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. THE ROLE 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. KEY RESPONSIBILITIES 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. EXPERIENCE 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 experience designing and executing data migrations and database scaling strategies (sharding, partitioning, tiered storage) in live production environments. Experience running services at scale, anticipating scalability, reliability, and downstream system impact. Strong background in service-oriented architecture, microservices, and API design, with a systems-level view of lifecycle costs and long-term maintainability. Proficiency with containerization and orchestration (Docker, Kubernetes). Hands-on experience designing observable and operable systems, using metrics, logs, traces, testing, and alerts to detect and diagnose issues early (Datadog, Prometheus, OpenTelemetry, etc.). Hands-on experience stepping outside core backend ownership into one or more of infrastructure (cloud, IaC), ML systems (Python), or frontend (React) to solve integration problems, unblock teams, and directly implement features end-to-end when that is the fastest path to impact. HUMAN SKILLS Team first, low ego. Optimizes for team and company outcomes over individual wins; challenges ideas with data and reasoning, shares context early, and commits fully once decisions are made. Strong sense of ownership; takes responsibility for outcomes, not just tasks, acts with urgency without waiting to be asked, and leaves systems better than they found them. Bias to action and learning; ships frequently, tests high-impact assumptions early, and uses small, safe-to-fail experiments to learn from real feedback. Customer-impact focused; cares deeply about how reliability, latency, and correctness shape real-world user outcomes and trust. Intrinsically motivated; maintains momentum without external pressure and pushes work through ambiguity to real outcomes. Curious and continuously learning; seeks deep understanding of the product, systems, and users, and challenges assumptions in pursuit of better results. WHAT WE OFFER * High-caliber team of seasoned manufacturing and AI leaders * Help create a category-defining platform transforming how manufacturers sell, support, and innovate * Competitive compensation, meaningful equity, and employer-paid benefits * Flexible PTO and access to the latest AI tools * A values-driven culture that rewards ownership, curiosity and velocity WHO SHOULD APPLY If you’re a senior backend engineer with deep Go expertise, excited about scaling infrastructure under real-world load, and motivated to shape the future of agentic systems at a fast-moving startup, we’d love to hear from you! EQUAL-OPPORTUNITY EMPLOYER We are an equal-opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.