Sr Software Engineer, Ads Auctions & Marketplace Optimization

Salary: £60,000 - 100,000 per year

Requirements:

• Around six or more years building production software, with strong systems judgement
• Production experience in Java or another JVM language, or depth in a comparable statically typed language such as C#, C++ or Go, and the appetite to ramp on Java
• Comfort designing and operating distributed systems at scale and low latency
• A solid grounding in maths, algorithms, probability and statistics as applied to real systems
• Demonstrated AI and agentic-tooling fluency, including coding harnesses like Claude Code or Cursor, MCP servers, custom skills, or agent frameworks
• Ability to describe projects where we shipped real work using AI tools
• Ability to drive an agent, verify its output, and ramp on an unfamiliar codebase with agent support
• Ad tech, auctions or marketplace experience is preferred
• Comparable experience on mathematically rigorous or optimisation-heavy problems in another domain is an acceptable alternative

Responsibilities:

• Design and build components of our real-time ad auction and marketplace systems
• Own the multi-objective optimisation at the core of the auction, balancing what advertisers, publishers, viewers, and Roku each want from the same impression
• Own development work end to end, from framing the problem through production rollout
• Build and operate JVM services where latency and reliability are product requirements
• Use probability, statistics and experimentation to test changes before and after launch
• Work with AI tooling as a normal part of how we design, build, test and review
• Explain technical trade-offs clearly to engineering and cross-functional partners

Technologies:

• AI
• C#
• Claude Code
• Cursor
• Support
• JVM
• Java
• MCP
• Roku
• AI Agents
• LESS
• React

More:

We are Roku, the #1 TV streaming platform in the U.S., Canada, and Mexico, and we pioneered streaming to the TV. Our mission is to connect the entire TV ecosystem by helping consumers find the content they love, enabling publishers to build and monetize audiences, and giving advertisers unique ways to engage viewers. Our Ads Auctions and Marketplace Optimization team builds the auction mechanics, pricing and pacing logic, and low-latency systems that power real-time ad clearing and pricing across a platform with more than 100 million active accounts. We are growing our Cambridge hub alongside colleagues in Amsterdam, Austin, San Jose, Ukraine and Uruguay. We offer a fast-paced, collaborative environment, hybrid working with most teams in the office Monday through Thursday and Fridays generally flexible for remote work, and a benefits package that may include healthcare, life, accident, disability, commuter and retirement options, as well as mental health and financial wellness support and time off in accordance with local policies.

last updated 36 week of 2026