Senior Software Engineer - AdTech Bidding Platform / Traffic Shaping Specialist

What You'll Do:
Every ad request that hits our exchange runs through a real-time auction: a bidder decides, in milliseconds, whether to ask our demand partners to bid. Much of the traffic doesn’t get bid on, wasting load on both sides. Your job is to make the system smarter about what to send where.
That means you'll work across the whole stack of a live, high-throughput ad exchange: the Node.js bidder making the real-time decisions, the data pipeline that captures what happened, the SQL that turns billions of events into answers, and the machine-learning models that predict which traffic is worth sending. Few engineering roles let one person see a problem from the hot path to the model and back. This one does.
We're hiring for curiosity, not a checklist. You will not have done all of this before. We care that you learn fast, reason from first principles, and want to understand why a system behaves the way it does.
This role expects AI fluency. Directing AI tools well is core to how we work here. A lot of what we build, from data exploration to model code, is done by steering AI and rigorously checking its output. If that's already how you operate, you'll fit right in. If it's not, this isn't the role for you.

This role will be based in the Bellevue, WA office. Our team follows a hybrid schedule working in-office three days a week and remotely for the rest. This is an exempt position.

Each day can be different here at Nexxen, but some of the things you can expect to be doing daily are:

• The real-time bidder (Node.js) that decides which requests to forward to demand partners, and the throttling layer that acts on those decisions with near-zero latency.

• The job that aggregates traffic performance and produces the throttle layer — the bridge between our analytics and the live bidder.

• Data at scale: SQL over billions of bid requests and impressions to feed our research

• Applied machine learning: gradient-boosted models with interpretability to rank which request features predict a bid, then turning those findings into real-time rules the bidder can use.

What You'll Bring

• Are a strong generalist, comfortable being dropped into an unfamiliar system and figuring it out.

• Can write and reason about production code, with careful attention to performance and correctness.

• Have expertise in at least one backend programming language and distributed systems.

• Are fluent in SQL, or eager to become fluent, and like working with large datasets.

• Ask "why is this like this?" and keep pulling the thread until it makes sense.

• Have experience with AdTech / RTB, real-time or low-latency systems, columnar databases, A/B testing, or ML tooling. Not all of these are required, but one or two would give you a great head start.

• Can work fluently with AI coding tools. Use AI assistants (Claude Code, Copilot, ChatGPT, or similar) as a serious part of how you build — not to paste answers, but to direct the work, review what comes back critically, and move faster across unfamiliar territory than you could alone.
  In support of pay transparency and equity, the minimum and maximum full-time annual base salary for this role is $175,000 - $200,000 the time of posting, with the potential of an incentive or bonus. While this is our reasonable expectation this is not a guarantee of compensation or salary, actual compensation is influenced by a wide range of factors including but not limited to skill set, level of experience, education, certifications, responsibility, and geographic location. Candidates hired to work in other locations will be subject to the pay range associated with that location. We offer a variety of benefits, including medical, dental, vision, disability insurance, 401(k), EAP, parental leave, unlimited vacation, and company-paid holidays. The specific programs and options available will vary depending on the state, start date, and employment type. Our Talent Acquisition team will be happy to answer any questions you may have.
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