Senior Fullstack Developer (m/w/d)

The client is looking for an experienced Fullstack Developer to join the founding team in building a cloud cost optimization platform.

You'll build the customer-facing experience that makes cloud cost optimization feel effortless. Starting with our signup flow and a 1-page dashboard, you'll create the web application that onboards customers in seconds, visualizes their AWS savings, and build the complete Slack integration where our DevOps AI agent lives as a team member.

Your immediate focus: Build the customer onboarding flow, design the initial dashboard showing savings plans and group buying benefits, create the complete Slack integration (Slack Bolt SDK, webhooks, interactive components, bot UX), and build responsive interfaces that work across web and mobile. You'll also build admin interfaces for our internal team to manage savings plans and customer reports.

You'll establish the client's frontend architecture patterns, implement their design system, and build the foundation for features like automated savings plan dashboards, and cost anomaly detection interfaces.

What you bring

* Expert modern frontend developer proficient in React, Vue.js, Svelte, or any modern web framework with TypeScript
* Full-stack capabilities with Python/FastAPI skills to build APIs and integrate with our monolithic backend
* Product and UX mindset to design signup flows, onboarding experiences, and intuitive dashboards without dedicated design support
* API integration expertise for connecting with AWS billing data and our internal backend services
* Startup experience having built 0→1 products with rapid iteration and autonomous execution
* You are a curious builder, who loves getting to the bottoms of things, with a hacker mindset to just try things out

* You are a hard worker with a strong sense of urgency, who takes ownership and fosters a fast-moving, high-responsibility environment
* You value direct communication to increase speed and as a way to improve yourself and your colleagues
* You have impressive achievements from previous jobs and from side projects