Temporary Cloud engineer for streaming platform (Kafka) - C

About Proximus Luxembourg

Proximus Luxembourg is a leading historical player in the ICT & Telecoms markets. Proximus Luxembourg addresses both residential and business markets through its commercial brands Tango, Proximus NXT and more recently Codit.

With PSF support status, the company has almost 800 employees. All these experts share a passion for digital technology, a spirit of openness and innovation, and a desire to simplify, connect and make their customers' personal and professional activities ever more secure.

Proximus Luxembourg is actively contributing to the acceleration of Luxembourg's digitalisation and its economic influence through the development of connectivity, resilient infrastructures and 5G, as well as innovative technologies such as Blockchain, Artificial Intelligence, Machine Learning and IoT.

Proximus Luxembourg is a subsidiary of the Proximus group (Euronext Brussels: PROX), provider of digital services and communication solutions operating in the Belgian and international markets.

About Proximus NXT

Proximus NXT Luxembourg supports all organizations in their digital transformation, by providing holistic ICT & Telecommunication solutions, as well as tailored managed services. With our partners and customers, we co-create opportunities and enable growth in a secure and sustainable manner. As a result of our unique expertise in next-gen IT services, mobile and advanced connectivity, we help our customers achieve their ambitions and realize their vision.

Together with them and our partners we implement sovereign and trusted solutions that make people work smarter.– www.proximusnxt.lu

Your mission:

We are looking for a skilled o to lead the technical evaluation of Apache Pulsar as a next-generation event streaming platform for a multi-cloud and hybrid (sovereign cloud + on-premises) environment. The ideal candidate will design, deploy, and benchmark Pulsar clusters across CleverCloud (sovereign) and AWS (public cloud), assess protocol compatibility with existing Kafka and JMS workloads, and validate geo-replication, fault tolerance, and observability capabilities. This role requires strong experience with distributed messaging systems, cloud-native architecture design, and the ability to produce clear architectural assessments and recommendations that drive business decisions.

Key Responsibilities
• Architecture Design & Evaluation: Lead the architectural assessment of Apache Pulsar as a replacement/extension of the existing Kafka-based event streaming platform. Design target-state architectures for intra-cloud, cross-cloud, and hybrid (cloud ↔ on-premises) messaging scenarios.
• Pulsar Deployment & Configuration: Deploy, configure, and operate Apache Pulsar clusters on CleverCloud (managed) and on-premises (containerised on OpenShift/Kubernetes).
• Performance Benchmarking: Design and execute performance tests at varying message sizes (KB/MB), load levels (messages/second), and tenant configurations. Compare results against existing on-premises Kafka cluster baselines (non-prod and prod).
• Protocol Compatibility Assessment: Evaluate Kafka-on-Pulsar protocol handlers (Starlight for Kafka, StreamNative KSN) and Pulsar JMS support. Prototype migration of an existing Kafka application and a JMS-based application to Pulsar with minimal code changes.
• Geo-Replication & Hybrid Architecture: Configure and validate Pulsar geo-replication between sovereign cloud (CleverCloud), public cloud (AWS), and on-premises clusters. Assess latency, disaster recovery, and cross-environment read/write scenarios.
• Observability & Monitoring: Integrate Pulsar monitoring with existing corporate tools (Dynatrace, Grafana, Splunk, OpenSearch). Validate that operational visibility is sufficient for production readiness.
• Multi-Tenancy Validation: Configure and test Pulsar's native multi-tenancy model (tenants, namespaces, access policies) to confirm suitability for a shared-cluster enterprise model.
• Documentation & Recommendations: Produce clear POC findings, architecture decision records (ADRs), and a final recommendation on Pulsar's suitability for the corporate event streaming platform.
• Collaboration: Work closely with the Kafka operations team, solution architects, application teams (for migration prototyping).
• Training & Knowledge Sharing: Contribute to the knowledge base; provide technical guidance to stakeholders on event streaming architecture patterns and Pulsar capabilities.

Your profile:

Required Skills & Experience
• 5+ years of experience in Cloud Architecture, distributed systems engineering, or messaging platform design and operations.
• Strong hands-on experience with Apache Kafka (architecture, operations, tuning, troubleshooting) - understanding of brokers, partitions, replication, consumer groups, and Kafka Connect.
• Knowledge of Apache Pulsar (architecture concepts: brokers, BookKeeper, topics, tenants, namespaces, geo-replication) or demonstrated ability to ramp up quickly on comparable distributed systems.
• Experience designing multi-cloud and hybrid architectures - integrating services across public cloud (AWS), sovereign cloud, and on-premises infrastructure.
• Proficiency in containerised deployments - Kubernetes/OpenShift, Helm charts, container lifecycle management.
• Proficiency in scripting and automation - Python, Bash, and infrastructure-as-code tools (Terraform, Ansible).
• Experience with monitoring and observability tools - Dynatrace, Grafana, Splunk, or OpenSearch.
• Experience with CI/CD and GitOps - GitLab CI, ArgoCD, or similar; understanding of GitOps principles for infrastructure configuration.
• Understanding of messaging protocols - JMS 2.0, Kafka protocol, AMQP - and experience with protocol bridging or migration.
• Knowledge of Apache Pulsar protocol handlers - Starlight for Kafka (DataStax), StreamNative KSN, Pulsar JMS - or willingness to evaluate them hands-on.
• Knowledge of event-driven architectures and stream processing (Kafka Streams, Flink, Spark Streaming).
• Experience with Confluent Kafka or other managed Kafka/streaming solutions.
• Performance testing methodology - ability to design, execute, and interpret load tests for distributed systems.
• Strong analytical and documentation skills - ability to produce concise technical assessments, architecture descriptions, comparisons, and ADRs.
• Excellent problem-solving and communication skills.
• Strong communication skills (oral/written) to interact effectively with both technical teams and management stakeholders; capable of making presentations and driving architectural discussions.
• Ability to work in an international/multicultural environment.
• Ability to work both independently and collaboratively within a team.

Nice-to-have
• Experience with CleverCloud or other European sovereign cloud providers.
• Experience with Redis and key-value store patterns.
• Certifications in Kafka, Kubernetes, or cloud platforms.
• ITIL qualification is an asset.
• Fluency in English (written and spoken) is required; proficiency in any other European language is a plus.
• Available for a fixed-term engagement aligned with the POC timeline (estimated 4–6 months across all phases).

Our offer:

• A professional, stimulating and innovative working environment:

  Joining Proximus Luxembourg means becoming part of a human-sized company while benefiting from the strength, expertise and opportunities offered by the Proximus Group. You will work within dynamic, supportive and collaborative teams, where team spirit, knowledge sharing and innovation play a central role.

• Genuine career opportunities within the Proximus Group:

  You will have the opportunity to develop your career within Proximus Luxembourg and the Proximus Group, both nationally and internationally. Thanks to the diversity of our activities, internal mobility opportunities and an environment that encourages continuous learning, you will be able to strengthen your skills and grow your expertise in innovative fields such as cloud, data, artificial intelligence, telecommunications and emerging technologies. You will benefit from personalized support and tailored training programs to support your professional development.

• An attractive remuneration package and benefits that support your work-life balance:

  Your salary is defined according to a clear salary framework, taking into account your professional experience, skills and seniority. The recruiter will share the applicable salary range with you before the first interview. You will also benefit from flexible working hours with the possibility of teleworking, as well as numerous benefits: meal vouchers, the possibility of a company car, “quality time” dedicated to supporting your work-life balance (4 hours per month), additional days of leave linked to our collective agreement, sports and well-being activities, and much more.

• A company committed to diversity and inclusion:

  Proximus Luxembourg promotes equal opportunities and provides an inclusive environment where everyone can thrive and develop their full potential. Our multicultural teams, representing 34 nationalities, reflect the richness of our company culture.

  As part of the recruitment process, a criminal record extract may be requested. Your personal data is processed in accordance with applicable data protection regulations.