Lead Senior Software Engineer - Platform Security

The Trade Desk•New York, NY

3h•$124,900 - $228,900•Hybrid

About The Position

The Trade Desk is a global technology company and the world’s leading independent platform for digital advertising. Our technology helps advertisers reach the right audiences across the open internet. 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. 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 you 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 not manage people, but you will lead through 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. This role requires comfort operating in ambiguity and driving outcomes that impact the broader platform.

Requirements

7+ years of established experience in a high scale environment that values infrastructure as code capabilities
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
A Bachelor’s/Master’s level degree in a computer-science or relevant engineering related field or equivalent experience.

Nice To Haves

Previous Lead experience is desired in this role
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

Responsibilities

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

Benefits

Comprehensive healthcare (medical, dental, and vision) with premiums paid in full for employees and dependents
Retirement benefits such as a 401k plan and company match
Short and long-term disability coverage
Basic life insurance
Well-being benefits
Reimbursement for certain tuition expenses
Parental leave
Sick time of 1 hour per 30 hours worked
Vacation time for full-time employees up to 120 hours thru the first year and 160 hours thereafter
Around 13 paid holidays per year
Employees can also purchase The Trade Desk stock at a discount through The Trade Desk’s Employee Stock Purchase Plan.