Senior Backend Engineer — Billing, Pricing & APIs

fal - Features & Labels; San Francisco (CA); On-site; USD 180,000 - 230,000; Full time

Benefits offered by this job

Relocation + visa sponsorship to San F

Health, dental, and vision

Equity

Learning and growth

Team events and offsites

Job summary

fal - Features & Labels is building the core backend platform for a generation of AI products, owning billing, pricing, accounts, access, API keys, and model discovery. You join early to shape APIs and data models with a focus on correctness and revenue.

As a founding member, you will start with billing and pricing and expand across the portfolio, working with product, infra, finance, revenue, security, and customer-facing teams to turn complex workflows into durable systems.

Qualifications

• 5+ years building reliable production backend systems (Python and/or TypeScript).
• Strong PostgreSQL — schema design, queries, migrations, performance.
• API & data-model design for complex product domains.
• Can ship product and internal surfaces in React / Next.js / TypeScript.
• Strong systems judgment and product judgment; cross-functional collaboration.

Responsibilities

• Own billing and pricing first — metering, usage roll-ups, pricing logic, and customer/admin surfaces.
• Design APIs, data models, and product contracts other teams safely build on.
• Grow into broader portfolio — accounts, access/identity, API keys, and model discovery.
• Engineer for correctness and resilience: source of truth, idempotency, auditability, permissions, observability.
• Own operational health, including on-call for the systems you build.
• Partner across product, infra, finance, revenue, security, and customer-facing teams.

Skills

Backend systems

Python

TypeScript

PostgreSQL

API & data-model design

React/Next.js

Cross-functional collaboration

Tools

React

Next.js

Job description

fal - Features & Labels is building the core backend platform for a generation of AI products, owning billing, pricing, accounts, access, API keys, and model discovery. You join early to shape APIs and data models with a focus on correctness and revenue.

As a founding member, you will start with billing and pricing and expand across the portfolio, working with product, infra, finance, revenue, security, and customer-facing teams to turn complex workflows into durable systems.