Frontend Platform Engineer III

Calendly

5h•$156,400 - $227,424•Remote

About The Position

As a Frontend Platform Engineer on Calendly’s App Platform team, you will be instrumental in building the foundational capabilities that power our product ecosystem. Your work will directly impact how our engineering teams ship features and the quality of experience they deliver to millions of Calendly users. You will focus on critical platform services including: 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, and Developer tooling and observability infrastructure to improve engineering velocity and frontend reliability. We're at an inflection point. As Calendly continues to scale, our product teams need increasingly sophisticated frontend platform capabilities to move quickly without sacrificing quality. In this role, you’ll help evolve our shared React architecture, package ecosystem, and developer experience. You’ll contribute to engineering standards, strengthen the reliability of our frontend infrastructure, and build the resilient tooling and migration paths our growing platform demands. Your technical collaboration will help shape not only what we build, but how we build across Calendly engineering.

Requirements

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

Nice To Haves

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

Responsibilities

Design, develop, and maintain the services and frameworks that product teams depend on. You will work hands-on with technologies like React and Webpack to build highly resilient, scalable systems; from real-time server-to-client data infrastructure to shared frontend services.
Contribute to significant projects from concept to production. Whether it’s building and launching real-time server-to-client infrastructure, optimizing package performance, or designing new platform capabilities, you will deliver high impact solutions with quality and reliability at the forefront.
Partner with product managers, designers, and engineering teams across Calendly to translate their needs into robust platform solutions that serve the entire organization. You will be a connector across teams, building relationships with product engineers and acting as a trusted liaison who advocates for platform solutions that make their work easier.
Ensure reliability and performance of platform services through thoughtful monitoring, testing, and incident response. Participate in on-call rotation to support business-critical systems and drive continuous improvement based on operational learnings.