# Senior Software Engineer, Anti-Abuse & Security

**Company:** [Replit](https://hotfix.jobs/companies/replit)
**Location:** Foster City, CA
**Role:** Security Engineering
**Salary:** $190k – $240k/yr
**Experience:** 4+ years
**Skills:** Python, TypeScript, SQL, BigQuery, LLMs, Kubernetes, GCP, SAST, Sca, Snyk
**Posted:** 2026-01-12

> Builds AI-powered anti-abuse detection systems using LLMs to combat phishing, cryptomining, and platform exploitation at scale. Requires 4+ years in security engineering with Python/TypeScript and data analysis experience.

## Job Description

## In this role you will…
- 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

## Required skills and experience:
- 4+ 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

## Tools + Tech Stack for this role
- **Languages:** Python, TypeScript, Go, SQL
- **Data:** BigQuery, Hex
- **Detection tools:** Slurper, Netwatch, Stytch (device fingerprint); ClearOut (email reputation)
- **CI/CD Security:** Dependabot, Snyk, SAST/SCA scanners
- **Infrastructure:** GCP, Kubernetes
- **Collaboration:** Linear, Slack, Zendesk (for abuse reports)

## Similar roles

- [Security Engineer - Product](https://hotfix.jobs/jobs/3b4c4dd3-25b2-4d9b-8fb6-43a7a73dd2f8) - Cardless - San Francisco, CA - $190k – $260k/yr
- [Senior Application Security Engineer](https://hotfix.jobs/jobs/45402dbe-ee8f-4a25-9817-c293c712505a) - Apollo - Remote - $190k – $273k/yr
- [Senior Software Engineer - Security](https://hotfix.jobs/jobs/e3185b76-5a92-4a24-956c-5a19fd20d75d) - Skydio - San Mateo, CA - $190k – $250k/yr
- [Senior Security Engineer, Application & Platform Security](https://hotfix.jobs/jobs/935a9604-4c7b-48d9-a08b-cb94b61fb298) - Sentry - San Francisco, CA - $190k – $280k/yr
- [Senior Infrastructure Security Engineer](https://hotfix.jobs/jobs/f7e815e7-b9b7-4df4-a889-e6d7d1e91808) - Dropbox - Remote - $190k – $290k/yr

**Apply:** https://hotfix.jobs/jobs/af883f53-3346-4cc3-827e-3e9664ff95c3
**Canonical:** https://hotfix.jobs/jobs/af883f53-3346-4cc3-827e-3e9664ff95c3