Senior Backend Engineer

We are looking for a highly experienced backend engineer to lead the architecture, reliability, and evolution of Lokker's scanning systems.

This person will own the technology that enables Lokker to scan websites and public-facing infrastructure at scale, observe complex marketing and advertising stacks, detect browser-side ingress and egress data flows, and produce high-confidence intelligence even when sites and servers behave differently based on geography, user agent, consent state, bot detection, server-side rules, or other runtime conditions.

This is a deep technical role for someone who understands low-level systems, distributed infrastructure, browser automation, networking, performance, and adversarial web environments. The right person will help make Lokker's scanner more accurate, more efficient, more cost-effective, and more resilient as the web becomes harder to observe.

What You'll Own

• Designing and maintaining scalable backend systems that power high-volume website and public-facing infrastructure scanning
• Improving scan accuracy across complex web environments, including dynamic JavaScript-heavy sites, tag managers, consent banners, personalization platforms, and marketing/adtech stacks
• Hardening scanner behavior against bot detection, rate limiting, server-side filtering, WAFs, CDNs, fraud-prevention systems, and other mechanisms that may alter or block scan results
• Building scanning strategies that operate reliably across many geographies, network conditions, browser configurations, consent states, and infrastructure paths
• Reducing infrastructure cost while improving throughput, resilience, and data quality
• Expanding distributed scanning capabilities, including the ability to scan from many locations in parallel
• Developing new approaches for observing scripts, pixels, cookies, network calls, SDK/API activity, ingress and egress behavior, and browser-side data leakage
• Owning the quality, reliability, and future-readiness of the scanner as a core Lokker platform capability

What We're Looking For

• Senior/staff-level experience building backend, infrastructure, systems, or low-level engineering systems, with ownership of complex production systems at scale
• Experience building production systems in one or more languages such as Go, Rust, TypeScript/Node.js, C++, or similar
• Deep experience with distributed systems, networking, concurrency, queues, orchestration, and high-scale backend services
• Strong understanding of browser behavior, HTTP, TLS, DNS, proxies, CDNs, WAFs, bot detection, fingerprinting, and web application delivery
• Experience with browser automation, headless browsers, crawlers, scanners, synthetic monitoring, scraping infrastructure, or similar technologies
• Ability to reason about how websites and public-facing infrastructure behave differently across geography, device, user agent, consent state, session state, and bot-detection posture
• Strong instincts around reliability, observability, performance, cost optimization, and operational excellence
• Ability to take ownership of a mission-critical system and improve it with a high degree of autonomy

Bonus Experience

• Building large-scale crawlers, scanners, synthetic browsers, or web intelligence systems
• Anti-bot detection, browser fingerprinting, proxy networks, or adversarial web environments
• Privacy technology, security scanning, web application security, or client-side JavaScript security
• Marketing/adtech ecosystems such as Google Tag Manager, Meta Pixel, TikTok Pixel, GA4, consent mode, CDPs, CMPs, and personalization platforms
• Multi-region infrastructure, distributed job execution, cloud cost optimization, or edge-based scanning
• Data quality systems, anomaly detection, scan validation, or confidence scoring