Job Url: https://builtin.com/job/senior-frontend-engineer-activation-and-engagement-web-growth/6816836 Job Description: Block Senior Frontend Engineer, Activation and Engagement Web (Growth) Job Posted 7 Days Ago Posted 7 Days Ago 7 Locations In-Office or Remote 185K-327K Annually Senior level Blockchain • eCommerce • Fintech • Payments • Software • Financial Services • Cryptocurrency Block builds technology for economic empowerment. The Role Design and implement scalable frontend features using modern web frameworks, lead architecture improvements, mentor engineers, and enhance seller experiences. Summary Generated by Built In Block is one company built from many blocks, all united by the same purpose of economic empowerment. The blocks that form our foundational teams - People, Finance, Counsel, Hardware, Information Security, Platform Infrastructure Engineering, and more - provide support and guidance at the corporate level. They work across business groups and around the globe, spanning time zones and disciplines to develop inclusive People policies, forecast finances, give legal counsel, safeguard systems, nurture new initiatives, and more. Every challenge creates possibilities, and we need different perspectives to see them all. Bring yours to Block. The Role The Activation and Engagement Web team is a critical part of Square's Growth Product organization, with a mission to help sellers start, run, and grow their businesses with Square. As part of the Growth strategy to Simplify, Automate, and Graduate seller experiences, we build and maintain the frontend experiences and supporting infrastructure that guide sellers from signup through their first payment and into ongoing product engagement. We enable both end-to-end seller journeys and the platform capabilities that empower other teams to build exceptional web experiences-through shared components, frameworks, and extensible architecture. Our focus is on automating complex workflows and removing friction from key seller moments, with a direct impact on Square's growth initiatives. We're looking for a Senior Frontend Engineer (L6) to help us scale our platform, deliver high-impact features, and mentor fellow engineers. You'll contribute to and evolve the technical vision for the Activation Web platform, defining best practices within the Activation Web team and collaborating with adjacent Growth squads. This role blends team leadership with hands-on execution to shape the systems and experiences that power millions of seller interactions. You Will Design and implement user-facing features and frontend architectures at scale primarily using React and Next.js , and occasionally using Ember and Svelte. Build and maintain performant, accessible, and reliable web applications. Own the full feature lifecycle - from requirements gathering through implementation, testing, deployment, and monitoring. Contribute to shared component libraries and frameworks that accelerate development across Growth teams. Collaborate with backend, mobile, and design teams to prototype and iterate on new seller experiences. Lead team-level architecture improvements (e.g., Ember deprecation), championing performance, maintainability, and accessibility best practices. Design and build scalable product infrastructure and platform capabilities that support both our team and broader engineering teams, with a focus on solving problems at the platform level beyond individual user-facing features. Participate in incident response and root-cause analysis for production issues. Mentor and coach mid-level and junior engineers through code reviews and pair-programming. Foster a culture of technical excellence, inclusion, and high-velocity execution. Explore and apply emerging technologies - including AI-assisted tooling to improve engineering workflows and seller experience. You Have 8+ years of professional experience with JavaScript/TypeScript and modern web frameworks (React, Next.js). Hands-on experience building and operating large-scale web applications with dozens of active contributors. Proven ability to lead large projects from start to finish, with strong collaboration, communication, and ownership. Deep expertise in performance tuning, accessibility compliance, and frontend observability (monitoring, SLOs, SEV response). Proven track record of owning production services and driving operational excellence (SLOs, monitoring, SEV response). Strong component-driven development skills and familiarity with design-system tooling (e.g., Storybook). Excellent communication and collaboration skills, with experience working on cross-functional teams in a fast-paced environment. Familiarity with cloud infrastructure (AWS, Kubernetes) and CI/CD pipelines for frontend deployments. Curiosity about emerging technologies and a practical mindset for applying them in system design and workflow improvement. Even Better Experience in growth or activation engineering: onboarding flows, A/B testing, and conversion funnel instrumentation. Data engineering and analytics proficiency, including advanced SQL querying, statistical analysis, and the product intuition to turn insights into impactful features. History of owning and evolving a shared UI library in a monorepo or similar setup. Startup experience. Technologies We Use and Teach Languages: TypeScript/JavaScript (Primary), Java Frameworks & Core Technologies: Next.js, React, Ember, Svelte, Node.js APIs & Communication: gRPC, REST, Protocol Buffers, GraphQL Experimentation: Optimizely, LaunchDarkly Testing: Jest, Playwright Tools: Remix, React Router, Vite, React Query, Snowflake, Sentry, Datadog We're working to build a more inclusive economy where our customers have equal access to opportunity, and we strive to live by these same values in building our workplace. Block is an equal opportunity employer evaluating all employees and job applicants without regard to identity or any legally protected class. We will consider qualified applicants with arrest or conviction records for employment in accordance with state and local laws and "fair chance" ordinances. We believe in being fair, and are committed to an inclusive interview experience, including providing reasonable accommodations to disabled applicants throughout the recruitment process. We encourage applicants to share any needed accommodations with their recruiter, who will treat these requests as confidentially as possible. Want to learn more about what we're doing to build a workplace that is fair and square? Check out our I+D page . While there is no specific deadline to apply for this role, U.S. roles are typically open for an average of 55 days before being filled by a successful candidate. Please refer to the date listed at the top of this job page for when this role was first posted. Block takes a market-based approach to pay, and pay may vary depending on your location. U.S. locations are categorized into one of four zones based on a cost of labor index for that geographic area. The successful candidate's starting pay will be determined based on job-related skills, experience, qualifications, work location, and market conditions. These ranges may be modified in the future. To find a location's zone designation, please refer to this resource . If a location of interest is not listed, please speak with a recruiter for additional information. Zone A: $217,800 - $326,800 USD Zone B: $207,000 - $310,400 USD Zone C: $196,100 - $294,100 USD Zone D: $185,200 - $277,800 USD Every benefit we offer is designed with one goal: empowering you to do the best work of your career while building the life you want. Remote work, medical insurance, flexible time off, retirement savings plans, and modern family planning are just some of our offering. Check out our other benefits at Block. Block, Inc. (NYSE: XYZ) builds technology to increase access to the global economy. Each of our brands unlocks different aspects of the economy for more people. Square makes commerce and financial services accessible to sellers. Cash App is the easy way to spend, send, and store money. Afterpay is transforming the way customers manage their spending over time. TIDAL is a music platform that empowers artists to thrive as entrepreneurs. Bitkey is a simple self-custody wallet built for bitcoin. Proto is a suite of bitcoin mining products and services. Together, we're helping build a financial system that is open to everyone. Read Full Description Top Skills AWS Ember JavaScript Kubernetes Next.Js Node.js React Svelte Typescript What The Team Is Saying Scott Maher Engineering Lead “In Compliance Engineering, we work across all product teams and have the space to really understand how new features will improve the lives of customers. Since all data streams to us, we can design systems that solve entire categories of problems, like visualizing money flow, cryptocurrencies, and stopping bad actors from causing harm.“ View all jobs at Block View Block Profile Report Job Am I A Good Fit? beta Proven ability to lead large projects from start to finish Deep expertise in performance tuning and accessibility compliance Strong component-driven development skills and familiarity with design-system tooling Excellent communication and collaboration skills Familiarity with cloud infrastructure and CI/CD pipelines 8+ years of professional experience with JavaScript/TypeScript and modern web frameworks Hands-on experience building and operating large-scale web applications ANALYSIS BASED ON YOUR RESUME: Maxwell_Reshel-Software Engineer, Mobile-Vivian Health.docx To select or upload a new resume, visit edit profile. The Company HQ: Oakland, CA 12,000 Employees Year Founded: 2009 What We Do Block, Inc. is a global technology company with a focus on financial services. Made up of Square, Cash App, Afterpay, TIDAL, Bitkey, and Proto, Block, Inc. builds technology to increase access to the global economy. Each of our brands unlocks different aspects of the economy for more people. Square makes commerce and financial services accessible to sellers. Cash App is the easy way to spend, send, and store money. Afterpay is transforming the way customers manage their spending over time. TIDAL is a music platform that empowers artists to thrive as entrepreneurs. Bitkey is a simple self-custody wallet built for bitcoin. Proto is a suite of bitcoin mining products and services. Together, we’re helping build a financial system that is open to everyone. Why Work With Us Block builds simple, powerful tools that make progress towards an economy that’s truly open to all. Gallery Block Teams LEARN MORE Our Ecosystem ABOUT OUR TEAMS Block Offices LEARN MORE Remote Workspace Employees work remotely. At Block, your benefits evolve with you. Whether you’re planning for your financial future, prioritizing flexibility, or focused on well-being, we’ve got you covered. Competitive pay & health coverage form the foundation, but our benefits go further. Typical time on-site: None HQOakland, CA Tech Central Sydney Atlanta, GA Auckland, NZ Boston, MA Chicago, IL Chisinau, MD Denver, CO Dublin, IE Kitchener, Ontario London, GB Los Angeles, CA Melbourne, Victoria New York, NY Oslo, NO Portland, OR Saint Louis, MO Salt Lake City, UT San Francisco, CA Scottsdale, AZ Seattle, WA Tokyo, JP Toronto, Ontario LEARN MORE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Similar Jobs