Sr. Backend Engineer - Ad Buying

The ad landscape is unpredictable — traffic spikes, auctions fluctuate, and budgets never sleep. Your team’s mission? Make sure every dollar is spent exactly where and when it should be. It’s like balancing a checkbook on a roller coaster — but with better code and cooler teammates.

We’re looking for a Senior Backend Engineer to join our Ad Buying-Pacing team — the brains behind ensuring every advertising campaign spends efficiently, accurately, and right on time. This squad owns the logic that controls how we bid, how fast we spend, and how we keep performance rock solid across billions of daily auctions.

It’s a mix of math, machine learning, and “how in the world does all this happen in milliseconds?” energy. You’ll be writing systems that talk to some of the biggest streaming and supply-side partners in real time, processing over a terabyte of data and hundreds of thousands of updates per day. This is one of those “under the hood” teams that quietly runs the show — and right now, they’re about to launch a brand-new, in-house pacing algorithm that has serious visibility across leadership. (Translation: your work here gets noticed.)

What You'll Do: 

• Build and maintain backend services that power MNTN’s distributed pacing and ad buying systems.

• Take extreme ownership — spot issues before they become problems, and drive them all the way to done.

• Analyze oceans of data, detect anomalies, and make informed, data-driven improvements.

• Scale microservices that perform beautifully at ridiculous load levels.

• Continuously refine and evolve services for speed, reliability, and maintainability.

• Collaborate across business, project, and ML teams to translate complex logic into systems that just work.

• Raise the bar for engineering quality through mentorship, thoughtful code reviews, and technical leadership.

What You'll Bring:

• 5+ years of experience building distributed systems (preferred Kotlin, python).

• Expertise in non relational & relational databases, including SQL, schema design, indexing, and performance tuning.

• Demonstrated experience with microservices architecture in production environments.

• Comfort working across tech stacks, including systems written in Rust, Python, and/or data platforms like PySpark.

• Familiarity high-throughput messaging systems.

• Practical experience on cloud platforms such as GCP or AWS.

• Strong understanding of Linux/UNIX environments and developer tooling (e.g., Git, CI/CD).

• A product mindset, curious about how your work impacts customers and how systems perform at scale.

• Enthusiastic about using AI tools in your workflow to enhance productivity.

• Big plus if you have any exposure to OpenRTB, DSP, Ads delivery optimizations.