Software Engineer, Billing

SpaceX was founded under the belief that a future where humanity is out exploring the stars is fundamentally more exciting than one where we are not. Today, SpaceX is actively developing the technologies to make this possible, with the ultimate goal of making life multiplanetary and expanding consciousness to the stars.

SpaceXSI is building Super Intelligence to help humanity understand the universe. Our teams are building the full Super Intelligence stack: from our Colossus supercomputers, to Grok models, to our suite of applications, including Grok Bot, Grok Build, Grok Imagine, Grok Voice, and X. We're creating a powerful flywheel where more compute trains better models, better models power more useful products, and what we learn from people using those products shapes what we build next.

About the role

We're hiring a Software Engineer, Billing to evolve the systems that power how Cursor charges and reconciles revenue across millions of developers and enterprise teams.

You will work across the billing stack — usage metering pipelines, subscription and entitlement systems, payment integrations, and the ledger layer — to make billing accurate, scalable, and transparent. This is a deeply technical IC role. It is not a finance ops role, and it is not a backend generalist role wearing a billing hat.

What you’ll do

• Implement usage and billing systems changes end-to-end, from updates in the UI and raw usage events at the edge to invoiced amounts in Stripe, including the metering pipeline, aggregation logic, entitlement enforcement, and ledger.
• Evolve our ledger system that serves as the source of truth for customer balances, credits, overages, and adjustments — with the correctness guarantees that financial systems require.
• Integrate deeply with Stripe including subscriptions, usage records, invoices, webhooks, and edge cases like mid-cycle plan changes, prorations, and failed payment recovery.
• Build billing APIs and internal tooling that product, finance, and customer success teams depend on to query customer state, issue credits, and investigate billing anomalies.
• Improve observability across the billing pipeline — metering lag, reconciliation discrepancies, invoice accuracy — so the team can quickly detect and debug billing regressions.
• Partner with product, infrastructure, and finance teams to ship new pricing models with confidence and minimal operational risk.
• You will own usage & limits across the product family, payments (stripe + daily jobs), grants & promotions, ledger, and internal data insights. You will be a technical authority on billing correctness and scale.
• You will not own tax compliance, or general finance infrastructure unless it intersects directly with the billing system.
• You will not be a backend generalist who contributes to billing occasionally. This is the core of your scope.
• Revenue accuracy is part of the job, but the goal is to build systems with enough correctness and observability that billing is boring — not to manually reconcile every edge case.

You may be a fit if

• You’ve shipped a usage-based billing system in production and have opinions on metering architecture, idempotency, and exactly-once semantics.
• You’ve integrated deeply with Stripe, understand its data model, and have dealt with erroring webhooks.
• You’ve built or maintained a financial ledger and understand why it’s required.
• You care about correctness and making sure customer’s don’t have to manually review their invoices.
• You can hold the tension between "move fast" and "do not lose revenue or trust."
• You feel comfortable shipping features end-to-end - scaling up infrastructure to tweaking a UI component.

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