Senior JavaScript Engineer

HUMAN’s Bot Defender is a market leading product designed to safeguard online platforms and digital assets from automated bot attacks. At HUMAN, our Sensor team is at the forefront of protecting online platforms by distinguishing real users from sophisticated bots. Our JavaScript-based sensor is a critical component of HUMAN’s detection capabilities, gathering high-fidelity signals from browsers and devices to help secure digital ecosystems at scale. We are seeking an experienced engineer to join the Sensor team in pushing the boundaries of real-time, client side (JS) and backend development. Join us and be an essential part of the team that powers the intelligence behind HUMAN’s defense against online threats — helping to keep the internet human! What you'll do: - Drive the design, development, and optimization of advanced JavaScript techniques to collect signals (user behavior, device characteristics, browser APIs) securely and efficiently. - Own the full code lifecycle: architecture, development, deployment, monitoring, and continuous improvement. - Collaborate closely with Product, Research, Security, and Engineering teams to align technical execution with broader product goals. Who you are: - 4+ years of hands-on software development experience, with deep expertise in vanilla JavaScript and browser internals. - Strong understanding of web security concepts, browser APIs, and the nuances of cross-platform development. - A JavaScript enthusiast who enjoys being hands-on: reviewing code, setting architecture and contributing to complex solutions. - Experience with typed backend languages (e.g., Go, Java). - Excellent communication and collaboration skills, with the ability to work effectively across disciplines. - Passionate about performance, security, and crafting elegant technical solutions. Nice to have: - Familiarity with content delivery networks (CDNs) and large-scale deployment strategies. - Background in cybersecurity, bot mitigation, or fraud prevention technologies. About HUMAN Security HUMAN was founded in a Brooklyn sci-fi bookstore with a hacker mindset and the lofty mission of making the internet safer by putting humans first. Today, our Human Defense Platform safeguards enterprises from sophisticated bots, fraud, and account abuse, verifying the humanity of more than 20 trillion interactions per week for the world’s biggest brands and internet platforms. HUMAN is an equal opportunity workplace dedicated to protecting the internet's integrity for everyone. We believe in putting people first, embracing diversity of thought from our global teams, and welcoming all individuals to share their unique experiences as we fight cybercrime together. We support our Humans with a comprehensive total rewards package for personal and professional development, including well-being and learning stipends, flexible work options, and dedicated time off. While our HQ is in NYC, we have teams worldwide. HUMAN is growing fast, and there’s never been a more meaningful time to join us. If you thrive on solving complex problems and want to help shape the future of cybersecurity, join us as we build a safer, more human internet. If you are an individual with a disability or special need that requires accommodation, please contact us directly.