Staff Security Engineer - Bot & Traffic Defence

Faire•San Francisco, CA

6h•$231,000 - $318,000•Hybrid

About The Position

Our Engineering organization owns the software that makes our marketplace work. Our Bot & Traffic Defence function owns how Faire holds up against automated traffic: scraping, credential abuse, and application-layer DDoS, from the edge through to detection and scoring. We care about good engineering practice and love to write software that is secure, tested, easy to maintain, and can scale to millions of users. We build scalable, reusable frameworks; consult with product teams; listen to the data; and iterate. As a Staff Security Engineer, Bot & Traffic Defence, you will be the first dedicated owner of this domain. You will set the technical direction, build the controls and signals that back it, and establish an ownership model that holds across Security, Platform, service teams, and Anti-Abuse.

Requirements

Hands-on operational ownership of a CDN or edge security platform (Cloudflare, Akamai, Fastly, or AWS CloudFront/WAF/Shield) in production against real adversaries, managed as code rather than clicked through a vendor dashboard.
Experience defending a high-traffic consumer site against scraping and application-layer DDoS, including the part where the attacker shifts vectors a week after your control ships, and the instinct to design for raising attacker cost rather than for a permanent block.
A practical understanding of bot detection signals and where each one fails: TLS and HTTP fingerprinting (JA3/JA4), behavioural signals, mobile device attestation (App Attest, Play Integrity), and challenges, with a real view on the precision and recall trade-off each one carries.
Experience designing distributed rate limiting at layer 7, including the differences between per-IP, per-ASN, per-session, and per-fingerprint keying, when each gets evaded, and how to hold counter state across a fleet without the limiter becoming the bottleneck.
Quantitative rigour in detection work: you can measure a detection's precision and recall, set a false-positive tolerance with the business, and defend a threshold change with data rather than intuition.
A preference for solving traffic and abuse problems with code rather than manual operations, including writing and maintaining internal tooling that on-call engineers depend on mid-incident.
Comfort writing and reviewing code in an OOP language such as Kotlin, Java, Python, or TypeScript, enough to read an unfamiliar service, find where a control is being bypassed, and open the pull request that fixes it.
Working fluency with infrastructure as code and cloud environments (Terraform, AWS or GCP, Kubernetes) sufficient to own a security control plane, and the judgment to know when a Terraform-gated workflow is too slow for an incident and needs a break-glass path with an audit trail.
Experience owning incident response for a live traffic attack, including holding the authority to block traffic under time pressure.
A track record of setting technical direction in an ambiguous domain with no existing owner, and of sequencing work when everything is nominally urgent.
Experience landing a cross-team ownership model without authority, including moving responsibility away from a team that currently holds it and getting other teams to accept obligations they did not ask for.
Comfort delivering primarily through other teams rather than personal throughput.
The ability to put security risk in business terms for executives, translating traffic and abuse metrics into revenue, cost, and reputational exposure.
Clear communication with engineers outside security, describing an attack and its trade-offs without alarmism or unexplained jargon.

Responsibilities

Own the technical strategy and roadmap for bot, scraping, and application-layer DDoS defence end to end, from edge controls through detection and scoring, including revising the strategy where the evidence contradicts it.
Author and tune edge security controls as code: WAF rules, rate limiting policies, and challenge mechanisms, against real adversaries who respond to every change you make.
Build higher-confidence bot and trust signals so that Faire can enforce more aggressively without turning legitimate logged-out buyers away.
Design and operate distributed layer 7 rate limiting, and make the calls on keying, counter state, and where in the stack enforcement belongs.
Make incident response for bot and DDoS events a solved problem: clear paging paths, runbooks a non-specialist on-call can execute at 3am, and observability that answers whether humans are actually being affected.
Lead post-incident reviews on recurring classes of bot incidents so systemic causes surface instead of repeating.
Build the tooling, secure defaults, and playbooks that let service-owning teams protect their own endpoints correctly without you in the loop for every decision.
Land a durable ownership model across Security, Platform, service teams, and Anti-Abuse, where every attack vector has a named owner who has accepted it and it holds without escalation.
Make Faire's bot posture legible to leadership, including a defensible view of residual risk, and force the outstanding business decisions that engineering is currently making by default.