Senior Browser Engineer (Defensive Automation & Resilience) - Full-time - WW

Seniority: Senior / Staff-level
Team: Platform - Web Automation & Resilience
Reports to: CTO

We build robust, enterprise-grade web data platforms for lawful content analysis and brand protection. We value engineers who can deeply understand browsers, automation frameworks, and detection signals - and who apply that knowledge responsibly to make scraping and automation reliable, observable, and legally compliant at scale.

Role summary

We’re hiring a Senior Browser Engineer - a pragmatic browser wizard who can read and modify browser internals, extend and harden our Playwright-based stack, and build observability and telemetry that helps our automation succeed in real-world sites.

This role focuses on resilience and defensive testing: improving reliability across diverse sites, instrumenting browsers for debugging, building secure custom browser builds and extensions for enterprise integrations, and designing controlled red-team testbeds (with legal sign-off).

● Engineering & Browser Work
○ Maintain and extend Playwright-compatible browser builds and runtime patches (Chromium and/or Firefox) for authorized enterprise use-cases.
○ Implement safe, documented browser instrumentation (tracing, telemetry, synthetic hooks) to improve debugging and reliability of scraping jobs.
○ Build small, audited browser patches or extensions for observability, debugging controls, and enterprise features (e.g., request logging, feature flags, latency injection for testing) while preserving web-platform compatibility.
○ Work with the infra team to build containerized browser worker images and deployment tooling (Docker, Kubernetes, GKE).

● Resilience & Robustness
○ Design and implement reliability patterns: adaptive retries, network-timeout heuristics, fallback strategies, stateful session management, and robust cookie/credential handling.
○ Create and run synthetic testbeds to mimic complex site behaviors (JS-heavy SPA, streaming resources, long-polling websockets) to measure and improve scraper reliability.
○ Instrument and debug issues caused by client-side rendering, dynamic content, and progressive hydration; propose fixes with minimal changes to runtime behavior.

● Defensive/Authorized Testing & Detection
○ Lead and participate in authorized red-team exercises with legal sign-off to measure fragility and detection triggers on target sites where permission exists. ○ Analyze common detection signals (timing, browser metrics, behavioral
heuristics) to detect when clients are being challenged and design defensive flows (e.g., automated fallbacks to API requests, human review, or pausing jobs). ○ Interface with legal/compliance to draft test plans, get approvals, and run limited-scope experiments safely.

● Observability, Telemetry & Tooling
○ Design comprehensive observability for scraping fleets: per-run traces, screenshots-on-failure, network waterfalls, resource timing, and centralized dashboards.
○ Build developer tools (CLI utilities, debugger panels, trace viewers) to accelerate root-cause analysis for flaky runs.
○ Track meaningful KPIs and maintain runbooks for common failure modes.

● Scale & Platform
○ Design scalable worker fleets and job schedulers that enforce per-target concurrency, rate limits and adhere to authorized constraints to avoid accidental overload.
○ Integrate with proxy providers (residential/datacenter) and credential vaults, ensuring secure handling and audit trails.
○ Partner with product and ops to design API/SDKs for business teams to trigger authorized scraping tasks safely.

● Mentorship & Process
○ Mentor junior engineers, conduct code reviews, and contribute to engineering standards around safe browser modifications.
○ Maintain rigorous documentation, reproducible builds, and secure release processes for any browser or extension artifacts.

Must-have qualifications (requirements)

• 5+ years building and shipping browser-related features, automation platforms, or systems that interact with major browsers (Chromium or Firefox).
• Strong practical experience with Playwright and/or Puppeteer and integrating custom browser builds or extensions into an automation stack.
• Hands-on experience reading and modifying browser code or building instrumented browser builds (e.g., building Chromium forks, shipping small patches, or writing native extensions); comfort with codebase and build toolchain.
• Solid systems engineering background: C++ and/or Rust experience (for Chromium/Firefox internals), and high-level language experience (Python/Node/Go) for orchestration layers.
• Deep knowledge of web platform internals: DOM lifecycle, JS engines, resource loading, CSP, cookies, same-origin, and network stack (including HTTP/2, TLS).
• Demonstrated experience implementing observability/telemetry for browsers: tracing, HAR capture, performance timing, and screenshot capture on failure.
• Good understanding of common anti-bot signals and detection mechanisms for defensive purposes: how to detect, monitor, and respond - not for evasion.
• Strong engineering judgment regarding legal and ethical constraints around scraping and third-party content. Comfortable coordinating with legal and ops on safe test plans.
• Experience with container orchestration (Docker, Kubernetes), CI/CD, reproducible builds, and secure credential management (Vault/KMS).
• Excellent communication and documentation skills.

Strong pluses (nice-to-have)

• Prior experience building or maintaining Chromium forks, or large-scale Firefox modifications.
• Published patches, repos, or open-source contributions to browser tooling, Playwright integrations, or developer tooling.
• Familiarity with anti-fraud/bot-detection vendors and enterprise CAPTCHAs (for integration with authorized solving services and for building mitigation flows that fall back to human review).
• Background in security engineering, adversarial testing, or prior authorized red-team work (with clear legal process).
• Experience with high-throughput distributed scraping fleets and optimizing for cost/performance at scale.
• Experience building synthetic test generators that emulate realistic human-like interactions for regression testing