Lead Senior Software Engineer - Platform Security

The Trade Desk is a global technology company and the world’s leading independent platform for digital advertising, with nearly 4,000 employees across more than 30 offices. Our technology helps advertisers reach the right audiences across the open internet — from streaming TV and podcasts to mobile apps, news, and more.

Advertising powers the content people love. By making it more transparent, effective, and responsible, we help support trusted journalism, quality entertainment, and creators worldwide. The world’s brands and agencies rely on us to reach their customers and grow their businesses responsibly.

The scale of our platform brings unique technical challenges — from processing massive datasets in real time to building systems that operate reliably on a global scale. When you work here, your impact is worldwide. We welcome diverse perspectives, encourage curiosity, and build teams that learn from one another. If you’re driven to solve meaningful challenges, we’d love to meet you.

What we do

Our Software Engineers are end-to-end owners who will participate in all aspects of designing, building, and delivering data-focused products for our stakeholders.

At The Trade Desk we believe that each opportunity to engage with all internal and external stakeholders, is unique. This means y ou will have the opportunity, based on your interests and background, to work on large-scale distributed systems coordinating thousands of servers in cloud and physical data centers around the world, petabyte-scale data challenges, machine learning, advanced visualizations, and interactive user interfaces – to name a few.

Our system performs all day, every day serving global traffic. It’s important we focus on quality at scale in an agile environment that is based on collaboration, ownership, and trust. Our software engineering teams fully own their charter to work on long term roadmaps while enhancing existing features or tools and continuously gaining efficiency.

About the Team:

• The Platform Security team builds foundational systems that enable secure, reliable operation of The Trade Desk at scale. We focus on making security resilient, developer‑friendly, and deeply integrated into the platform.
• Our team builds and operates critical services including:

Authentication and authorization for users and services

Workload identity (SPIFFE / SPIRE‑based)

Secrets and certificate management

Security health monitoring and risk mitigation

Golden images, just‑in‑time access, and secure shared libraries

We partner with teams across the company to deliver tools, libraries, and frameworks that run across Kubernetes, cloud environments (Azure, AWS, Aliyun), and on‑prem infrastructure, supporting a global fleet of 15,000+ machines.

About the Role:

• As a Lead / Senior Software Engineer on Platform Security, you will serve as a technical leader and end‑to‑end owner for security‑critical systems that operate at massive scale.
• This role sits at the intersection of software engineering, reliability, and security. You will lead the design and evolution of core security platforms, drive complex initiatives across teams, and raise the bar for how security is built and operated across The Trade Desk. You will manage a small team of Engineers to include leading technical direction, mentorship, and ownership.

We are a global team with different backgrounds, experiences and perspectives. To complement this team, you will welcome ideas that are different from your own and be well-versed in building from common ground to value, seek out, and foster invisible and visible dimensions of diversity.

What You’ll Do:

Lead the design, implementation, and long‑term evolution of large‑scale security services, from architecture through production operations

Own complex, cross‑cutting initiatives spanning authentication, authorization, identity, and secure access

Make and influence architectural decisions that balance security, reliability, scalability, and developer experience

Drive high‑quality engineering practices, including testing, observability, operational readiness, and incident response

Build and maintain shared libraries and frameworks that standardize authentication, authorization, and security best practices across the company

Partner closely with engineers, SREs, and stakeholders across teams to deliver secure‑by‑default platforms

Mentor and guide other engineers through code reviews, design discussions, and technical leadership

Participate in on‑call rotations and lead incident response for security‑critical systems

Help shape future‑looking initiatives, including AI‑driven systems that reason about security posture, model architecture, and surface risk automatically

This role requires comfort operating in ambiguity and driving outcomes that impact the broader platform.

Who you are:

Our culture is much deeper than just 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 have to meet all the requirements below, but we believe that people who meet most of them will have a higher likelihood of succeeding in this role:

7+ years of established experience in a high scale environment that values infrastructure as code capabilities

Previous Lead experience is desired in this role

Significant professional experience building and operating production systems using an object‑oriented language such as C#, Java, C++, or similar

Proven experience designing and delivering distributed systems at scale

Strong experience deploying and operating services using infrastructure‑as‑code and automated deployment pipelines

Deep understanding of system reliability, observability, and operational excellence

Experience leading technical design and influencing architecture across teams

Strong communication and collaboration skills, with a track record of mentoring other engineers

You have a Bachelor’s/Master’s level degree in a computer-science or relevant engineering related field or equivalent experience. Not everyone has the same level of access to opportunities. What is most important to us is what and how you can contribute, which is why our consideration is not limited by the level of education you have.

Nice to Have Qualifications:

Experience designing or operating identity and access management (IAM) systems

Familiarity with Kubernetes, cloud platforms, or hybrid infrastructure at scale

Background in security engineering or site reliability engineering

Interest in applying automation or AI to improve security posture and resilience

Variety of technical opportunity is one of the best things about working at The Trade Desk as a software engineer which is why we do not expect you to know every technology we use when you start. What we care about is that you can learn quickly and find solutions to complex problems using the optimum tools for the job. What you know is less important than how well you learn and innovate. We don't need engineers who know all the answers; we need engineers who can invent the answers no one has thought of yet, to the questions yet to be asked.

The Trade Desk does not accept unsolicited resumes from search firm recruiters. Fees will not be paid in the event a candidate submitted by a recruiter without an agreement in place is hired; such resumes will be deemed the sole property of The Trade Desk. The Trade Desk is an equal opportunity employer. All aspects of employment will be based on merit, competence, performance, and business needs. We do not discriminate on the basis of race, color, religion, marital status, age, national origin, ancestry, physical or mental disability, medical condition, pregnancy, genetic information, gender, sexual orientation, gender identity or expression, veteran status, or any other status protected under federal, state