Senior SWE (Search) - Platform

About Nebius: Nebius is leading a new era in cloud infrastructure for the global AI economy. We are building a full-stack AI cloud platform that supports developers and enterprises from data and model training through to production deployment, without the cost and complexity of building large in-house AI/ML infrastructure. Built by engineers, for engineers. From large-scale GPU orchestration to inference optimization, we own the hard problems across compute, storage, networking and applied AI. Listed on Nasdaq (NBIS) and headquartered in Amsterdam, we have a global footprint with R&D hubs across Europe, the UK, North America and Israel. Our team of 1,500+ includes hundreds of engineers with deep expertise across hardware, software and AI R&D. About Tavily We're building the infrastructure layer for agentic web interaction at scale. Our API is designed from the ground up to power Retrieval-Augmented Generation (RAG) and real-time reasoning in AI systems. By connecting LLMs to high-quality, trustworthy web content, we help developers build agents that are not only intelligent — but also informed. We work with some of the most innovative teams in AI — from small startups shaping the ecosystem to the largest enterprises deploying AI at scale. Whether it's powering sales assistants, research copilots, or internal knowledge tools, we're the missing link between LLMs and the real world. The Role We are looking for a Senior Software Engineer to design and build the billing platform behind a novel search engine tailored for agentic AI consumption. This role is based in our New York office, hybrid with the NYC team. Our APIs are used by millions of developers and the AI agents acting on their behalf, all paying based on what they consume. You will own the systems that turn product usage into accurate, trustworthy revenue, supporting flexible billing models—usage-based pricing, subscriptions, prepaid balances with auto top-up, and enterprise contracts. Correctness is non-negotiable: every event must be measured precisely and every invoice must be right to the cent. ‌ In this position, your responsibility will be to: • Design and operate the billing platform end to end, from usage events to invoices • Build metering and usage-aggregation pipelines that turn high-volume events into billable amounts • Design and operate prepaid credit/wallet systems with auto top-up and balance management • Support enterprise/contract billing with custom pricing, negotiated terms, and scheduled invoicing • Build reconciliation, idempotency, and invoice-accuracy safeguards to ensure revenue data is always correct • Lead the migration to the next generation of our billing system with no revenue loss or downtime • Define observability and quality metrics for billing correctness, freshness, and throughput • Ensure billing systems meet audit and compliance requirements ( SOX , financial audit) ‌ What we're looking for : • 6+ years building production backend systems, of which 3+ years actively building and operating billing or metering systems in production • Hands-on experience with usage-based / metered billing: rating, aggregation, and proration logic • Hands-on experience with subscription / recurring billing alongside usage-based models • Hands-on experience with prepaid credits / wallet systems and auto top-up mechanics • Hands-on experience with enterprise / contract billing: custom pricing and negotiated terms • End-to-end integration of a third-party billing platform (Stripe Billing, Metronome, Orb, or Zuora) • Strong expertise in Python and TypeScript/Node (Go a plus) • Production experience with transactional databases (Postgres or equivalent) for financial-grade data • Built high-volume event / usage pipelines into a data wa