Senior Growth Design Engineer (m/f/d)

BlockBrain; Hamburg; On-site; EUR 85,000 - 120,000; Full time

Benefits offered by this job

On-site in Stuttgart or Hamburg

Deutschland-Ticket

Wellpass fitness membership

Access to AI tools

Regular off-sites

MacBook, iPhone, headset

Job summary

Blockbrain is seeking a senior designer to own growth-critical surfaces from landing pages to activation. You will run experiments, ship components in TS/React, and shape a cohesive design system across web, agent UI, and mobile. This role emphasizes data-driven decisions and a strong craft ethos within a fast-growing AI startup.

You will collaborate closely with engineers and product teams, serving as the craft anchor and driving conversion-focused design across the customer journey.

Qualifications

• 6+ years in product design, design engineering, or frontend-heavy roles.
• Growth design experience on funnels, activation, or conversion.
• Obsess over craft and user interactions that drive conversion.
• System-first designer who builds cohesive design systems.
• Technically fluent; able to implement in code with React/TypeScript.
• Data-driven and able to run experiments and interpret results.
• Fluent in English; German is a plus.

Responsibilities

• Own growth-critical surfaces end to end: landing pages, signup, onboarding, activation.
• Design and run experiments and A/B tests with real metrics.
• Implement components directly in TS/React in the codebase.
• Define and maintain Blockbrain's component library and patterns.
• Design interfaces for complex agent workflows and human-in-the-loop moments.
• Run lightweight user research to validate decisions.
• Establish design critique practices across engineering teams.

Skills

Growth design

Product design

Frontend design

A/B testing

System thinking

Data-driven

English fluent

German helpful

Job description

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.

Your mission

• 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
• Implementyour 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

Why us?

• 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.

About us

For mid-sized and enterprise companies in DACH, knowledge is the last real competitive lever. Yet knowledge gets stuck in tools and SharePoint folders — or disappears when experts leave. While IT is still planning, employees are already using ChatGPT and the like — without governance, and sensitive data is leaking out.

With the Knowledge Bots platform, Blockbrain creates what companies truly need: AI-powered knowledge management that is quick to implement, flexibly scales, and operates in a compliant manner. Teams use our GenAI building blocks to build tailored AI assistants, agents, and workflows in minutes — just like Lego.

Series A funded with strong growth momentum (10x product usage & 5x revenue in 2025)

Enterprise clients such as Roland Berger, Bosch, and Harting from industries including manufacturing, finance, and legal — sectors with the highest security requirements

ISO 27001 certified, EU AI Act ready. Made in Germany.