Frontend Platform Engineer III

Details

• Shared frontend packages which are used in numerous frontend web applications
• Frontend architecture and shared application scaffolding used as the foundation for new products
• Real-time UX Infrastructure to enable server-to-client data delivery to support dynamic and responsive experiences
• Developer tooling and observability infrastructure to improve engineering velocity and frontend reliability.
• 3+ years of software engineering experience at a SaaS or technology company, with a strong focus on modern frontend architecture
• Strong proficiency in React, TypeScript, and Webpack (or comparable build tooling), including application architecture, dependency management, and performance optimization
• Experience designing and maintaining shared frontend platforms, libraries, and infrastructure used across multiple teams
• Experience with package ecosystems (versioning, upgrades, migrations, and compatibility across apps)
• Experience building systems and processes that keep frontend dependencies up to date, stable, and aligned across teams
• Ability to partner with product engineering teams to improve application architecture, performance, and maintainability in React apps
• Strong debugging skills, with experience diagnosing cross-app issues spanning packages, build systems, runtime behavior, and CI/CD pipelines
• Experience supporting large-scale migrations (e.g., library upgrades, architectural shifts, routing changes, state management transitions)
• Familiarity with CI/CD pipelines, release workflows, and automation for frontend packages and applications
• Strong communication skills, able to collaborate with design system teams, product engineers, and infrastructure partners
• Authorized to work lawfully in the United States of America as Calendly does not engage in immigration sponsorship at this time
• Background in platform engineering, developer experience (DevEx), or internal tools roles
• Experience with micro-frontend (MFE) architecture, including module federation, build, deployment, and integration pipelines
• Experience authoring shared packages from scratch (e.g. datetime utilities, SSE / Server-Side Event clients, custom eslint rules)
• Experience with RTK Query cache architecture, including cache tags, optimistic updates, and strongly-typed API layers
• Experience with Storybook infrastructure and migrations, including CI integration and version upgrades
• Experience with analytics, experimentation, or feature flagging SDKs/infrastructure
• You appreciate system-level thinking and building frameworks and abstractions that make the right way the easy way for other engineers
• You are passionate about shared frontend infrastructure and treat it as a product; improving reliability, clarity, and long-term sustainability.
• You contribute to reducing single points of failure across our React ecosystem, ensuring platform knowledge is shared and durable.
• You build systems that keep our packages modern and aligned—dependency upgrades, migration paths, tooling improvements, and CI/CD automation.
• You partner with product teams to improve architecture, performance, and maintainability in their React apps.
• You thrive in collaborative environments and are energized by enabling others to ship with confidence
• You are comfortable navigating ambiguity that spans build tooling, shared packages, runtime behavior, and deployment pipelines.
• You collaborate closely with our Design System engineers, complementing their component work by strengthening the platform foundation those components rely on.
• You communicate clearly and confidently, helping teams understand architectural trade-offs and guide migrations collaboratively rather than prescriptively.
• You lead with curiosity and assume positive intent, approaching cross-team collaboration and technical disagreements with empathy and a bias toward shared understanding.
• Tier 1: San Francisco, CA, San Jose, CA, New York City, NY
• Tier 2: Chicago, IL, Austin, TX, Denver, CO, Boston, MA, Washington D.C., Philadelphia, PA, Portland, OR, Seattle, WA, Miami, FL, and all other cities in CA.
• Tier 3: All other locations not in Tier 1 or Tier 2