Senior Backend Engineer

We are seeking a Senior Backend Engineer to join the Sightline detection engineering team. You will design, build, and operate high-scale, low-latency backend services that score and protect web and API traffic against automated abuse, working at the core of HUMAN’s real-time detection platform. What you’ll do: - High-Scale Engineering: Design, build, and maintain distributed, high-throughput backend services processing hundreds of thousands of requests per second with strict tens-of-milliseconds latency targets. - End-to-End Ownership: Own services from architecture and implementation to deployment and reliability. This includes full-stack instrumentation (monitoring, alerting, and tracing) to detect and mitigate production issues. - Product Innovation: Implement and evolve real-time detection and decisioning flows within the Sightline Cyberfraud Defense platform, collaborating with security researchers, data science, and product teams. - Cloud-Native Operations: Build and operate services in a Kubernetes environment using a modern GitOps stack (Go, Kafka, Redis, MongoDB, BigQuery, ArgoCD, Pulumi, Crossplane), ensuring robust rollout strategies and safe migrations. - AI-Forward Engineering: Demonstrate a deep passion for the AI-first development frontier and an expert-level ability to leverage assistants and agents to radically accelerate the entire lifecycle - from architectural scaffolding to automated tasks, skills, and complex debugging/testing. - Cross-Functional Collaboration: Partner with adjacent teams to design end-to-end flows that balance security, performance, and customer experience. - Technical Leadership: Contribute to technical design reviews and code reviews, raising the bar for quality and operational excellence across the team. Who you are: - Experience: 5+ years of experience building backend services with a strong grasp of modern distributed systems design. - Language Proficiency: High proficiency in at least one backend language such as Go, Java, or Scala, including a strong command of concurrency and multithreading concepts. - Cloud Infrastructure: Proven experience building and operating production systems in a major cloud provider (GCP or similar), including containerized workloads and CI/CD pipelines. - Data Systems: Hands-on experience with datastores and messaging systems (e.g., MongoDB, Redis, Kafka, or Postgres). - Networking & APIs: Solid understanding of networking fundamentals, HTTP-based services, and best practices for secure, reliable APIs. - Troubleshooting: Practical experience with monitoring tools (e.g., Prometheus, Grafana, Opsgenie) and resolving complex, distributed production issues. - Delivery: Comfortable working both independently on complex technical problems and as part of a collaborative team, driving projects end-to-end. Nice to Have - Previous experience in security, fraud detection, or risk scoring systems, especially in high-volume web or API environments. - Deep, hands-on experience with Go in production, including performance tuning, profiling, and optimizing latency-sensitive services for cost and availability at scale. 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,