Advertising at Amazon is a fast-growing, multi-billion dollar business that spans across desktop, mobile and connected devices; encompasses ads on Amazon and a vast network of hundreds of thousands of third party publishers; and extends worldwide. Traffic Quality, within Amazon Advertising, builds technology to detect invalid traffic (IVT) and ensure that Advertiser spend worldwide is directed towards human audiences and protected from ad fraud. As the Security engineering team within Traffic Quality, we research programmatic advertising risk landscapes to build an understanding of existing and emergent threats. We build specialized techniques to detect and mitigate these threats, contributing to a robust Traffic Quality platform that is a bedrock of advertiser trust and saves hundreds of millions of dollars in ad spend that would otherwise be lost to IVT. The Security Engineering team is responsible for: (a) Targeted threat hunting, including on the dark web, to consistently stay updated on modus operandi and risks associated with advertising fraud, (b) Building sophisticated mitigation techniques through reverse engineering known software, identifying network layer signatures, and conceiving client-side scripting methods, and, (c) Collaborating with security teams across Amazon for sharing intelligence and devising durable detection techniques. As a Senior Security Engineer in the team, you are passionate about unraveling ad fraud tactics utilizing a diversity of highly specialized skills in reverse-engineering, deep packet inspection of network traffic, understanding of network security, operating systems and browser architectures. You accomplish your tasks by applying expert level knowledge to tools to understand not only what a particular piece of malware for perpetrating ad fraud can do but also how it does it. You work with internal security teams to identify and mitigate botnets, as well as leverage the ethical hacking community to obtain standard modus operandi, source code and tactics used by malware and botnets. The role requires influencing leaders across the company to improve our security bar and protect advertiser trust. A Senior Security Engineer also works with other product and security teams to proactively identify problems and suggest approaches to solve them. Given the high level of ambiguity in the advertising fraud space, and the need to prepare for unknown unknowns, your creativity, judgement and bias for action will all be key ingredients towards delivering the right results for advertising customers. We are open to hiring candidates to work out of one of the following locations: London, GBR