Senior Application Security Engineer

As a Senior Security Engineer on the AppSec Foundations team, you will be instrumental in making secure behavior the default across the Datadog platform. Your focus will be to build scalable, platform-level security controls to enforce production security invariants across our infrastructure and developer workflows.

You will operate at the intersection of distributed systems and security, focusing on enforcing security by construction. This approach eliminates reliance on manual reviews or reactive fixes, enabling engineering teams to move fast without needing specialized security expertise.

A key part of this role involves shaping the implementation of identity, access, and isolation across our systems, including support for next-generation, AI-driven, and agentic workloads. By defining how security is automatically built-in across Datadog’s platform, your work will improve consistency, reduce friction for engineering teams, and enable the company to scale securely as we expand into new technological domains.

What You’ll Do:

• Design and implement secure-by-default platform controls, improving the security of our APIs and services.

• Build and evolve security systems and enforcement layers (e.g., gateways, middleware, policy engines) that operate at scale across distributed systems

• Define and standardize security patterns that can be broadly adopted across services, reducing the need for custom implementations

• Integrate security controls into developer workflows, infrastructure, and platform abstractions to drive high adoption

• Identify recurring security risks and translate them into reusable, enforced platform primitives

• Partner with engineering teams to influence system design and build out security that is embedded early in the development lifecycle

• Contribute to threat modeling and security reviews where needed, with a focus on turning findings into systemic improvements

• Leverage application telemetry (logs, traces, metrics) to assess security posture and drive improvements

Who You Are:

• You have a strong background in software engineering and experience building distributed systems (Go or Python preferred)

• You have experience designing and implementing security controls or systems (e.g., authentication, authorization, API security, or infrastructure security)

• You have built shared infrastructure, internal platforms, libraries, frameworks, or enforcement mechanisms used by other engineering teams.

• You understand how modern systems handle identity, communication, and t