essential projects that align with our strategic objectives for 2026:1. Transform our Mentor Operations Platform into a world-class experienceDeliver web experiences that are fast, reliable, and deeply human-centric.Evolve the mentor web experience from basic functionality to a cohesive, elegant, and leading-edge platform.Create user interfaces that are as intuitive and refined as the best consumer applications.Prioritize performance, accessibility, and interaction quality.2. Develop tools that safely scale our mentor operationsDesign features for mentors that enhance consistency, speed, and connection.Implement safety measures that proactively identify risks and minimize human error.Refine mentor workflows to empower users rather than overwhelm them.3. Take charge of full-stack product developmentBuild comprehensive features across React, backend services, and APIs.Engage in close collaboration with design, product, growth, and clinical operations teams.

About ArtemisAt Artemis, we are at the forefront of a transformative shift where traditional finance is seamlessly integrating with digital finance. As a leader in this space, we are building an open data platform that consolidates and standardizes crucial metrics for blockchains, tokens, and stablecoins.Our solutions are trusted by industry giants such as Visa, Circle, Tether, Grayscale, and Franklin Templeton, and our mission is to empower individuals globally to become world-class investors in digital finance.Who We AreInspired by the resilience and determination of explorers like Ernest Shackleton, we are a dedicated team of professionals from diverse backgrounds including traditional finance and crypto. Our culture is founded on passion, mental fortitude, and the drive to tackle challenging problems. Join us if you're ready to make an impact!

About Us At Propel, we are dedicated to creating technology that enhances the social safety net. Our dynamic team of around 100 passionate individuals, known as Propellers, envisions a future where every American has access to the tools and resources required for success. The Role Are you a Fullstack Engineer eager to make a significant impact in a mission-driven environment? Do you excel in high-autonomy startup settings? If so, we want you on our engineering team at Propel. In this role, you will have the chance to switch between individual contributor and engineering management responsibilities! This position will allow you to work on various products and technology stacks, including engaging with government programs, identifying savings opportunities, facilitating user enrollment in healthcare plans, developing internal tools, and architectural design. We seek a passionate, user-focused Fullstack Engineer excited about tackling meaningful and complex technical challenges that positively influence our users’ lives. Your Impact: Strategically Lead Technical and Product Initiatives: You will play a vital role in identifying the best technical and product opportunities—whether building a new service from the ground up or advocating for significant improvements to a legacy system. Your voice will be instrumental in shaping the company’s technical and product direction, and you will take a hands-on approach to help realize these initiatives. Leading a team will also be part of your responsibilities. Set Engineering Standards: You will serve as a role model for your peers and establish best practices for technical decisions, code quality, documentation, and ensuring high-quality product delivery within timelines. Address Complex Challenges: When high-complexity tasks arise, you will be the go-to person for solutions. You will enjoy autonomy while receiving ample support to tackle these rewarding challenges!