Senior Software Engineer, Demand Bidder, Ad Serving Platform

What does the team work on?

Roku's Ad Serving Team builds and operates the real-time advertising platform that powers all of Roku’s ad monetization across video, display, and native ad formats. Within Ad Serving, the Demand Bidder team owns the high throughput and low latency systems responsible for serving relevant ads for tens of thousands of campaigns through targeting, scoring, bidding, auctions, measurement and more. Every millisecond and every decision carries direct, measurable revenue impact, and the team operates with the high engineering rigor that this demands.

What is the role?

We're hiring a Senior Software Engineer to help scale and evolve this platform. Demand Bidder is a large, high-throughput system driving our next phase of growth. As we onboard a rapid wave of new businesses, we are actively scaling and advancing our architecture — including our pacing engine, scoring/ML engine, and modularizing for agentic development. You'll work alongside a strong team of engineers tackling meaningful technical challenges at scale.

How will I use AI at Roku?

At Roku, we don’t just use AI, we work with it. AI agents and smart tools help power drafts, analysis, and repetitive workflows, while our people bring direction, judgment, and accountability. We’re looking for curious, adaptable builders who can show how they’ve used AI or automation to move faster, raise the bar, and scale their impact.  We value your AI skills if you have built fluency across the agentic engineering toolchain — coding harnesses like Claude Code or Cursor, MCP servers, custom skills, or agent frameworks. And you can describe projects where you shipped real work with these tools. You know how to drive an agent, verify its output, and ramp on an unfamiliar codebase with an agent helping you.

What are the responsibilities of the role?

• Design, build, and contribute to core components of a large-scale, real-time distributed decisioning system with strict latency requirements
• Own features and drive them end-to-end in partnership with product and other engineering teams
• Build a working mental model of a highly distributed, complex production system and make meaningful contributions
• Help identify opportunities to evolve the system and tooling over time
• Partner with engineers and applied scientists working at the intersection of distributed systems and statistical/ML-driven decision-making
• Help diagnose and resolve subtle, often timing- or statistics-related issues in a highly concurrent, multi-region distributed system
• Communicate clearly with both technical and non-technical stakeholders, and collaborate across engineering, product, and business partners
• Be an evangelist for best practices across development, testing, and operations

What experience would help someone be successful in this role at Roku?

• 10+ years of experience designing, building, and operating large-scale, low-latency distributed systems
• Experience owning features or subsystems through design, build, testing, deployment, and iteration based on production feedback
• Ability to ramp into unfamiliar, complex, large codebases and become productive — you enjoy the “figure it out” part of the job as much as the “build it” part
• Comfort contributing to live, business-critical systems without compromising uptime or correctness
• Strong command of Java, with a solid foundation in algorithms, data structures, concurrency/multi-threading, and performance optimization
• Experience with distributed caching, high-throughput messaging/streaming systems, and SQL/NoSQL datastores
• Comfort operating in cloud infrastructure (GCP or AWS) at scale
• Exposure to statistical, control-theory, or ML-driven techniques within production decision-making systems is a plus
• Real-time bidding / ad-tech domain experience is a plus, but experience in adjacent high-stakes, low-latency domains (trading systems, ranking/recommendation, matchmaking, risk/fraud systems) is equally valued
• B.S. or M.S. in Computer Science, Engineering, or equivalent practical experience
• Self-motivated, critical thinker, comfortable operating with some ambiguity
• Low-ego, nonpolitical, and genuinely collaborative
• You've used AI coding assistants (e.g., Claude Code, Cursor, or similar) in real work — deep prior experience isn't required, curiosity is what matters most