Staff Software Engineer (Anti-Abuse & Security)

Join Replit, a leading AI-native platform, as a Staff Software Engineer in the Anti-Abuse & Security team. In this role, you will be at the forefront of defending the platform from exploitation, detecting and shutting down phishing deployments, preventing cryptomining, and stopping LLM token farming. You will work on unique problems related to AI-generated code and use LLMs as a defensive tool against abuse. This is a hands-on position where you will own problems end-to-end, from identifying emerging abuse patterns to shipping the systems that stop them at scale.

• 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.
• Own the full abuse response lifecycle: detection, investigation, enforcement, and handling appeals alongside Support and Legal.
• Familiarity with common attack patterns: phishing infrastructure, account takeover, credential stuffing, resource abuse
• Strong programming skills in Python and/or TypeScript for building detection systems and automation
• Clear communication skills for working across Security, Support, Legal, and Engineering teams
• 8+ years of experience in security engineering, anti-abuse, trust & safety, or fraud detection
• Ability to investigate complex abuse patterns and translate findings into automated defenses
• 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
• 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
• Experience with CI/CD security tooling (SAST, SCA, Dependabot, Snyk)
• Familiarity with device fingerprinting, IP reputation, and email validation services
• Knowledge of container security, Linux internals, or cloud infrastructure (GCP preferred)
• Prior work with abuse reporting pipelines, trust & safety tooling, or content moderation systems