Staff Software Developer

Role Summary:

We’re looking for a Staff Software Developer to help design, build, and operate the systems that power Censys’ Internet-wide scanning, DNS resolution, attribution, and data pipelines.

This role sits at the intersection of backend engineering, distributed systems, and applied Internet research. You will work on production systems that discover, collect, validate, and enrich Internet-scale data across IPs, domains, certificates, services, and cloud infrastructure. You will help improve the accuracy, coverage, freshness, and reliability of the Internet Map that powers Censys’ products and research.

At Censys, we work iteratively, but we are always thinking about the big picture. We’re expanding our scanning and data platform to make the Internet more explainable: richer context, better attribution, clearer relationships, and higher-confidence signals. We’re looking for someone with deep technical ownership, strong production engineering instincts, curiosity about how the Internet works, and the ability to mentor others while building reliable systems.

What You’ll Do:

• Design, build, and operate Internet-scale scanning, DNS, crawling, attribution, and data collection systems.
• Own production backend services and pipelines that collect, process, validate, and enrich massive Internet datasets.
• Improve the quality, freshness, reliability, and coverage of Censys’ Internet Map.
• Build systems that support IP scanning, DNS lookups, protocol fingerprinting, asset attribution, and large-scale data ingestion.
• Lead technical design for distributed services, streaming pipelines, storage systems, caching layers, scheduling systems, and scan orchestration infrastructure.
• Partner with Research, Product, Security, and Engineering teams to turn research ideas into safe, scalable, production-ready systems.
• Make thoughtful tradeoffs around reliability, cost, scale, latency, data quality, and operational complexity.
• Participate in operational ownership of the systems you build, including observability, incident response, and on-call rotation.
• Mentor engineers, review designs, and help raise the technical bar for backend and scanning infrastructure.

Skills You Have:

• 10+ years of software engineering experience building production systems.
• Strong backend engineering experience in systems such as data ingestion pipelines, scanning systems, crawlers, schedulers, APIs, storage systems, or high-throughput services.
• Experience designing and operating systems that handle large-scale data, high request volume, or Internet-scale workloads.
• Strong programming experience; we primarily use Go.
• Experience with cloud infrastructure such as AWS, GCP, or Azure.
• Experience with message queues or streaming systems such as Google Pub/Sub, Kafka, Kinesis, or similar technologies.
• Experience with distributed databases or large-scale storage systems such as Bigtable, Spanner, HBase, Cassandra, Postgres, or similar.
• Strong understanding of reliability, observability, testing, deployment, and operational ownership.
• Ability to write understandable, testable, maintainable code.
• Strong technical communication skills, with the ability to explain complex systems to engineers, product managers, researchers, and leadership.
• Good judgment around when and how to use AI-assisted development tools.

Things that make you stand out:

• Experience building or operating scanners, crawlers, DNS infrastructure, passive/active measurement systems, or Internet data collection platforms.
• Deep understanding of DNS and how it is used in practice, including resolution, delegation, record types, nameservers, and operational edge cases.
• Knowledge of Internet protocols, service discovery, network measurement, protocol fingerprinting, or large-scale crawling.
• Experience with attribution systems, asset mapping, cloud asset discovery, or connecting Internet-facing services back to organizations.
• Experience turning research prototypes into reliable, maintainable production systems.
• Familiarity with gRPC, REST, Protobuf, MessagePack, or other API and serialization technologies.
• Experience building, deploying, and maintaining containerized services in Kubernetes.
• Experience with scan orchestration, scheduling, rate limiting, backpressure, retries, deduplication, or distributed task execution.
• Experience working across the boundary of research and engineering, especially in security, infrastructure, networking, or Internet measurement.
• Curiosity about how the Internet works and a desire to build systems that make it more understandable.