JavaScript Engineer

The Inventory Quality team at Quantcast is responsible for ensuring that we only run our customers’ ads on brand-safe, fraud-free sites and to real humans.  We are looking for experienced JavaScript engineers to help with this mission.
As a JavaScript Engineer, you write client-side JavaScript to capture and process anonymous ad and Internet usage data on millions of pageviews per day. This data informs advertising purchasing strategy and our anti-fraud and brand safety systems. You care about clean and performant code, how to test code effectively across browsers and how to A/B test new features online.


  • Design and improve JavaScript that renders ads intelligently on websites
  • Write JavaScript that collects contextual browser information and behavioural data across millions of websites and users
  • Build browser extensions and crawlers that track advertising trends across the web
  • Work with data scientists to invent novel approaches to fighting fraudulent ad traffic 


  • BS in Computer Science, related field or equivalent experience
  • Expert knowledge of JavaScript and object-oriented programming with JS
  • Deep understanding of cross-browser differences
  • Knowledgeable in JS programming best practices and design patterns
  • Ability to write modular, testable, and readable JS code
  • Understanding of JS performance tradeoffs, and profiling and debugging tools
  • Working knowledge of test frameworks
  • Resourceful, experimentation-driven approach to solving unstructured, data-oriented JS challenges

Quantcast helps create a more personalized digital world. We have built one of the world’s most sophisticated data-intelligence platforms, use big data and machine learning to solve the biggest challenges in marketing and create more rewarding experiences across the digital landscape. Publishers use our insights to better understand audiences and how content resonates with consumers they want to attract and retain. Marketers utilize our understanding of online behavior and our predictive advertising capabilities to reach the customers likeliest to engage with their messages. Consumers see the results of our work in relevant stories and advertisements that create a personalized experience across all of their devices.
Become part of a global company, join our team in London! Besides its great location, breakfast, lunch, dinner, and snacks are provided daily with Happy Hour on Friday afternoons! Quantcast was honored as a Glassdoor Best Place to Work in 2015 & 2016. To learn more, follow Quantcast on Glassdoor.

Back to top