Senior Growth Design Engineer (m/f/d)

Why this role, why now

Blockbrain is growing fast, and growth is where craft meets conversion. Every signup flow, onboarding moment, and landing page is a chance to turn interest into activation and activation into revenue. Right now that potential is largely untapped, and we need someone who treats design as a lever for growth, not just as polish.

This is a rare opportunity to own the entire experience that moves people from first touch to active user. You work directly in the codebase, run experiments end to end, and build the design foundation the team grows on. Design here is a team sport: you are the craft anchor, but the decisions get made together. Real ownership and room to shape things from day one.

What we expect

• 6+ years of experience in product design, design engineering, or frontend-heavy design roles, with a strong portfolio that proves your craft, ideally gained in fast-paced startups or scale-ups where priorities shift and shipping fast matters
• Experience as a growth designer or on growth-focused teams is a strong plus, ideally with ownership of funnels, activation, or conversion, and a mindset that thinks in experiments rather than abstract debates
• Craft obsessive: you care about the difference between a good interaction and a great one, because you have seen how much it matters to whether something converts
• System-thinker first: you design systems, not screens, so your work is coherent across components, states, edge cases, and error conditions
• Technically fluent: you read and write code, understand what is expensive to implement versus cheap, and never ship designs that are beautiful in Figma and painful in production
• Data-driven and user-grounded: you ground decisions in real behaviour and metrics, run lightweight research and A/B tests, and stay decisive under ambiguity by making a call, shipping it, and revising when you learn something
• Fluent English, German is a plus

Expected AI Skills

AI is not a buzzword here, it is part of our daily work and a real multiplier.

• Use AI tools to generate design variations, explore interaction concepts, and accelerate visual production, and leverage coding agents to implement and iterate on frontend code without waiting on others
• Work directly with Blockbrain's own agent platform, stay current on how AI reshapes interface paradigms, and feed real design intuitions back into the product

We are not looking for AI experts, but for designers who treat AI as a creative and engineering multiplier, not a novelty.

• Own the growth-critical surfaces end to end: landing pages, signup, onboarding, and activation flows, from first sketch through shipped component
• Design and run experiments and A/B tests, grounding every decision in real behaviour and conversion data
• Implement your own components directly in the TypeScript/React codebase and close the gap between design intent and production reality
• Define and maintain Blockbrain's component library, interaction patterns, spacing, typography, and motion, keeping it consistent across web, agent UI, and mobile
• Design interfaces for complex agent workflows, configuration surfaces, and human-in-the-loop moments
• Run lightweight user research to validate design decisions and spot new growth opportunities
• Establish design critique practices across the engineering organisation, define what good looks like, and hold the bar

• Flexible Work Models: Full-time position on-site in Stuttgart or Hamburg (3 days per week) with flexible working hours.
• Benefits: Deutschland-Ticket, Wellpass fitness membership, access to the latest AI tools, and regular company and team off-sites.
• Top Team: International team with exceptional talents.
• High Growth Potential: Steep learning curve in a fast-growing AI startup. A high level of personal responsibility and the freedom to actively shape processes.
• Top Equipment: MacBook, iPhone, headset, and all the tools you need to perform at your best.