Senior Backend Engineer, Autonomous Agents

We run autonomous agents that carry out long, multi-step operations with nobody in the loop. You own the platform they run on: its architecture, its reliability, and how far it can be pushed. Today that platform depends on services other teams own, and it runs only for us. Your job is to make it independent, and then to make it something a customer can run themselves. About CUBE AI CUBE AI is an Agentic Crime Prevention Platform, built at the intersection of agentic AI, cybersecurity, and fraud prevention. We serve the institutions on the front line of an exploding wave of AI-powered crime: banks, fintechs, and the platforms criminals cannot operate without. Our mission is ambitious: make the world a safer place. How we do it is the part we're most excited about, and the part we're happy to walk you through in a conversation rather than on the open internet. Why this is the seat to take This is a rare seat on a rocket ship. CUBE AI is early, exceptionally ambitious, and backed by some of the world's leading investors. Our founders have built and scaled startups to unicorn valuations and exits, and have run mega teams at mega companies. We are building the company that puts the institutions the modern economy runs on back on offense against AI-powered crime. The closest analogy is joining Palantir in its early days: a hard mission, a category we're defining rather than entering, and a small group of exceptional people compounding fast. If you want a comfortable role, this isn't it. If you want the defining chapter of your career, your best work alongside people who make you sharper, keep reading. What you'll do Own the architecture, reliability and scale of the autonomous agent platform.Cut the platform's dependencies on services other teams own, so its roadmap becomes its own.Widen the range of operations an agent can complete without human intervention.Take the platform from internal-only to something an external team can run for themselves.Build the observability that makes an autonomous run explainable after the fact.Set the engineering standards for agent infrastructure as it grows.Our stack Python, FastAPILangGraph ecosystem for agent orchestrationPostgreSQL as the backend storageFrontier LLM APIsGKE, Docker and GitHub Actions, with promotion through dev, staging and productionAI-assisted, agentic development workflowsWhat we're looking for The bar (non-negotiable, every role): Extreme drive and passion for the work and the mission.Extreme ability to learn fast and operate with confidence in uncertainty.Extreme IQ and EQ. You raise the level of every room, and you lose an argument gracefully the moment someone's right.For this role specifically: You have built production backend systems and owned their architecture.Experience with long-running, stateful workloads and the failure modes they bring.Strong Python skills, and comfortable reasoning about distributed systems.Comfortable owning a relational schema in production: migrations, data growth, and queries that stay fast as tables grow.A track record of taking an internal system to external-facing quality.Judgment about reliability when the conditions are outside your control.Fluent written and spoken English.Bonus points Agent frameworks or workflow engines: LangGraph, Temporal, Airflow or similar.Multi-tenancy, isolation and permissioning for external users.Kubernetes beyond deploying to it.An adversarial domain: fraud, security or abuse.How we work and who thrives here Our core locations are Lithuania, London, and New York, and we consider remote-first candidates who can travel as needed for their role. We write more than we meet and move at warp speed. We're an AI-first company: every person here is amplified by a layer of AI agents, and we scale capability, not headcount. We don't buy services, we buy results. We're drivers, not passengers, so we hire people who go and do it without waiting for permission. We move fast, and we use judgment where it counts: we hold sensitive data and the trust of the institutions we protect, and we never cut corners there. Our culture runs on five virtues: A pedantic bar for quality. Work that is thorough, complete, and on time. We trust each other to deliver, fully.Radical ownership. See it, own it, fix it. Never defer a problem or an opportunity. You will never be reprimanded for taking initiative.Relentless energy and audacity. Building something exceptional demands enormous energy. We move forward with maximum drive.Automate everything. We scale the capability of our people, not the headcount. We always hunt the 10x multiplier, working alongside AI agents rather than piling on process.Have fun. We work with people we genuinely enjoy. It gets us through the hard stretches and keeps politics out.What's in it for you Uncapped growth. In a company moving this fast, scope finds the people who can carry it. Ownership and title are earned in months, not years.Real self-realization. This is a place to become the most capable version of yourself, next to people operating at the top of their game.A direct line to senior product and engineering leaders, and a real say in where the product goes.You share in the outcome. When the company wins big, you win big.What we offer Join a rocket ship. Let's discuss compensation and the rest of the details on our call. CUBE AI is an equal-opportunity employer. We welcome applicants of every background and will support any accommodations you need during the hiring process.