Senior Software Engineer - Javascript- AD TECH EXPERIENCE REQUIRED (Remote- US only)

Freestar develops website monetization solutions for publishers. The Senior Software Engineer will own and improve Prebid and header bidding systems, building and maintaining high-quality client-side monetization code and ensuring its performance and reliability at scale.

Responsibilities:

• You will serve as a senior hands-on developer, writing and shipping production code daily, reviewing your peers' pull requests, and partnering with other engineers to ensure quality across the entire codebase
• You will serve as a subject matter expert for Prebid.js and Prebid Server. You will be a voice on wrapper architecture, bid adapters, modules (identity, consent, floors, analytics), and more
• You will stay current on Prebid.js and Prebid Server releases, OpenRTB specification changes, and emerging standards in the header bidding ecosystem, translating those developments into concrete recommendations and upgrades for our platform
• You will own our header bidding wrapper end to end. This includes having an opinion on its architecture and release cycle, evaluating and integrating new features and making key design decisions
• You will work daily with Google Ad Manager, GPT, and the IMA SDK. Deep knowledge of GAM's features and capabilities is important in this role — line item architecture, key-value targeting, unified auction dynamics, Unified Pricing Rules, and more
• You will be responsible for maintaining a high quality standard of code for the client-side scripts that monetize publisher sites. Your JavaScript and TypeScript will run on thousands of publisher sites at massive scale
• You will be responsible for the on-page performance of our client-side scripts. You will measure and protect Core Web Vitals — including INP, LCP, and CLS — along with memory usage, script execution time, and network overhead, ensuring our monetization code enhances publisher revenue without degrading the user experience or the publisher's site performance
• You will take ownership of deployed solutions, ensuring their ongoing reliability and addressing any critical issues as they arise, helping maintain system stability and performance

Requirements:

• Deep, hands-on expertise with Prebid.js — wrapper configuration, bid adapters, modules (identity, consent, floors, analytics)
• In depth knowledge of the auction lifecycle
• Experience with Prebid Server — stored requests, server-side adapter configuration, s2s routing, and more
• Strong working knowledge of Google Ad Manager, including GPT, line item architecture, key-value targeting, unified pricing rules, dynamic allocation, and more
• 4+ years of experience in JavaScript development, with substantial TypeScript experience
• Experience with Google Cloud Platform (e.g., GKE, Cloud Run, Pub/Sub, BigQuery) for deploying and operating high-throughput services
• Broad ad tech fluency: OpenRTB, SSP/DSP integrations, identity solutions and EIDs, consent frameworks (TCF/GPP), Amazon TAM/APS, video (IMA SDK/VAST)
• Strong experience with asynchronous programming and understanding of client-server architecture
• Strong problem-solving skills and ability to work in a distributed team environment
• Excellent technical documentation and communication skills
• Ability to be creative and contribute based on your merit
• This role is not eligible for visa sponsorship
• Contributions to Prebid.js or Prebid Server open-source repositories