Full-Stack Developer (Node.js / PostgreSQL) -- B2B SaaS Revenue Platform [No Agencies]

INDIVIDUAL FREELANCERS ONLY. Agency proposals will be declined without review. We are a B2B SaaS revenue management platform built on Node.js, PostgreSQL, and React, integrated deeply with QuickBooks Online. Small team, real customers, real revenue. Looking for one senior full-stack developer to ship features, not sit in meetings. Immediate priorities: - HubSpot integration (contract creation from HubSpot into our platform) - AI-powered reporting agent (LLM-based dashboard queries) - QBO integration maintenance (API changes, webhooks, sync optimization) - Bug fixes across billing, revenue reports, and credit memos Must have: - Strong Node.js / TypeScript - PostgreSQL - React - Experience with REST API integrations (QuickBooks, HubSpot, Stripe, or similar) - Ability to work independently with minimal supervision - Available 30-40 hrs/week Nice to have: - QuickBooks Online API experience - LLM / AI integration experience - B2B SaaS billing or revenue recognition domain knowledge - GCP / cloud infrastructure Screening questions: 1. Tell us one thing you have built that you are proud of, and how you use AI tools in your work. Applications that skip this question will not be reviewed. 2. Include a link to your GitHub profile and/or website. Timezone: Overlap with US Pacific required (2-3 hours minimum)