Senior Software Engineer - Javascript

Role Description

If you are a problem solver, have significant JavaScript experience, and you know what dynamic allocation is without having to look it up, this position is for you.

As a Senior Software Engineer at Freestar, you will be a subject-matter expert on Prebid and the header bidding ecosystem, instrumental in developing high-quality solutions that handle massive amounts of monetization opportunities for some of the world’s largest websites. This role is for someone that has experience in client side monetization and scripting, has a significant amount of experience in the ad technology industry, and has in depth knowledge of how the auction lifecycle works.

Located remotely and reporting directly to the Engineering Manager, you will play a pivotal role in our core projects. Your work will require deep programmatic advertising expertise, a high degree of autonomy, and a proactive approach to problem-solving that directly enhances the monetization capabilities of Freestar and its publishers.

This role is tailored for individuals who live and breathe ad tech and thrive in a dynamic, challenging environment. Your passion for the programmatic ecosystem and ability to navigate complex problems independently will drive our success and push the boundaries of what is possible.

Responsibilities

• Serve as a senior hands-on developer, writing and shipping production code daily, reviewing peers' pull requests, and partnering with other engineers to ensure quality across the entire codebase.
• Act as a subject matter expert for Prebid.js and Prebid Server, providing insights on wrapper architecture, bid adapters, modules (identity, consent, floors, analytics), and more.
• 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.
• Own our header bidding wrapper end to end, including architecture and release cycle, evaluating and integrating new features, and making key design decisions.
• Work daily with Google Ad Manager, GPT, and the IMA SDK, leveraging deep knowledge of GAM's features and capabilities.
• Maintain a high quality standard of code for the client-side scripts that monetize publisher sites, ensuring JavaScript and TypeScript run on thousands of publisher sites at massive scale.
• Ensure on-page performance of client-side scripts, measuring and protecting Core Web Vitals — including INP, LCP, and CLS — along with memory usage, script execution time, and network overhead.
• Take ownership of deployed solutions, ensuring ongoing reliability and addressing any critical issues as they arise, helping maintain system stability and performance.

Qualifications

• 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.

Requirements

• Contributions to Prebid.js or Prebid Server open-source repositories.

Benefits

• Full-Time, Salaried Position
• Flexible vacation policy
• The opportunity to be part of something BIG

Company Description

Freestar is a pioneering company that engineers best-in-class, cutting-edge solutions for website monetization. We achieve this by leveraging our industry-leading technology, vast data resources, and remarkable scale. Our mission is to empower Publishers to maximize their revenue potential seamlessly while freeing themselves from the burden of ad operations.

At Freestar, we believe in the power of innovation and its endless possibilities. Our team of experts is committed to delivering high-quality solutions that meet the unique needs of our Publishers and stakeholders. We are passionate about our work and strive to create a dynamic, collaborative environment that fosters creativity and innovation.