Build and operate AI-powered abuse detection systems that defend Replit's platform from phishing, cryptomining, LLM token farming, and other attacks. Own end-to-end detection, investigation, and automated response across millions of daily actions.
250k – 315k
Hybrid8+ YOESecurity Engineering
About the role
Responsibilities
Design and implement LLM guardrails that detect abuse scenarios in AI-generated code and agent interactions
Build AI-powered detection systems that use LLMs to identify malicious patterns, classify threats, and automate response decisions
Build and operate abuse detection systems that identify phishing, cryptomining, account takeover, and financial fraud across millions of daily user actions
Design automated response mechanisms that enforce platform policies without manual intervention
Own the full abuse response lifecycle: detection, investigation, enforcement, and handling appeals alongside Support and Legal
Analyze attack patterns using BigQuery and Hex, turning investigation findings into new detection rules
Maintain and extend internal detection tools (Slurper, Netwatch) that continuously monitor user activity
Integrate and tune security scanners (SAST, SCA) in CI pipelines with tight performance SLAs
Track abuse trends, measure detection effectiveness, and adapt defenses as attack patterns evolve
Requirements
8+ years of experience in security engineering, anti-abuse, trust & safety, or fraud detection
Strong programming skills in Python and/or TypeScript for building detection systems and automation
Experience with SQL and data analysis at scale (BigQuery, Snowflake, or similar)
Experience building or fine-tuning ML/LLM-based classifiers for security or abuse detection
Familiarity with prompt injection, jailbreaking, and other LLM-specific attack vectors
Ability to investigate complex abuse patterns and translate findings into automated defenses
Familiarity with common attack patterns: phishing infrastructure, account takeover, credential stuffing, resource abuse
Clear communication skills for working across Security, Support, Legal, and Engineering teams
Nice to Have
Experience at a platform company dealing with user-generated content or compute abuse (hosting providers, cloud platforms, developer tools)
Background in fraud detection, payment abuse, or financial crime
Familiarity with device fingerprinting, IP reputation, and email validation services
Experience with CI/CD security tooling (SAST, SCA, Dependabot, Snyk)
Knowledge of container security, Linux internals, or cloud infrastructure (GCP preferred)
Prior work with abuse reporting pipelines, trust & safety tooling, or content moderation systems
Build and operate AI-powered fraud/abuse detection systems defending Replit's platform from phishing, cryptomining, account takeover, and LLM abuse. Requires 8+ years in security/anti-abuse, Python/TypeScript, SQL at scale, and ML/LLM classifier experience.
250k – 315k
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Build and operate AI-powered abuse detection systems at Replit to combat phishing, cryptomining, prompt injection, and other platform abuse at scale. Requires 8+ years in security/anti-abuse and strong Python/TypeScript + SQL skills.
250k – 315k
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