Senior Infrastructure Engineer

<h2>Infrastructure Engineer</h2> <p>We move terabytes of campaign and engagement data, and you'd own the foundation it all runs on.</p> <p><strong>About JustAI</strong></p> <p>We're a YC-backed team building the AI platform that runs marketing for the world's best companies. Marketers describe a campaign in plain language, and our platform turns it into running code that generates, tests, and executes personalized messaging across email and push at scale.</p> <p><strong>The founders</strong></p> <p>We were at X during the Elon takeover. I had to rewrite the backend infrastructure that now powers the core user and tweet services. You'll get to work closely with us.</p> <p><strong>The role</strong></p> <p>You'll own the foundation everything runs on: the large-scale data pipelines that feed our analytics and models, the compute and storage substrate, and the reliability, observability, and cost of the whole system. This is an early, high-ownership role. You'll be building a lot from 0→1 and owning it end to end as we scale.</p> <p><strong>What you'll do</strong></p> <ul> <li>Own and scale our data infrastructure, including large-scale batch and streaming pipelines, warehouse design, and the storage layer behind them.</li> <li>Run and harden our compute platform: orchestration, autoscaling, resource isolation, and deployment of containerized workloads.</li> <li>Own the observability and reliability backbone (metrics, tracing, alerting, SLOs) and drive down both incidents and cost.</li> <li>Tackle the lowest-level scaling problems: data partitioning, throughput, query and scan cost, and distributed-systems failures at volume.</li> <li>Accelerate how quickly other engineers can ship code safely.</li> </ul> <p><strong>What we're looking for</strong></p> <ul> <li>5+ years in infrastructure, SRE, or data platform roles, with hands-on experience building and operating large-scale systems at a low level.</li> <li>A 0→1 builder. You've stood up infrastructure from scratch and owned it as it grew, not just maintained someone else's.</li> <li>Battle scars from lower-level, large-scale systems. You've run things like Kubernetes, Spark/Hadoop-class data processing, distributed storage, or high-throughput streaming in production.</li> <li>A track record of debugging hard problems at scale across failures, cost, and performance.</li> <li>Strong instincts for reliability, cost, and operability. You treat infra as a product with users.</li> <li>We care more about whether you've operated systems at scale than which specific tools you've used.</li> <li>Experience with machine learning systems a plus.</li> </ul>