Backend Infrastructure Engineer

We're hiring a Backend/Infrastructure Engineer to own the systems everything else runs on: our AWS environments, deployments, CI/CD and observability — and then to build something more ambitious: Simu, our agent simulation and evaluation system, which will let us test AI agent behaviour automatically before it ever reaches a user. This is not a ticket-queue DevOps role. It has two mandates. The first is to make our infrastructure boring: reliable environments, fast safe deployments, clear observability, no surprises. The second — once the first is under control — is to be the engineering owner of Simu: a harness that runs scripted, simulated user sessions against our real agents and scores the results, so that a prompt or architecture change can be verified against our known failure modes in an afternoon instead of a week of manual test calls. It is one of the highest-leverage systems we will build this year, and you will build it. About Kulu Kulu is a high-performance, high-bandwidth communication team. We run live daily standups, Slack constantly, and jump into huddles rather than letting long async threads develop. Product, engineering and commercial conversations overlap heavily. This suits people who enjoy working closely with highly engaged colleagues, talking through hard problems in real time, sharing unfinished work, and moving quickly as new information emerges. It's probably not the right environment if your ideal style is to receive a well-defined problem, disappear for the day, and communicate primarily through async updates. There will be focused individual work — but we optimize for the speed and quality of the team as a whole. We are deliberately moving toward a more in-person culture in Bali. Tasks Infrastructure & deployment ownership — Own our AWS environments (dev, staging, production) end to end: services, networking, secrets, cost, and the promotion path between environments. You take this over from a departing engineer with a proper handover, then make it yours. CI/CD & release engineering — Own the pipelines that build, test and deploy every service. Make releases fast, reversible and predictable: staged rollouts, clean rollbacks, feature-flag discipline (we use PostHog), and no configuration that exists only in someone's head. Observability — Own logging, metrics and alerting across the stack (CloudWatch, Langfuse, PostHog). When something goes wrong in a live session, the engineers debugging it should have the trace they need — you make that true. Security & compliance engineering — Work with the CTO on our security and privacy commitments to enterprise customers: data retention controls, PII handling, secrets management, audit trails. Developer experience — Keep local development, test data and tooling in a state where a small team ships fast without stepping on each other. What success looks like Two North Stars. First: infrastructure is boring — deployments are a non-event, environments behave identically, incidents are rare and diagnosable, and nobody thinks about AWS unless something is being improved. Second: Simu exists and matters — within your first months, a first version runs real scenarios against the agent automatically, and over time it becomes the release gate the whole engineering team relies on. If a year from now agent changes still get verified by humans making manual test calls, the second mandate has failed regardless of how tidy the infrastructure is. Requirements Strong backend engineering fundamentals, with production Python experience Real production AWS experience: you have owned deployed systems, not just contributed to them Solid CI/CD experience (e.g., GitHub Actions), containers (Docker), and infrastructure-as-code habits Pragmatism: you build the simplest thing that makes the problem go away, and you automate what repeats High agency and ownership — this role has no one behind it; you are the person who makes sure it works Fluent/Advanced spoken and written English, with the ability to communicate confidently and professionally. Our company language is exclusively English. Nice to have (optional): Experience testing or evaluating LLM applications (evals, harnesses, LLM-as-judge); real-time media infrastructure (e.g., LiveKit, WebRTC); TypeScript; Terraform or similar; observability and analytics tooling (Langfuse, PostHog); PostgreSQL; exposure to security/compliance work (SOC 2 or similar). What we are not looking for This is unlikely to be right if you want Kubernetes-scale platform engineering for its own sake, prefer writing policy and process to writing code, see testing as QA's job rather than an engineering problem, need a large team around you, or want to specialize so narrowly in infrastructure that building an application-level system like Simu feels out of scope. The whole point of this role is that one person owns both. Benefits IDR 35–45m/month gross Our Operating Principles: Always Be Hustlin' – Move fast, outwork the competition, stay scrappy. Relentlessly Curious – Reason from first principles, question assumptions and explore better ways. Super Pumped – Show relentless enthusiasm and drive. Make Magic – Create experiences that delight customers. Obsess Over the Details – Perfect the product experience, no matter how small. Big Bold Bets – Think big, take risks and go after huge, transformative opportunities. Ownership is Key – Own the outcome, not just the task. As Kulu grows, this role naturally expands with the Foundation team — a full-stack engineer will join on Simu, and there is a clear path to owning our infrastructure and reliability function outright.