Fraud & Abuse Engineer · Anti-Fraud, Account Security & PKI

Sole architect and lead engineer of the authentication, identity, and certificate- issuance platform at a top-10 global certificate authority. I design the distributed services, scale issuance through 10x growth, and, because attackers come with the territory, run the fraud and abuse defense too.

• ▸ Sole architect of the company-wide authentication and identity platform (OAuth2, OIDC, SAML, session-based flows, external IdP integrations) serving tens of thousands of daily users; scaled the backend through 10× growth in TLS, code signing, and identity certificate issuance.
• ▸ Distributed-systems work: extracted authentication into its own service with cross-service sessions, built multi-perspective certificate validation (MPIC) with quorum across vantage points, and designed the API servers, async workers, and audit pipelines around them.
• ▸ Performance at scale: cut backend latency up to 5× and fixed slow API paths by eliminating N+1 queries, a hot-path regex, and a write storm, and by reworking batch polling into per-record jobs.
• ▸ Correctness in money and state: idempotent billing, atomic multi-step writes, and APIs that stay backward-compatible as they grow.
• ▸ Fraud, security & abuse: shut down months-long attacker reconnaissance before exploitation; bot defense at 1,000+ fake signups/day incl. CAPTCHA-farm countermeasures; stopped a $2,500/day SMS pumping attack in 4 days ($0 losses since); and defeated a persistent session hijacker who survived password resets, 2FA resets, and endpoint forensics.
• ▸ Also built insider-threat and identity-theft detection, pairing LLM-augmented pattern matching with human-led forensics to go from detection to mitigation in minutes, not days.

• Ruby on Rails
• PostgreSQL
• Redis
• OAuth2
• OIDC
• SAML
• PKI
• Sidekiq
• AWS

Early engineer on a 5-person team building a consumer product with ~1k DAU (joined as an intern in Aug 2022). Owned end-to-end features across the Rails stack and led incident response. Final 5 months were a contract wind-down with gradual transition of responsibilities while ramping up at SSL.com.

• ▸ Closed authorization flaws surfaced in a live penetration test, including a broken access control that let the tester join private two-person chats as a third participant; led incident response against advanced attackers.
• ▸ Reduced backend latency by up to 5× through query optimization, indexing, and caching.
• ▸ Improved user retention by 15% through targeted performance and product improvements.
• ▸ Shipped 4 major product features in 12 months, supporting multiple product pivots.

• Ruby on Rails
• PostgreSQL
• Redis
• JavaScript
• Stimulus
• AWS

Built and managed automated hedging strategies across multiple brokers, markets, and financial instruments. Risk modeling under adversarial market conditions is the same discipline as fraud detection: spotting anomalies early, capping losses, and acting fast when the numbers move against you.

• ▸ Reduced hedging costs by up to 35% through strategy optimization and execution improvements.
• ▸ Managed a large leveraged portfolio with rigorous risk control and capital efficiency.
• ▸ Self-taught Ruby in parallel during this role, transitioning to engineering by mid-2022.

• Python
• C++
• SQL