Founding Backend Engineer — Billing, Pricing & API Systems

Kindredventures; San Francisco (CA); On-site; USD 150,000 - 230,000; Full time

Benefits offered by this job

Relocation assistance

Visa sponsorship

Health insurance

Dental insurance

Vision care

Team events

Job summary

fal is building the core platform that powers a new generation of AI products. As a founding member, you will own backend systems handling usage, billing, pricing, accounts, access, API keys, and model discovery, designing APIs and data models used by multiple teams and customers.

You’ll start with billing, fraud, and pricing, then expand to accounts, access/identity, API keys, and model discovery, ensuring correctness, reliability, and revenue integrity across the platform.

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 or business domains.
• Can ship product and internal surfaces in React / Next.js / TypeScript.
• Strong systems judgment (source of truth, idempotency, auditability, permissions, observability) and product judgment (workflows, edge cases, customer trust).
• Thrives in ambiguous, cross-functional work where product, business logic, and infra overlap; ships a pragmatic v1 that can evolve.

Responsibilities

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

Skills

API design

Data-model design

Systems judgment

Product judgment

Ambiguous跨-functional work

Tools

Python

TypeScript

React

Next.js

PostgreSQL

Job description

fal is building the core platform that powers a new generation of AI products. As a founding member, you will own backend systems handling usage, billing, pricing, accounts, access, API keys, and model discovery, designing APIs and data models used by multiple teams and customers.

You’ll start with billing, fraud, and pricing, then expand to accounts, access/identity, API keys, and model discovery, ensuring correctness, reliability, and revenue integrity across the platform.