Smart Contract Engineer (EVM) at Waterfall | New York

About Us:Ether.fi is an innovative and rapidly expanding crypto-native financial platform dedicated to empowering users with complete control over their wealth. We simplify the processes of saving, earning, and spending cryptocurrency. As a frontrunner in the decentralized finance (DeFi) sector, ether.fi provides a comprehensive, non-custodial suite of products—Stake, Liquid, and Cash—that connect cryptocurrency utility with real-world convenience.With over $8 billion in assets under management and a dynamic team of over 25 professionals, we are constructing a sustainable, secure, and scalable financial infrastructure designed to onboard the next billion cryptocurrency users. Our offerings, which include liquid staking, automated yield strategies, and crypto-native payment solutions such as credit cards, create a holistic decentralized banking experience.As we continue to grow, we are on the lookout for talented, mission-driven individuals eager to help shape the future of finance.Discover more at ether.fi.

Ellipsis Labs is a pioneering and profitable startup based in New York, dedicated to creating innovative products and infrastructure in the realm of decentralized finance.As the developer of Phoenix, the leading order book spot exchange on the Solana blockchain, we have established ourselves as a top 10 decentralized exchange (DEX), boasting over $70 billion in transaction volume since our launch in 2023. Furthermore, we are recognized as one of the most active and influential on-chain market makers in the cryptocurrency space.All roles are based in the Ellipsis Labs office in New York City.

Join Omen as a Blockchain EngineerAt Omen, we are revolutionizing the trading landscape by creating a unified platform that allows users to trade various asset types with ultimate flexibility and efficiency.Picture a world where you can seamlessly buy spot equities and cryptocurrencies, trade on leveraged positions, short companies, or hold tokenized shares in diverse income-generating assets—all managed from a single interface without the hassle of multiple brokers or protocols.We envision a future for retail investors that mirrors the composability and power of institutional trading, ensuring speed, precision, and security.Our dynamic team consists of 8 dedicated engineers collaborating in our full-floor office located in the vibrant heart of Midtown NYC. Our collective expertise includes trading systems, startup innovation, application development, and a shared passion for our mission.Supported by leading seed investors, we are committed to relentless progress towards our ambitious goals.Role Overview:We are developing a cutting-edge perpetual derivatives platform featuring a high-performance off-chain trading engine complemented by on-chain settlement and enforcement. As a Blockchain Engineer, you will be an integral part of our blockchain team, creating the smart contract infrastructure that ensures the safety, accuracy, and enforceability of off-chain trades.Your collaboration with the trading systems team will be crucial in establishing clear and precise settlement semantics between off-chain states and on-chain finality.

About UsPaxos Labs is at the forefront of developing enterprise infrastructure that drives the next generation of trusted on-chain financial products. We collaborate with major financial institutions worldwide to create transparent and verifiable on-chain solutions tailored for everyday financial activities. If you are passionate about making decentralized finance (DeFi) and digital assets accessible to a broader audience, we invite you to explore a career with us at Paxos Labs.We are currently seeking a Smart Contract Engineer to enhance Paxos Labs' DeFi protocol infrastructure.What We're Looking ForOur smart contract team comprises skilled developers who have successfully delivered multiple decentralized applications ranging from lending markets to vaults. We seek a proactive developer who can not only craft code but also research and apply a profound understanding of DeFi to develop mission-critical software for the world's largest enterprises.Key Interests Include:DeFi Yield StrategiesTokenizationDecentralized LendingUnder/Un-Collateralized LendingKey ResponsibilitiesInvestigate and design innovative protocol mechanisms related to vaults, lending, and other DeFi primitives.Guide protocol design decisions, weighing trade-offs between trust assumptions and efficiency.Create Solidity contracts and develop comprehensive test suites for our protocols.Uphold stringent organizational and security standards for our open-source codebase.

Ellipsis Labs is a thriving and profitable startup based in New York City, dedicated to creating innovative products and infrastructure in the realm of decentralized finance.We are the proud developers of Phoenix, the foremost order book spot exchange on the Solana blockchain, and a top 10 decentralized exchange (DEX) boasting over $70 billion in volume since our inception in 2023. Moreover, we are recognized as one of the most active and reputable on-chain market makers in the cryptocurrency sector.All positions are based at the Ellipsis Labs office in New York City.The OpportunityEllipsis Labs is on the lookout for a Senior Smart Contract Engineer specializing in SVM to enhance our dynamic team. In this pivotal role, you will:Design, develop, and maintain essential smart contracts for the SVM, along with implementing the necessary monitoring systems.

Category Labs (formerly known as Monad Labs) is an innovative team of systems engineers and researchers dedicated to advancing decentralized technology. Our mission is to create groundbreaking improvements over existing blockchain solutions. Following a successful $225 million Series A funding round led by Paradigm, we are excited to expand our talented team.The RoleWe are seeking a Smart Contract Engineer to join our core engineering team, focusing on application layer development. Your responsibilities will encompass collaborating with external application and infrastructure teams and designing and implementing new primitives enabled by our high-performance Ethereum Virtual Machine (EVM) client. You will thrive in a dynamic startup atmosphere as part of a small, efficient team.What You Will DoDevelop smart contracts optimized for the resources and throughput provided by our Monad client.Assess and address the needs of the app developer ecosystem through close collaboration with the core engineering team.Engage directly with external application and infrastructure teams to provide insights and solutions drawn from your in-depth understanding of their domains and the Category Labs client.Who You AreYou possess at least 4 years of software engineering experience, including a minimum of 3 years focused on writing smart contracts in Solidity.You bring prior experience in blockchain engineering, specifically within Layer-1, Layer-2, or Infrastructure projects (such as Oracles, Bridges, Indexers, RPC Providers, Wallets, or other high-performance applications).You are proficient with tools such as Foundry and Hardhat, and you have a strong understanding of security vulnerabilities at the application layer.Your background includes backend engineering experience using low-level programming languages like C, C++, or Rust.You have successfully built significant projects from scratch, ideally with a user base (the more, the better).You are an excellent communicator, enthusiastic about engaging in technical discussions, reviews, and documentation.You embody qualities that reflect our engineering team's values, including a practical approach to problem-solving and strong design skills.

About RainRain is pioneering the future of global payments through innovative solutions. Our dynamic team is composed of experienced founders and passionate builders dedicated to making stablecoins practical for real-world applications, including card transactions, international transfers, B2B transactions, remittances, and more. We collaborate with fintech companies, neobanks, and financial institutions to create inclusive, efficient, and globally accessible solutions. Join us and be part of a fast-growing company backed by leading investors in the fintech and crypto sectors, such as Sapphire Ventures, Norwest, and Galaxy Ventures. If you are curious, daring, and eager to contribute to a borderless financial landscape, we want to connect with you.Our Company CultureAt Rain, we embrace a flat organizational structure that encourages growth and exploration. Every team member, regardless of their position, has the autonomy to innovate and influence the company's vision and roadmap.Role OverviewAs a Software Engineer focused on EVM, you will design, develop, and maintain EVM smart contracts and associated backend services. You will also contribute to our shared infrastructure across EVM, Solana, and Stellar networks. Our platform is designed to handle high transaction volumes and complex on-chain data, ensuring scalability and reliability from the outset.ResponsibilitiesLead the end-to-end development of EVM smart contracts, from design to deployment and ongoing maintenance.Develop robust and scalable backend services that interface with EVM, Solana, and Stellar networks.Enhance our on-chain infrastructure to accommodate millions of users worldwide, facilitating transaction processing, data ingestion, and real-time capabilities.Contribute significantly to the technical and product roadmap.Make critical architectural decisions in a rapidly changing environment.Quickly and iteratively deliver new features to our customers.QualificationsExtensive experience with the EVM ecosystem, including smart contract development and best practices.Proficient in Solidity programming language.Familiarity with development frameworks such as Hardhat or Foundry.

About RainAt Rain, we're revolutionizing the payments landscape by making next-generation payment solutions accessible worldwide. Our dynamic team consists of passionate innovators and experienced founders dedicated to transforming the financial ecosystem. We enable the real-world application of stablecoins through our robust infrastructure that powers card transactions, cross-border payments, B2B purchases, remittances, and more. By collaborating with fintechs, neobanks, and financial institutions, we launch solutions that are global, inclusive, and efficient. Join us at this hypergrowth company backed by top-tier investors in fintech, crypto, and SaaS including Sapphire Ventures, Norwest, Galaxy Ventures, Lightspeed, Khosla, and others. If you're curious, bold, and eager to help shape a borderless financial future, we want to hear from you!Our EthosWe foster an open and flat organizational structure where every team member can grow into the role that aligns with their aspirations. Our employees at all levels have the autonomy to explore innovative ideas and significantly influence the roadmap and vision of our company.About the PositionAs a Software Engineer, you will design, develop, and maintain Soroban smart contracts on the Stellar platform alongside backend services that integrate with them. You will also contribute to shared infrastructure across EVM, Solana, and Stellar. Our platform supports crypto-backed card products, handling high transaction volumes while continuously ingesting on-chain data and managing the unique complexities of each blockchain, with scalability and reliability built-in from the outset.Your ResponsibilitiesTake ownership of Soroban smart contracts from development through deployment and maintenance.Develop robust and scalable backend services that interact with Stellar, EVM, and Solana networks.Enhance our on-chain infrastructure to support millions of users globally, facilitating transactions, data ingestion, and real-time processing.Play a vital role in shaping our technical and product roadmap.Drive architectural decisions in a fast-paced, rapidly evolving environment.Rapidly deliver new capabilities to our customers.What We RequireExtensive knowledge of the Stellar ecosystem, including Soroban's programming model, tools, and best practices.Proficiency in Rust programming language.In-depth understanding of smart contract security patterns and common vulnerabilities.

About Baton CorporationBaton Corporation is a leading development firm that creates and manages the comprehensive technology framework for pump.fun, the foremost memecoin launchpad currently operating. Our systems are designed for low latency and high throughput, functioning under continuous real-world demand, where precision is crucial.Your RoleIn this pivotal position, you will architect, develop, and sustain on-chain programs that endure substantial real-world load. This is a hands-on opportunity that offers substantial ownership and the chance to make an immediate difference.Design and develop high-performance Solana programs using Rust, capable of managing significant transaction volumes.Conduct thorough evaluations of program correctness, security, and upgradeability within a production setting.Enhance compute efficiency, account layouts, and transaction processes to optimize for both latency and throughput.Collaborate closely with backend and frontend engineers to establish clear distinctions between on-chain and off-chain operations.Debug, test, and execute updates that go live rapidly and serve hundreds of thousands of users.Engage in design discussions regarding protocol modifications, economic mechanisms, and system limitations.Take full ownership of programs from initial design and implementation to deployment, monitoring, and iterative improvements.

Our MissionAt Alchemy, our vision is to democratize access to web3 technology for a billion users worldwide by equipping developers with the essential tools to create outstanding on-chain products. We pride ourselves on being the only all-encompassing developer platform offering robust APIs, SDKs, and tools crucial for building and scaling on-chain applications and rollups.Our infrastructure supports 70% of the leading web3 teams, over 90% of web2 companies venturing into web3, and has reached more than 100 million end users. Our clientele includes prestigious web3 brands such as Polymarket, OpenSea, and Circle, along with global giants like Shopify and Adobe.The Alchemy team is composed of experts with decades of extensive experience in scalable infrastructure, AI, and blockchain technologies, having held significant positions at renowned organizations and academic institutions like Google, Microsoft, Facebook, Stanford, and MIT.We are proudly supported by top-tier venture capitalists and institutions, including Lightspeed, Silver Lake, a16z, Coatue, Pantera, Addition, Stanford University, Coinbase, and Charles Schwab, among others.The RoleAs part of our commitment to enhancing our developer platform, Alchemy is seeking a Protocol Engineer to design and construct distributed protocols. You will be responsible for architecting these protocols, ensuring high standards of readability, optimization, and security, all backed by a comprehensive testing suite. Your contributions will mirror the security, speed, and stability of our existing platform, impacting thousands of teams and millions of users globally.What You Will Do:Architect and design distributed protocols focusing on security, performance, and scalability.Write, deploy, and test smart contracts, ensuring their maintenance in production.Develop and uphold best practices for protocol upgrades and versioning across different networks.Collaborate with engineering, product, and design teams on user-facing applications built around our smart contract protocols.Mentor fellow engineers in advanced Solidity/EVM topics and best practices.Stay current with the latest Solidity releases, developer tools, and potential exploits.What We Are Looking For:6+ years of relevant industry experience.2+ years in smart contract development, including production deployments of original, non-trivial protocols and associated security audits.Bachelor's degree in Computer Science or related field.Exceptional proficiency with Solidity and the EVM.Experience in designing distributed protocols.

Mark43, a leading provider of innovative public safety software, is on the lookout for talented Staff Engineers to join our dynamic team. Our mission is to empower communities and their governments with cutting-edge technologies that enhance safety and improve quality of life. We are committed to fostering a diverse environment that values the unique experiences and perspectives of our team members.As a Staff Engineer at Mark43, you will play a pivotal role in developing the next generation of cloud-based public safety solutions. You will take ownership of projects and features from inception to deployment, providing your expertise to guide and support your colleagues. Your work will involve creating robust server-side solutions that address our challenges of scale, security, and reliability. We leverage a modern tech stack, including Java, MySQL, Redis, and Elasticsearch, and actively engage with the open-source community. This is an opportunity for you to implement your own creative solutions and have a meaningful impact on the tools used by first responders.

About Us:At Camber, we are dedicated to revolutionizing healthcare through innovative software solutions. Our mission is to enhance the quality and accessibility of healthcare by eliminating tedious manual tasks, allowing clinicians to concentrate on what truly matters: delivering exceptional care. To learn more about our vision, please visit our detailed write-up: What is Camber?We have successfully secured $50M in funding from prestigious investors including a16z, Craft Ventures, YCombinator, Manresa, and others who are passionate about improving healthcare accessibility. For further insights, check out: Announcing CamberCompany Culture:Our commitment to transforming behavioral health is deeply ingrained in our operations. We aim to not only innovate in behavioral health but also redefine how startups function. Here are key aspects of our culture:1) We are passionate about enhancing healthcare accessibility and quality; every member of the Camber team is devoted to supporting clinicians and patients alike.2) We believe in the power of humor. The complexities of the healthcare system can be overwhelming, and we choose to tackle them with a light-hearted approach.Role Overview:As a Senior Staff Software Engineer at Camber, you will play a crucial role in crafting reliable, high-quality software that addresses significant challenges and drives essential workflows. You will provide technical leadership, oversee comprehensive solutions, and foster growth within your team.Key Responsibilities:Lead Technical InitiativesFacilitate architectural discussions and guide technical decision-making within your team.Establish and uphold standards for quality, performance, maintainability, and scalability.Oversee End-to-End Project DeliveryLead the execution of intricate features from design through to production deployment.Ensure the reliability, performance, and scalability of all delivered solutions.Mentor and Develop Team MembersGuide engineers through pair programming, code reviews, and design discussions.Cultivate a culture of continuous learning and improvement within the team.Drive InnovationPropose and implement improvements to enhance overall process and product quality.

Join the Innovative Team at FLORAAt FLORA, we empower the new creative class with cutting-edge tools that redefine creative expression. Our intelligent canvas integrates advanced AI models to facilitate professional-grade craftsmanship. Backed by $52 million in funding from top-tier investors like Redpoint Ventures and Menlo Ventures, we are a dynamic team of around 20 dedicated to serving a diverse clientele, including renowned brands like Pentagram, Lionsgate, and Nike.About the PositionWe are in search of a Staff Product Engineer who will take ownership of essential elements of FLORA's product. As a technical leader, you will influence our frontend systems, focusing on canvas rendering, intricate workflow interactions, and the media layer crucial for image and video editing.We need a candidate who is passionate about their craft, delivers polished work swiftly, and continuously enhances it until it stands out. You will have significant influence over the technical direction and the opportunity to shape the future of our product engineering team.In This Role, You Will:Create canvas and workflow systems that simplify complexity, enabling users to effortlessly manage intricate, multi-step pipelines.Enhance our media control layer to expand image and video editing functionalities.Deliver high-performance, visually stunning UI that meets the expectations of creative professionals.Make architectural decisions throughout our frontend stack (Next.js, Zustand, React Flow, Convex, Vercel).Implement features that encompass the entire stack.Ideal Candidates Will Have:7+ years of experience developing web applications, with a proven track record of delivering polished products at scale.5+ years of extensive experience with React and TypeScript, possessing strong views on component architecture, state management, and performance optimization.Hands-on experience in creating high-performance, visually appealing web applications.Experience in building successful products from the ground up.Demonstrated technical leadership skills: guiding direction, making architectural choices, and uplifting fellow engineers.Exceptional Candidates Might Also Possess:Experience with AI-driven applications.Familiarity with specialized web media APIs: WebGL (@react-three/fiber), WebGPU, WebCodecs, or WebAssembly.

Join Crosby as a Staff Frontend Engineer, where you will lead the development of innovative web applications that enhance user experiences. Collaborate with cross-functional teams to design, implement, and maintain scalable software solutions. Your role will involve mentoring junior developers, conducting code reviews, and ensuring best practices in frontend development.

Join Campus as a Staff Platform Engineer, where you'll play a crucial role in shaping our platform’s architecture and enhancing our technological capabilities. You will collaborate with cross-functional teams to design, develop, and maintain scalable solutions that power our innovative educational initiatives.

Role Overview AlphaSense is hiring a Senior or Staff Design Engineer. This role can be based in New York, NY or remote within the United States. The engineer in this position will help shape new solutions and influence product direction. What You Will Do Apply deep design engineering experience to product development projects Contribute to building and refining user experiences Work closely with other engineers and teams to deliver high-quality solutions

At Forge, we recognize that our team is our most valuable asset. As pioneers in the technology sector of the private market, we envision a future enriched for all. We embody this vision through our core values of boldness, accountability, and humility. Daily, we witness the impact of our vision, assisting the teams that drive the most significant innovations of our time, from space exploration to artificial intelligence, and beyond. With an array of liquidity solutions, exclusive data insights, a custody offering, and a dynamic marketplace, Forge is dedicated to developing a top-tier technology infrastructure that fuels a global private market characterized by transparency, accessibility, and seamless interactions for companies, their employees, and investors. Through Forge, employees can liquidate their private shares, employers can provide pre-IPO liquidity to shareholders, and individual and institutional investors can engage in the growth of private unicorns. Our distinctive global marketplace meets the increasing demand from individual and institutional investors seeking exposure to private company stocks, fostering a growing network effect. Our capability to deliver these impactful financial solutions has sparked remarkable interest from investors, heightened demand from clients, and a pressing need to expand our team to cater to an increasing number of companies, teams, and innovators in this manner. The Role: The platform engineering team at Forge is driven by a passion for innovation and the creation of scalable, secure infrastructure solutions that facilitate liquidity and growth within the private market. Our teams are harnessing a diverse range of technologies to support our core platform, Metal, and we excel in moving swiftly, delivering value, and upholding our principles of being bold, humble, and accountable.We are on the lookout for a dedicated platform engineer with a minimum of 7 years of experience in delivering robust infrastructure solutions that are scalable, secure, and easy to maintain. The ideal candidate thrives in collaborative environments and is driven by the desire to foster success around them through effective communication, architecting exceptional developer experiences, and making informed, data-driven decisions.To thrive in the Staff Platform Engineer position at Forge, you will leverage your infrastructure and software expertise to deliver high-quality platforms both independently and through guiding others. You will have the opportunity to tackle advanced infrastructure projects—from multi-cluster orchestration to automation of SOC 2 compliance—while also being a productive and cooperative member of our team.Location: This role requires 2-3 days a week in office in Soho, NY.

Playground builds software to help child care providers manage their businesses more efficiently. The platform supports thousands of schools across the United States, with a focus on making high-quality child care more accessible. The company has secured millions in funding and holds several statewide contracts, reflecting strong momentum in the education technology space. Playground’s founders have been recognized on the Forbes 30 Under 30 list for their work in child care technology. The team values a culture where ownership and collaboration are central. Engineers at Playground regularly work together on challenging projects that have a direct impact on customers and the broader child care sector. Role overview This Staff Software Engineer position is based in New York City. The role centers on building and improving Playground’s core products as the company grows. Engineers here contribute to significant technical decisions and help shape the future of the platform. What you will do Work on complex software projects that support child care businesses nationwide Collaborate closely with other engineers and teams to deliver high-impact solutions Take ownership of technical challenges and contribute to a culture of shared responsibility Requirements Experience leading or contributing to large-scale software projects Ability to work effectively in a collaborative, team-driven environment Based in or willing to work from New York City

At Partiful, we are on a mission to foster friendships through unforgettable social events.We believe that gatherings—be it parties or other social events—serve as the best medium to meet new people and build lasting friendships. Our innovative platform empowers users to host extraordinary events, beginning with engaging party pages that simplify planning and enhance communication with guests. Download our app to experience our service firsthand!As we continue to innovate, we're focused on creating seamless ways to plan events, facilitating meaningful connections in real life, and bridging relationships among friends of friends. Our ultimate goal is to enhance every in-person interaction with friends, removing the barriers to creating memorable experiences. Explore more about our vision in The Washington Post, The New York Times, The Wall Street Journal, The Atlantic, Wirecutter, and USA Today. Partiful has been recognized as Google’s Best App of 2024, a Finalist for Apple’s App Store Awards, and celebrated as Apple’s App of the Day multiple times. In 2025, we proudly earned a spot on TIME's 100 Most Influential Companies list.