Engineering Manager, Site Defense

Reddit's Transport and Site Defense teams build and operate foundational infrastructure behind one of the largest sites in the world. These teams own how requests enter Reddit, how services discover and talk to each other, how traffic moves across clusters and clouds, and how Reddit protects itself from DDoS attacks, scrapers, bots, and other undesired traffic.

We are looking for an experienced Engineering Manager to lead and grow the Site Defense teams. This is a high-impact role for a manager who can guide senior engineers, make strong technical and organizational tradeoffs, and help Reddit scale critical traffic and defense platforms while keeping the site available.

How You'll Have Impact: 

• Complete Reddit's migration from Fastly to Cloudflare, including high-traffic properties such as reddit.com, media endpoints, Ads endpoints, e.reddit.com/gql-fed, devvit.reddit.com, and long-tail CDN traffic.
• Make Portal Transporter the predominant service discovery platform for Reddit, moving toward broad gRPC/xDS adoption and reducing fragmented service discovery.
• Migrate high-volume Thrift traffic to gRPC through TGRPC while preserving reliability, customer trust, and migration velocity.
• Reduce data transfer and cross-cluster networking costs through smarter routing, service discovery, and infrastructure standardization.
• Expand Site Defense coverage across post-CDN traffic, including TAC, RLS, TRS, Recaptcha, edge challenges, device attestation, IP reputation, and bot context.
• Deliver the Site Defense Platform and ML-at-ingress direction in a way that improves defense effectiveness while controlling false positives and preserving user experience.
• Operate merged Transport and Site Defense on-call responsibilities while protecting team focus, improving runbooks, cross-training engineers, and clarifying ownership boundaries with Site Experience SRE.
• Maintain high availability and low latency while performing large migrations on systems that sit directly in Reddit's request path.

What you'll do: 

• Lead, hire, onboard, and develop a high-caliber team of infrastructure engineers across Transport and Site Defense.
• Partner with senior ICs to define technical strategy for global traffic, edge/CDN, service discovery, gRPC datapath, rate limiting, site defense, and bot detection infrastructure.
• Drive multi-quarter execution on high-risk platform migrations, including CDN migration, inter-cluster load balancer adoption, Thrift to GRPC migration, and Site Defense Platform expansion.
• Establish clear priority frameworks that balance KTLO, roadmap commitments, incidents, business-critical migrations, and cross-functional asks.
• Build and maintain a healthy operational model for critical infrastructure, including on-c