Reddit is a community of communities. It’s built on shared interests, passion, and trust, and is home to the most open and authentic conversations on the internet. Every day, Reddit users submit, vote, and comment on the topics they care most about. With 100,000+ active communities and approximately 130 million daily active unique visitors, Reddit is one of the internet’s largest sources of information. For more information, visit www.redditinc.com. Team Description The Ad Formats team builds and evolves Reddit’s ad experiences across all platforms and all format types, including image, video, carousel, shopping, etc.    The team defines how those ads behave across placements like feed, conversation, search, making sure each format works in the right surfaces and contexts across Reddit. The team supports the end-to-end user ad experience, including media rendering, click behavior, special click variants like lead gen, and the UI details that make promoted content feel native to Reddit while optimizing for advertiser's goals.   Within this area, the Ad Formats Foundation team owns the common infrastructure behind all ad formats, with a mission to improve developer efficiency, system reliability, and long-term scalability across the stack. We are responsible for modernizing core formats infrastructure, standardized format data, drive cross-platform consistency and compliance for ad formats to reduce bugs and allow the formats team to iterate quickly and improve the developer velocity.    Our goal is to continuously improve ad formats infrastructure, with a focus on increasing developer efficiency and system reliability through tech stack modernization, scalability investments, and compliance work. Role Description We’re looking for a senior frontend engineer with deep JavaScript, TypeScript, and browser platform expertise to help strengthen Reddit’s advertising experiences across desktop and mobile web. You will partner with product and design to work through ambiguous requirements and make sound product and engineering tradeoffs.   You’ll work closely with Ads and Web Platform engineers to solve complex frontend challenges while maintaining site performance, accessibility, and a dependable user experience. This role is a strong fit for someone who enjoys browser-level problem solving, navigating ambiguity, and building maintainable systems with measurable impact. Responsibilities • Develop resilient frontend approaches to reduce ad disruptions, drawing on deep knowledge of JavaScript, TypeScript, HTML, CSS, the DOM, and browser networking. • Partner with Ads and Web Platform teams to integrate solutions into shared rendering infrastructure, frontend architecture, and build systems. • Design controlled experiments and phased rollouts to measure effectiveness while protecting site performance, accessibility, and user experience. • Build instrumentation and monitoring to track mitigation effectiveness, detect regressions, and guide iteration. • Implement ad rendering, event collection, click handling, browser extensions across multiple Ad formats. • Contribute to broader foundational improvements in web advertising reliability, performance, and measurement. • Raise engineering quality through thoughtful technical design, testing, code reviews, documentation, and mentorship. Required Qualifications • 5+ years of experience building production web applications with JavaScript, TypeScript, and/or React. • Comfort using Codex, Cursor, Claude, or comparable agentic coding tools in day-to-day software development. • A track record of independently delivering complex frontend projects from technical design through launch and iteration. • Sound judgment in frontend architecture, state management, component design, testing, and API integration. • Experience building polished user interfaces with close attention to usability, performance, accessibility, and maintainability. • Ability to work effectively through ambiguous product and technical problems. • Strong communication and collaboration skills across engineering, product, design, and data disciplines. • Experience using instrumentation, experimentation, or product metrics to understand and improve user experiences. • A habit of improving engineering quality through code reviews, documentation, and technical mentorship. Bonus points • Experience working with various ad formats (video ads, display ads, etc) Technologies used on the team include • JavaScript, Typescript and React • Modern frontend testing, experimentation, and observability tools Benefits:  • Comprehensive Healthcare Benefits and Income Replacement Programs • 401k Match • Family Planning Support • Gender-Affirming Care • Mental Health & Coaching Benefits • Flexible Vacation & Reddit Global Days Off • Generous paid Parental Leave   • Paid Volunteer time off #li-remote Pay Transparency: This job posting may span more than one career level. In addition to base salary, this job is eligible to receive equity in the form of restricted stock units, and depending on the position offered, it may also be eligible to receive a commission. Additionally, Reddit offers a wide range of benefits to U.S.-based employees, including medical, dental, and vision insurance, 401(k) program with employer match, generous time off for vacation, and parental leave. To learn more, please visit https://www.redditinc.com/careers/. To provide greater transparency to candidates, we share base salary ranges for all US-based job postings regardless of state. We set standard base pay ranges for all roles based on function, level, and country location, benchmarked against similar stage growth companies. Final offer amounts are determined by multiple factors including, skills, depth of work experience and relevant licenses/credentials, and may vary from the amounts listed below. The base salary range for this position is: $190,800—$267,100 USD In select roles and locations, the interviews will be recorded, transcribed and summarized by artificial intelligence (AI). You will have the opportunity to opt out of recording, transcription and summarization prior to any scheduled interviews. During the interview, we will collect the following categories of personal information: Identifiers, Professional and Employment-Related Information, Sensory Information (audio/video recording), and any other categories of personal information you choose to share with us. We will use this information to evaluate your application for employment or an independent contractor role, as applicable.  We will not sell your personal information or disclose it to any third party for their marketing purposes.  We will delete any recording of your interview promptly after making a hiring decision.  For more information about how we will handle your personal information, including our retention of it, please refer to our Candidate Privacy Policy for Potential Employees and Contractors. Reddit is proud to be an equal opportunity employer, and is committed to building a workforce representative of the diverse communities we serve.  Reddit is committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. If, due to a disability, you need an accommodation during the interview process, please let your recruiter know.