Horizon3AI
Senior Software Engineer, Browser Automation
$199K–$235K
US, Remote · Remote · Senior · Full-time · Posted Jun 23, 2026
- Experience
- Experience building production software; no number of years stated.
About the job
Own and improve a production-safe browser automation and crawling engine that maps web applications for autonomous penetration testing.
What you'll do
- Build and harden browser-driven crawling for modern web apps, including authentication, SPAs, multi-step flows, and anti-bot defenses.
- Improve crawl coverage, determinism, throughput, and reliability across concurrent browser sessions.
- Balance deterministic automation with selective LLM-based navigation and collaborate on application mapping for the pentesting pipeline.
What they ask for
- Production software experience and deep hands-on browser automation experience with real, non-trivial web applications.
- Strong TypeScript / Node.js skills and familiarity with Chromium internals, Chrome DevTools Protocol, network interception, the DOM, and JS execution contexts.
- Experience handling flaky, stateful JavaScript-heavy apps, including SPA timing, authentication, and anti-automation defenses.
- Distributed/concurrent systems experience, including queues, backpressure, retries, idempotency, and reliable browser sessions at scale.
Nice to have
- Experience with agentic browser frameworks or LLM-in-the-loop automation.
- Web application security, offensive tooling, graph data models, or large-scale crawling experience.
Pay
Base salary: USD $199,000-$235,000 annually
Tools
Playwright, Stagehand, Puppeteer, Selenium, TypeScript, Node.js, Chromium, Chrome DevTools Protocol
AI focus
Apply LLM-driven navigation selectively when deterministic automation is insufficient, accounting for latency, nondeterminism, debuggability, and cost.
Model-written summary · the original posting is authoritative