Staff Backend Engineer

About Circuit

Circuit is the AI execution layer for the physical economy.

Industrial and manufacturing enterprises run on expertise: the hard-won knowledge of how complex products are engineered, configured, sold, and supported. That expertise is scarce, slow to transfer, and walking out the door as a generation of experts retires. It lives in PDFs, spreadsheets, and the heads of a few people, and the hardest technical decisions wait on whoever happens to know.

Circuit puts expert judgment in everyone's hands. We capture how the best people make critical technical decisions and turn it into agents that do the judgment-heavy work, so anyone, regardless of skill level, can make the right call, from quote to install and support, with the accuracy these environments demand.

Circuit is built by operators. Our leadership team has built and scaled real industrial companies, and we are already live in production with category-leading manufacturers. We are not bolting AI onto an old playbook. We are building the layer that runs the last mile of how the physical economy executes.

As a Staff Backend Engineer, you'll play a critical role in shaping and scaling Circuit's backend systems and infrastructure. You'll own complex backend services built primarily in Go and Python, with a focus on resilience, scalability, and performance under increasing load.

A defining challenge of this team is data scale. As Circuit goes deeper with enterprise customers, the data in our indexes grows dramatically — driving new architectural demands around database sharding, self-hosted storage, efficient embedding indexes, and safe, high-stakes data migrations. Solving these problems is what unlocks continued product velocity for the entire backend team.

Beyond the data platform, a significant portion of Circuit's agentic functionality lives in the backend, and you'll be instrumental in ensuring it can evolve and handle new levels of demand.

Our teams operate with a high degree of independence and ownership. Engineers are expected to communicate early and clearly to avoid surprises, act with urgency, and fix issues without waiting to be asked. We hold a high bar for quality while shipping frequently, testing assumptions early, and learning quickly from real-world feedback. You'll often work through ambiguity by framing problems, asking the right questions, and making progress with incomplete information.

Curiosity and internal drive matter: we expect engineers to deeply understand the systems they build, the customers they serve, and how their work creates real-world impact.

• Lead design, implementation, and scaling of backend infrastructure and services, primarily in Go.

• Own the data platform layer — design and execute database sharding and partitioning strategies, evaluate and potentially migrate toward self-hosted Postgres, and build custom index strategies for embedding-heavy workloads.

• Design and drive data migration strategies that are safe to run against production systems at scale, with minimal downtime and high confidence.

• Ensure backend systems are resilient, observable, and performant under high customer load.

• Drive architectural decisions for long-term scalability and maintainability.

• Contribute significant code to core backend systems, focusing on efficiency, robustness, and developer velocity.

• Establish and promote engineering best practices across the backend team.

• Collaborate closely with product, ML, and frontend teams to deliver high-quality features.

• Mentor and support other engineers, fostering growth and knowledge sharing.

• Proven track record turning ambiguous problem statements into shipped, reliable backend systems, owning work end-to-end from design through production.

• Significant expertise in Go, with deep knowledge of performance optimization, concurrency, and distributed systems.

• Deep, hands, on experience managing Postgres in production at scale — including tuning, replication, vacuuming, and operational ownership beyond managed cloud services.

• Experience running and operating self-hosted Postgres (not just RDS or equivalent), including storage optimization and infrastructure-level configuration.

• Proven…