BE ONE STEP AHEAD: Help us make the Internet a safer place!

The digital world faces a constant storm of evolving cyber threats, and IT professionals are on the front lines, defending their organizations‘ most valuable assets against increasingly sophisticated attacks. At Link11, one of Europe’s leading providers of cybersecurity solutions, we know that pressure well. We protect companies and public authorities through meticulous attention to detail and the early adoption of cutting-edge methods, and we take full responsibility for our customers‘ security.

Our market reputation is built on enterprise-grade cybersecurity that keeps IT networks and critical applications safe, so our customers can focus on their core business. With AI-driven technology and patented DDoS protection, and a portfolio spanning Network DDoS Protection, WAAP, Secure CDN and Secure DNS, we are constantly finding new and better ways to strengthen their defenses.

Above all, we are a team of passionate people united by one mission: to make the internet a safer place. More than 100 colleagues work across our international locations, including Frankfurt, Lisbon, Tel Aviv and Vancouver, many of them fully remote. Are you highly motivated and looking for a challenging, rewarding role where you can truly make a difference? Then you are very welcome at Link11. Shape our digital future with us.

Deine zukünftigen Herausforderungen:

• Operate, scale and safeguard our PostgreSQL, ClickHouse and Elasticsearch clusters, which provide data redundancy across multiple datacenters and form the backbone of our DDoS defense and WAAP platform.
• Design and maintain high-availability and replication topologies, plan failover and disaster-recovery strategies, and ensure data integrity and durability even when an entire datacenter goes offline.
• Own the full schema lifecycle – review and ship versioned migrations and their matching reverts, enforce our SQL coding guidelines, and keep changes safe to roll out across clusters under heavy load.
• Tune performance end to end: query optimization, indexing, partitioning and sharding strategies, and capacity planning for ingest-heavy OLAP workloads (ClickHouse) alongside transactional OLTP workloads (PostgreSQL).
• Integrate and Improve monitoring, alerting and backup automation so issues are caught before they reach our customers, and so recovery is fast, tested and reliable.
• Work closely with our development and operations teams as the go-to expert on data modeling, storage and retrieval, supporting them in complex debugging and troubleshooting tasks.
• Contribute to a performance-critical environment where efficiency, scalability and reliability matter every day.

Deine Skills:

• Solid experience administering relational databases in production, with strong expertise in PostgreSQL (replication, high availability, backup/restore, query tuning).
• Hands-on experience with ClickHouse or comparable column-oriented / OLAP databases, including partitioning, MergeTree engines and large-scale ingest.
• Experience operating Elasticsearch (cluster sizing, sharding, index lifecycle management, query and indexing performance).
• Practical experience running databases in clustered, multi-datacenter setups with replication, failover and data redundancy.
• Strong command of SQL and a deep understanding of indexing, query execution plans, partitioning and performance optimization.
• Comprehensive experience with Linux operating systems and a good understanding of networking, storage and how they affect database performance.
• Solid grasp of backup, disaster recovery and monitoring/observability practices for data systems.
• A mindset geared toward sharing knowledge, learning continuously, and contributing to technical discussions.
• Ability to work both independently and collaboratively, while communicating requirements, challenges, and progress clearly to technical and non-technical stakeholders.
• Excellent communication skills in English or German.

Wir sind Link11:

• We live our startup mentality at heart. The professional framework gives us the growth and stability of Link11- founded in 2005. We are still strong today working alongside the founders and the management team.
• We are full of energy, have short decision-making paths and bring changes directly on the way.
• We live a positive, interactive and appreciative working atmosphere in which all employees can contribute.
• We encourage the further development of our employees.
• We are willing to leave our comfort zone for innovation and improvement because we want to be the best in the market.
• We have received several awards for our forward-looking solutions.

Du bist richtig bei Link11:

• Become part of a highly motivated team in which we treat each other with respect.
• Meet your colleagues at eye level. We are all equal and without barriers.
• Live and develop your strengths in a friendly atmosphere.
• Organise yourself in a flexible working model, because you are more than just your job.
• Lead us to success with your skills.
• Community is the trump card: team events, sundowners, after work parties bring us together (also internationally).
• Taking care of our team doesn’t end at the coffee machine or a filled fruit basket!
• Look forward to interesting benefits such as fitness, JobRad, support for daycare fees and much more. We are cooperation partners of national and international associations and authorities.

Informationen und Kontakt

Do you have any questions about this position? Contact us directly at jobs@link11.com. Your contact person is Nadine Saewert from the People Management department.
We look forward to getting to know you and learning more about you as a person and your professional career.
Got it? Then simply apply via our careers page at https://www.link11.com/de/karriere/, stating your salary expectations and your soonest possible starting date.
We promise we will reply to you within 48 hours of receiving your application with feedback on whether we can get together for a telephone interview!

Link11 GmbH
Lindleystrasse 12
D-60314 Frankfurt am Main