**Zertificon Solutions – Software Manufacturer since 2004.**
We are IT security specialists: our products encrypt business communications. More than 25% of the 100 highest-revenue companies in Germany, as well as hundreds of medium-sized enterprises across all industries, already use our Z1 encryption solutions. We have big plans and continue to grow steadily. Nearly 140 employees are already working with us in Neukölln. Join our professional, highly qualified team: take on challenges, share your knowledge, learn new things, and discover your potential!

**You have experience, a broad view, and deep knowledge – and you have great ambition?**
You’ve just found your door.

We are looking for a hands-on **Lead Java Developer** who is ready to take over one of our teams. As the Lead, you will shape the team and take it to the next level. You will be deeply involved in defining how things will run.

### Your tasks

### Development and Product

- Transforming and creating a containerized microservice architecture in Java (or other languages)
- Developing new products while combining legacy and monolithic Z1 software with new containerized versions
- Renovating, rebuilding — and making it shine
- Integrating legacy software components (monoliths) into new product solutions
- Proactively planning and developing Z1 products with your team
- Finding new paths and solutions to strengthen our market position

### Alignment with Other Teams

- Aligning your work with other R&D teams to ensure a smooth fit in the overall architecture
- Being part of a cross-functional team that isn’t afraid to explore new technologies or thought patterns

### Team Building and Leadership

- Helping develop the team to the next level
- Coordinating your team effectively and understanding its capabilities deeply
- Mentoring and guiding team members to deliver the features and results our enterprise customers expect

### Miscellaneous / Strategic Thinking

- Analyzing blockers or issues in the development strategy — and preventing them before they happen

### Your profile

- You have a modernization mindset: turning complex legacy systems into clean, maintainable architecture
- You have successfully worked *and led* in a development team for at least 7 years, delivering solutions and products together
- You have at least 5 years of practical experience working with Java. We primarily use Java 21
- You have deep knowledge and understanding of software architectures such as monoliths and microservices
- You have experience with security topics such as PKI, S/MIME, OpenPGP, X.509 certificates, and PGP keys
- Ideally, you already have knowledge of Email, SMTP, JavaMail, and BouncyCastle
- You demonstrate professional proficiency in both English and German (C1 level or higher).

### You are proficient with the following technologies:

- **Java:** Java 21
- **Linux:** Basic proficiency in Linux commands
- **Shell Scripting:** ANSI Shell, Bash
- **Frameworks:** Spring MVC, Spring Boot, Spring Data, Spring Integration
- **Message Brokers:** NATS / RabbitMQ / Kafka
- **Containerization:** Docker, Kubernetes
- **Microservice Design:** Experience with microservice architectures
- **Monoliths:** Experience working with monolithic applications
- **Build Tools:** Gradle
- **Software Testing Methodologies**

Knowledge of Smart Cards or Hardware Security Modules is not required but is a great advantage.

### We offer:

- **Flexible hours** and **home office** options
- **Mobility:** free Germany-wide public transport ticket, bike leasing, or parking
- **Subsidies for meals:** (e.g., delivery services) and home office internet
- **Urban Sports Club membership** for flexible fitness and wellness
- **Office perks:** rooftop terraces & green courtyard, organic fruit and drinks, personal packages accepted at the office
- **Get-togethers:** monthly Pizza Friday, regular team events, big summer party
- **Responsible leadership:** structured onboarding, regular feedback, clear goals
- **Innovative without startup risk:** profitable for 20+ years, self-funded innovation with strong global potential
- **International team:** 120+ colleagues from 30+ countries, open and collaborative culture

**If that resonates with you, we’d love to hear from you.**

Want to know more? Please have a look at our Work at Zertificon page: [https://www.zertificon.com/en/it-jobs-berlin/work-at-zertificon](https://www.zertificon.com/en/it-jobs-berlin/work-at-zertificon)

**Questions?**

You can reach our HR team at

[jobs@zertificon.com](https://mailto:jobs@zertificon.com)