Software Engineer - Billing

### About the job

FriendliAI is hiring a Billing Engineer to build our next-generation, in-house metering and billing platform. The billing system should power complex, rapidly evolving pricing across subscriptions, usage, tiers, discounts, overages, and custom enterprise contracts. You’ll be the primary contributor implementing event-driven pipelines, pricing/rating logic, and deep Stripe integrations. You’ll work with other software engineers for key decisions while going hands-on in Python/Go services, Kafka-based event pipelines, and cloud operations across AWS (plus other cloud services).

We are looking for someone who loves turning messy real-world usage into precise, auditable invoices; who designs for correctness, configurability, and change as our pricing strategy evolves continuously.

### Key Responsibilities

• Design and implement Kafka-backed metering and event pipelines
• Implement pricing and rating logics. Encode plans, tiers, proration, discounts, custom contracts, and more. Should support mid-cycle price and plan changes safely.
• Own Stripe integrations. Implement Payments and invoicing, webhooks, retries, refunds, and reconciliation workflows.
• Model billing domain by developing data models for product catalogs, entitlements, and charge items.
• Implement various payment strategies.
• Ensure the accuracy of the billing system and provide observability to the system.

### Qualifications

• 3+ years of backend engineering experience building production services.
• Bachelor’s or Master's degree in Computer Science, Computer Engineering, Electrical Engineering, or equivalent
• Proficiency in Python; strong software design and code quality.
• Experience with event streaming (Kafka or similar) and distributed system concepts.
• Hands-on experience integrating Stripe Payments & Invoicing (or equivalent payment platforms).
• Strong SQL and data modeling skills; comfort with large-scale usage data and financial accuracy.
• Experience with ClickHouse (or similar OLAP systems) for high-volume usage aggregation and analytics.
• API design expertise with gRPC and REST: resource modeling, versioning, backward compatibility, authn/z, pagination, idempotency.
• Cloud experience with AWS and familiarity with containers and CI/CD.
• Clear written and verbal communication; ability to translate pricing/business rules into robust systems.

### Preferred Experience

• Background in a fintech company or experience building in-house usage-based billing platforms.
• Knowledge of dunning strategies, dispute/chargeback workflows, and revenue assurance.
• Experience integrating with cloud marketplaces (e.g., AWS marketplace), including private offers, SaaS/usage metering and entitlements, fulfillment APIs, and downstream invoicing.
• Experience with infrastructure-as-code and security best practices.

### Benefits

• Flexible working hours
• Daily lunch and dinner provided; unlimited snacks and beverages
• Supportive and highly collaborative work environment
• Health check-up support and top-tier equipment/hardware support
• A front-row seat to the generative AI infrastructure revolution
• Competitive compensation, startup equity, health insurance, and other benefits.

### About FriendliAI

FriendliAI is building the world’s best AI inference platform that makes large language and multi-modal models fast, efficient, and deployable at scale. We power high-throughput, low-latency AI workloads for organizations worldwide and integrate directly with Hugging Face, giving developers instant access to over 500,000 open-source models.

We are a small, fast-moving team doing work that matters at one of the most exciting moments in the history of technology. With our world-class inference engine, we are building a platform that the AI industry can actually rely on.