Software Engineer, Billing

Software Engineer, BillingBraintrust is the agent observability platform. By actively applying intelligence to agent traces and automatically surfacing the most critical patterns, Braintrust gives teams the visibility to understand how agents behave in production and the tools to improve them. Teams at Notion, Stripe, Box, OpenAI, and Cloudflare use Braintrust to trace their agents, find the issues in their observability data, and run evals that tell them how to improve.About the RoleWe're looking for a Software Engineer, Billing to build the systems that make Braintrust's pricing, usage, and payments accurate, scalable, and transparent. Braintrust helps teams observe, evaluate, and improve production AI agents. Our customers generate large volumes of traces, run automated and human evaluations, use AI-powered product features, and retain data under different plans and policies. Billing needs to turn those product activities into clear, reliable customer experiences—from usage measurement and plan enforcement to invoices, credits, and account state.You'll work across the billing stack: usage metering, subscriptions and entitlements, payment integrations, invoicing, credits, and the internal systems that reconcile them. This is a deeply technical IC role. It is not a finance-operations role, and it is not a backend generalist role that contributes to billing occasionally.You'll be a technical authority on billing correctness and scale, helping Braintrust launch pricing models that let customers adopt the platform with confidence as their AI workloads grow.What You'll DoCore responsibilities:Own Braintrust billing architecture end-to-end, including metering, plans, subscriptions, entitlements, invoices, credits and payments.Design our billing architecture to solve immediate needs and simplify billing for new features as they are developed and released.Ensure Braintrust accurately measures and bills for product usage, including processed data, evaluation scores, model usage, and data retention.Partner with product, infrastructure, finance, and customer-facing teams to introduce new pricing models and billing workflows with confidence.Build the systems that power Braintrust billing, such as:A reliable usage-metering and aggregation pipeline that turns product activity into accurate customer usage.A subscription, limits, and entitlement system that supports plan allowances, feature access, trials, upgrades, and on-demand usage.Internal tools and APIs for investigating billing anomalies, issuing credits, and helping customers understand their account state.Observability across the billing pipeline, including metering lag, event completeness, reconciliation discrepancies, and payment health.Ideal Candidate CredentialsExpert-level understanding of TypeScript, Rust, SQL, backend systems, APIs, and distributed data-processing patternsExperience building and operating production usage-based billing, payments, or subscription systemsExperience with metering, aggregation, idempotency, reconciliation, and event-driven architecturesExperience integrating with Stripe or similar payment infrastructureExperience building or maintaining financial ledgers, credits, balances, or invoice systems is a plusComfortable shipping end-to-end, from backend infrastructure and data systems to internal tools and customer-facing UIPrevious experience founding or working at startups is a plusHas an appreciation for the tension between moving quickly and preserving customer trust and billing correctnessBenefits IncludeMedical, dental, and vision insuranceDaily lunch, snacks, and beveragesFlexible time offCompetitive salary and equityWifi & cellphone stipendEqual OpportunityBraintrust is an equal opportunity employer. All applicants will be considered for employment without attention to race, color, religion, sex, sexual orientation, gender identity, national origin, veteran or disability status.