Senior Full-Stack Engineer to Build GTM Analytics Platform

We're looking for a senior full-stack engineer to architect and build a GTM analytics platform from the ground up. The goal is to create one centralized system that connects the entire revenue funnel: Lead source → channel → account → opportunity → sales stage → closed revenue — and gives us complete visibility into where pipeline comes from, how it moves, what converts, what doesn't, and why. The platform will integrate with CRMs and GTM tools such as HubSpot, Clay, Apollo, Go HighLevel, Heyreach, Instantly, Slack and similar platforms through APIs and webhooks. It will track attribution, conversion rates, stage progression, pipeline velocity, sales cycles, win rates, and closed revenue, with a clean centralized dashboard. We're looking for a builder, not simply a developer who executes tickets. You should be able to take the business requirements, recommend the technical architecture, build the database and backend, develop the frontend, handle integrations, and take the application from concept through production. You should have strong experience with Python, JavaScript/TypeScript, React/Next.js, PostgreSQL/SQL, APIs, webhooks, databases, and modern cloud infrastructure. Experience building SaaS products, analytics platforms, CRM integrations, or data-heavy internal tools is highly relevant. You should also be highly proficient with AI development tools such as Codex, Claude Code, Cursor, or similar tools and use them extensively in your development process. We're less interested in credentials and more interested in one question: Can you take this idea and build it? When applying, please send 2–3 examples of applications or systems you've personally built end-to-end, explain what you personally built, and tell us which AI development tools you currently use.