Senior Full Stack Engineer (d/f/m)
Confirmed on the employer's own hiring board on Oct 15, 2026. First seen by Alion on Sep 11, 2026.
This is a hybrid role, and our office is based in Berlin Charlottenburg.
Responsibilities
This role- Full-stack feature development: Design and implement end-to-end features across our Spring Boot backend services and Astro/React frontend applications, ensuring scalability, performance, and maintainability
- Growth experimentation: Build and iterate on conversion-focused features, A/B testing infrastructure, and data-driven optimizations that directly impact our subscriber growth metrics
- System design and architecture: Shape technical solutions for complex growth features, making informed decisions about API design, data modeling, and integration patterns while considering security, cost, and long-term maintainability
- Cross-functional collaboration: Partner closely with Product, Business Development, and Data teams to translate growth hypotheses into technical solutions, communicating trade-offs clearly and driving alignment
- Technical excellence and mentoring: Establish testing standards, monitoring practices, and quality benchmarks for growth initiatives. Share knowledge and mentor team members in full-stack development practices
Requirements
Your profile- 5+ years of professional software development experience
- Proven track record of AI-supported delivery in backend and frontend
- Experience working in cross-functional product teams, ideally in growth, e-commerce, or B2B platforms
- Solid backend experience with Java/Kotlin and Spring Boot ecosystem, building RESTful APIs and working with relational databases (PostgreSQL & DynamoDB)
- Strong experience with modern JavaScript/TypeScript, React, and contemporary frontend tooling. Familiarity with Astro, TailwindCSS, or similar frameworks is a plus
- System thinking: Understanding of microservices architecture, API design principles, and distributed system patterns
- DevOps awareness: Experience with CI/CD pipelines, observability tools (monitoring, logging, metrics), and cloud infrastructure basics
Ways of Working:
Product mindset: You connect technical decisions to business outcomes, understand how to balance speed with quality, and can identify systemic risks in growth-focused development
Communication: You explain technical trade-offs clearly to non-technical stakeholders and foster alignment across teams and functions
Ownership: You take responsibility for your systems' long-term health, considering dependencies, costs, and maintainability in your decision-making
Growth mindset: You seek feedback proactively, stay current with emerging technologies (especially AI-assisted development tools), and contribute to team learning
Benefits
At Kleinanzeigen, we care about our people - their wellbeing, growth, and life beyond work. Our benefits are designed to support you holistically, giving you flexibility and opportunities to thrive.
Flexibility
Flexible working time (hybrid)
20 days “work from anywhere”
Paid additional parental leave for both parents
Extra paid days off for special occasions (e.g. your wedding or a move)
Wellbeing & Support
Confidential support & coaching for you and your loved ones
Annual company sports events
Pension and life insurance
Growth & Development
Personal development budget
Learning opportunities to grow your skills and career
Perks &Everyday benefits
Corporate benefits and exclusive discounts
An attractive referral program
Transportation allowance
Free shipping on Kleinanzeigen Direktkauf
Kleinanzeigen is an equal opportunity employer that values diversity and inclusion. We welcome people of all backgrounds, races, religions, colours, national origins, gender identities, sexual orientation, ages, marital status, or disability.
If this role sparks your interest but you’re not sure you meet every single requirement, we’d still love to hear from you anyway.