Senior Software Engineer - Marketplace Quality Engineering

The Trade Desk is a global technology company with a mission to create a better, more open internet for everyone through principled, intelligent advertising. Handling over 1 trillion queries per day, our platform operates at an unprecedented scale. We have also built something even stronger and more valuable: an award-winning culture based on trust, ownership, empathy, and collaboration. We value the unique experiences and perspectives that each person brings to The Trade Desk, and we are committed to fostering inclusive spaces where everyone can bring their authentic selves to work every day.

Do you have a passion for solving hard problems at scale? Are you eager to join a dynamic, globally- connected team where your contributions will make a meaningful difference in building a better media ecosystem? Come and see why Fortune magazine consistently ranks The Trade Desk among the best small- to medium-sized workplaces globally.

The Team: Marketplace Quality Engineering:

Every second, our bidder evaluates millions of ad opportunities across thousands of publishers and supply paths. Not all of that supply is created equal - some of it is duplicated, some is structurally inaccessible, and some degrades advertiser outcomes. The Marketplace Quality Engineering team exists to make sure our platform is buying the right impressions, not just more impressions.

We own the systems that assess, measure, and optimize supply quality across the programmatic ecosystem. Our work spans deduplication, supply path analysis, quality modeling, and the tooling that turns those signals into decisions at bid time. The problems are technically deep - think identity resolution across fragmented supply chains, statistical modeling to separate signal from noise, and real-time decisioning at platform scale - and they have direct, measurable impact on both advertiser outcomes and platform economics.

This is not theoretical work. When we ship a model update, spend distribution across the platform shifts. Our engineering decisions translate directly into tens of millions of dollars of measurable business impact. If you want to build systems where what you ship visibly matters, this is the team.

You will work with C# / .NET as a core strength, alongside Python and SQL where data and automation need it, and partner closely with product, data, and platform teams across time zones.

Who you are:

Our culture runs deeper than having fun together (though we do that well, too). We take pride in our engineers being trust-builders, generous givers, scrappy problem solvers, and gritty pursuers of excellence. You do not need to meet every requirement below, but people who meet most of them tend to thrive in this role:

- You are comfortable working on an agile, distributed team across time zones and continents.

- You communicate effectively with both technical and non-technical audiences.

- You have a solid grasp of computer science and engineering fundamentals.

- You have strong experience with distributed systems and data-heavy backend work (services, pipelines, or both).

- You are proficient in C# / .NET.

- You are productive with modern development tools: Visual Studio, Visual Studio Code, Rider, and Git.

- You bring 7+ years of software development or engineering experience.

Nice to have (not required): GraphQL or REST API design, large-scale data processing frameworks (e.g. Apache Spark), workflow orchestration tools (e.g. Apache Airflow), schema-based data serialization, Kubernetes, Kafka, database engines (Microsoft SQL Server, PostgreSQL, Aerospike, Vertica, Redis), microservices, Python for data work or automation, and experience working across large codebases with multiple teams.

A wide range of technical opportunities is one of the best parts of engineering at The Trade Desk, which is why we do not expect you to know every technology we use on day one. What matters is that you learn quickly and solve complex problems with the right tools. What you know today matters less than how well you learn, adapt, and innovate. We are not looking for people who already have all the answers - we want engineers who can invent answers no one has thought of yet and frame the questions we have not yet asked.