Senior/Staff Web Platform Engineer

About PerplexityPerplexity AI’s mission is to build the world’s best answer engine and AI-native browser that make finding and understanding information effortless for everyone. The team is a fast-growing group of researchers, engineers, designers, and business leaders working together to create safe, reliable, and delightful AI products used by millions of people and organizations.About the rolePerplexity is looking for experienced Software Engineers to join a new Web Platform team. This team is critical to the development infrastructure behind Perplexity’s web-based products, including the core answer experience and the Comet AI browser surfaces.You will be responsible for building and maintaining the systems that enable Perplexity’s product teams to deliver high‑quality, performant single‑page web applications across desktop, mobile web, and the Comet browser. You will work on initiatives such as DevProd infrastructure for our SPAs, build tooling and CI pipelines, performance optimization for query and browsing flows, and migrations and refactors of core web surfaces. You will own and evolve our frontend platform, including build tools, linting and type‑safety workflows, and improved alerting and monitoring systems, to ensure fast, reliable, and consistent web experiences across multiple product surfaces.ResponsibilitiesOptimize performance for critical web flows (search, answer rendering, browsing), with a focus on improving application response speed and perceived latency.Design and implement solutions for customizable user interfaces and experience components across Perplexity and Comet.Develop and improve frontend alerting and monitoring systems to ensure reliability and rapid incident response for web experiences.Build self-serve capabilities and primitives that allow feature teams to ship frontend components and flows quickly without deep platform expertise.Support developer productivity initiatives to improve the ergonomics of web development at Perplexity (tooling, CI/CD, local dev workflows, documentation).Contribute to upgrading and maintaining core web technologies (e.g., React, TypeScript, build tooling) used across Perplexity’s web stack.Collaborate closely with product, design, search, infra, and mobile teams to deliver cohesive, performant web experiences end to end.Participate in planning and roadmap discussions to ensure appropriate scoping, sequencing, and engineering allocation for platform work.You may be a good fit if you have6+ years of practical experience as a software engineer with a strong focus on web technologies.Deep expertise in modern JavaScript frameworks, particularly React.Experience optimizing web application performance and working with metrics such as time-to-first-byte, time-to-interactive, and application response speed.A strong technical background in frontend and/or full-stack development, ideally on high-traffic consumer or prosumer products.Familiarity with frontend monitoring and alerting systems (e.g., Sentry, Datadog, Grafana, OpenTelemetry-based tooling).A track record of successfully managing technical migrations or large refactors in production web environments.Experience supporting developer productivity and building tooling or abstractions that other engineers rely on daily.Excellent collaboration skills and the ability to work effectively across product, design, and multiple engineering teams.A history of delivering high-quality, scalable software in production environments.Strong candidates may haveExperience working with AI products or integrating AI models into web applications, particularly in search, chat, or browsing experiences.Background in design systems implementation and shared component libraries used across multiple product surfaces.Experience with multi-region deployment architectures and edge rendering for low-latency global web performance.Knowledge of accessibility standards (WCAG) and practical implementation in complex, interactive web UIs.Proficiency with TypeScript and strong typing systems, including building well-typed internal libraries and SDKs.Experience with frontend performance optimization techniques (profiling, code splitting, caching strategies, image optimization, RUM).Background in building developer tools or infrastructure for web teams, such as scaffolding tools, CLIs, or shared CI/CD pipelines.