Sr Software Engineer - Backend API Platform

Ventura OS is a new Smart TV operating system being built inside The Trade Desk, the world's leading independent platform for digital advertising. Where the wider company runs a global-scale DSP, Ventura is closer to a startup inside it: a small team, direct influence over product direction, and a real OS shipping to real devices in real living rooms.

We're deliberately building the CTV supply chain differently: more efficient for advertisers and publishers, more relevant for viewers, and more transparent end-to-end. The backend that powers all of it is being built now, and API Platform sits at the center of it.

The API Platform team is the front door to Ventura: every boot, every sign-in, and every API call from a TV in the wild passes through us. That makes us the layer the rest of Ventura builds on. We own the APIs the OS calls as it starts up and runs, the identity provider that authenticates each device and user, the portals operators and partners work through, and the pipelines that carry ads and monetization data out to the wider TTD platform.

You'll be an end-to-end owner of the systems this team runs, designing, building, and operating them in production while setting the standards other Ventura teams inherit. This role sits at the intersection of API design, identity engineering, and platform work: the problem space spans OAuth and OIDC flows, device attestation, and the authorization model that scopes every request to the right partner, user, and device. You'll also design under a constraint most API work doesn't have: you can't force an upgrade on a TV in someone's living room, so every API decision is close to permanent. Scale, reliability, and security all have to be true at the same time. There's no room to trade one against the others.

In addition to the core responsibilities of our backend engineers, you will share ownership of:

• Designing parts of the API layer the Ventura platform - the identity model, the API surface, and the developer platform other teams ship on.

• The identity and access model for the OS: authentication, session, device, entitlement, and the multi-tenant authorization that scopes every request to the right partner, user, and device.
• Design how partners and OEMs safely self-serve on Ventura: the authorization boundaries, the audit trails, and the identity surfaces that make it work at scale.
• The shared platform every Ventura team builds on: the testing, rollout, and observability infrastructure that lets other engineers change production safely. When it works, everyone ships faster together. When it breaks, they all break at once.
• The multiple user-facing web portals we ship, and the platform they all run on: auth, navigation, hosting, telemetry, and deployments, solved once for every other Ventura team.
• The monetization surface: the APIs and pipelines that carry ads data between the OS, the ad server, and the wider TTD platform. This is the layer Ventura's revenue actually flows through.
• Set the developer-experience standards other Ventura teams inherit: the shared libraries, the paved paths, and the tooling that make good engineering the path of least resistance. Your customers here aren't just our users; they're the other engineers on Ventura who build on top of you, and the standards you set become how the whole org builds.
• The operational excellence of every service the platform runs: observability, SLOs, on-call, and leading incident response when production is on the line.

One of the best things about working here is the variety of technical opportunities. We don't expect you to know every technology we use from day one. What matters most is that you can learn quickly and solve complex problems using the best tool for the job. What you know is less important than how well you adapt, innovate, and think critically.

We're not looking for engineers who know all the answers. We're looking for engineers who can invent the answers no one has thought of yet, to the questions yet to be asked.

Culture matters. Ventura is a small, high-impact team inside The Trade Desk, and we take pride in our engineers being trust-builders, generous givers, scrappy problem solvers, and gritty pursuers of excellence.

You don't have to meet every requirement below, but if you check most of these boxes, you're likely to thrive in this role.

• Extensive experience designing and operating user-facing APIs in production: the kind that can scale to millions of end users, where reliability and performance are non-negotiable.
• Background in identity and access management: session, device, entitlement, and multi-tenant authorization models, and the discipline required to get them right.
• Hands-on experience with API tooling: contract testing, versioning, and safe rollout and migration patterns across many consumers, including the backwards-compatibility discipline needed when you can't assume every consumer will upgrade on your schedule.
• Track record of end-to-end ownership: significant, self-directed contributions to production services from design through operation, not just feature work.
• Experience owning a shared platform that other engineering teams build on: codifying standards, running paved paths, and helping partner teams adopt them without disrupting delivery.
• Strong programming skills in a modern statically typed backend language.
• Solid understanding of both relational and NoSQL data stores, and how to model tenant-scoped data safely.
• Deep understanding of system reliability, observability, and operational excellence: SLOs, tracing, structured logging, and on-call rigor for user-facing production services.
• Track record of leading technical design and influencing architecture across teams, and mentoring engineers through code and design review.
• Strong communication skills with both engineers and non-technical stakeholders, and comfort scoping and sequencing work in ambiguity.
• 6+ years of software engineering experience, with meaningful time spent on backend platforms, APIs, or identity systems. We care more about what you can contribute than the level of education you have, whether that's a Bachelor's or Master's in Computer Science, a related field, or equivalent experience.

• Experience building production services in Node.js and TypeScript, which much of our API surface runs on.
• Strong experience running always-on services on Kubernetes and AWS at scale.
• Experience with a production OIDC identity provider (Keycloak or similar).
• Experience with device-attestation or public-key device-identity flows (e.g. SPIFFE, mTLS, hardware-root-of-trust patterns).
• Familiarity with event-driven systems for asynchronous telemetry, audit, or ad pipelines.
• Background in Smart TV, OTT, CTV, or any API layer that backs a hardware fleet or a consumer-facing OS.