(Senior) Full Stack Engineer – Apps (m/f/d)

Your Role

We're looking for a Senior Full Stack Engineer - Apps (m/f/d) to build the products that put AI-powered revenue intelligence directly into the hands of sales teams. You'll work across our entire stack, from React interfaces that make AI insights actionable to JVM-based backend services, owning features end to end and shipping product that sales teams rely on every day.

This is a hands-on role for someone who wants to work close to the product, take ownership of production systems, and build scalable software in a fast-moving, AI-first environment.

Your Mission

• Own features end to end: Take features from concept to production across frontend and backend, from user interface to database to deployed service
• Build multi-surface solutions: Ship product improvements across our web app, mobile-optimized field sales solutions, and CRM integrations
• Surface AI insights: Develop React applications that make complex, AI-generated revenue intelligence actionable for sales teams
• Power the platform: Build and maintain backend services in Kotlin with Spring Boot that handle scale and complexity
• Design great APIs: Create and evolve both GraphQL and REST APIs that serve our diverse product surfaces
• Work with data: Design solutions using PostgreSQL for transactional data and ClickHouse for analytics
• Own what you deploy: Take full responsibility for your services in production. You build it, you run it, you improve it
• Shape our architecture: Participate in code reviews and technical discussions that influence our technical direction

Your Profile: What You Need to Succeed

We care more about your ability to solve problems and ship product than a checklist of technologies. That said, here's what success in this role looks like:

• Experience: 5+ years of professional software engineering experience shipping production code
• Frontend expertise: Strong TypeScript and React skills with real-world production experience
• Backend foundation: Solid JVM experience (Java or Kotlin) and practical Spring Boot experience
• API and data design: Proven experience with relational databases and thoughtful API design
• Operational basics: Comfortable with Docker and Kubernetes fundamentals
• High agency: You identify problems and solve them without waiting for direction, with a clear bias toward action
• Product mindset: You think about user impact and business outcomes, not just technical elegance

Nice to Have

• Experience integrating AI or ML capabilities into production products
• Familiarity with analytics databases such as ClickHouse or BigQuery
• Experience with gRPC and microservices patterns

Benefits

• Development Opportunities: Steep development opportunities without entrenched hierarchies.
• Culture: We are an ambitious team that wants to achieve a lot with Acto, but we don't take ourselves too seriously and like to have fun together, be it working together or at regular team events.
• Flexibility: Berlin-based with flexible remote work. You can work from home often, with regular in-person time in our Berlin office, particularly for key meetings and collaboration.
• Health and work-life balance: Enjoy 30 days of vacation and an attractive Wellhub membership.
• Ownership: Whether you are an intern or a full-time acto-naut, Acto instills a deep sense of ownership, where every team member is entrusted with meaningful responsibilities and the autonomy to make impactful decisions.
• Equipment: You will receive a state-of-the-art hardware setup with a choice between Mac and Windows.

About Us

At Acto, we're building agentic AI systems that go beyond chat, systems that reason, act, and deliver results across complex real-world workflows for field sales teams.

Our mission is to turn enterprise data and tools into intelligent, decision-capable agents that support people where it matters: in meetings, in daily operations and on the road. We're a small, product-focused team combining deep experience in AI, ML engineering, and systems design.

We started in 2021 and since then have not only been able to win renown medium-sized companies as customers, but also bring experienced investors such as 468 Capital and Cusp Capital on board.