Apache Cassandra Experts in Berlin
matched in minutes from vetted, available specialists with the power of AIHire experts who design distributed data models, tune clusters, and keep Cassandra stable under heavy write loads. Get specialists for replication, repair, and multi-node operations, with fast, precise matching to vetted, available freelancers.
Meet FRATCH Experts in Berlin, who have recently used Apache Cassandra
Wolfram Knan
Last position:
AI / Machine Learning Engineer (Projects & Applied AI) at UNIVERSITÉ PARIS 1 PANTHEON-SORBONNE & LIORA
- Designed and implemented a hybrid recommendation system (content-based + collaborative filtering)
- Built end-to-end ML pipelines including data processing, feature engineering, model training, and evaluation
- Developed RAG-based LLM systems using LangChain and vector databases for semantic search and knowledge retrieval
- Established MLOps workflows with MLflow for experiment tracking, versioning, and deployment readiness
- Implemented deep learning models (computer vision & classification) using PyTorch and TensorFlow
Nune Isabekyan
Last position:
Fractional CTO at OpsWorker
OpsWorker turns Kubernetes alerts into root-cause analyses, on top of the monitoring a team already runs. I lead the technical side: the agent architecture, the AWS infrastructure it runs on (fully inside EU regions), and the engineering decisions behind it, read-only in the cluster by default, human in the loop for judgment. The stack underneath: Amazon Bedrock and Bedrock AgentCore, agents built with the Strands Agents SDK, the Claude and OpenAI APIs, and the Kubernetes API.
Ola Van Dunen
Last position:
IT Lecturer
- IT training in theory and practice for IT specialists in application development and system integration
Qaiser Abbasi
Last position:
Freelance Lead DevOps Engineer at Schwarz Gruppe Produktion
Bootstrapping a CloudOps team and building a multi-cloud provider backend for a low-code Internal Developer Platform (IDP) with env zero
Introducing user story mapping, ADRs, milestones, and backlog management
Designing and developing core APIs, setting up CI/CD pipelines, OpenTofu/Terraform scripts
Representing and communicating the team with third-party stakeholders (e.g. env zero)
(Cross-)team coaching on DevOps, software design, Terraform, Golang, and agile practices
Fady Kuzman
Last position:
Senior Software Developer / Tech Lead at Specific Objects Technologies GmbH
- Project 1: Multi-Tenant SaaS Platform: Data Integration & Pricing Management
- Objective: New development of ELT pipeline (replacement for Java 6 legacy), integration of heterogeneous source systems (CSV, Excel, Email, external DBs), event-sourcing for complete auditability, multi-tenant architecture for tenant-capable data processing
- Challenge: Processing millions of records daily, audit compliance, data isolation between different tenants
- Solution: Stakeholder workshops for requirements analysis, event-driven architecture with Axon Framework and Apache Kafka, AWS services (EC2, S3, Lambda, SQS, API Gateway) for cloud integration, PostgreSQL with tenant-specific schemas for multi-tenant data isolation, REST API design with Spring Boot for external system integrations, comprehensive testing strategy (JUnit, Spring Test, Postman, PACT, ArchUnit)
- Results: ELT performance improved from 30+ min to 1-5 min; 2-3 hours daily saved through workflow automation; 10-20 hours/week saved through event-sourcing auditability; 100% audit compliance; secure multi-tenant data isolation for 10+ tenants
- Project 2: Multi-tenant CRM System Modernization
- Objective: Migration of CRM system (20+ years PHP/MySQL) to Java microservices, Domain-Driven Design implementation, establishment of Test-Driven Development, multi-tenant-capable SaaS architecture for multiple customer tenants
- Challenge: Remodeling complex business logic, no existing test culture, scalable tenant management with data isolation
- Solution: Comprehensive testing strategy (JUnit, Spring Test, Postman, PACT, ArchUnit), multi-tenant architecture with tenant-specific databases, REST API design with Spring Boot for cross-tenant integration, Kubernetes and Docker for container orchestration
- Results: 2× performance improvement; deployment time reduced from 40+ min to 5-7 min; migration without production outages; scalable multi-tenant solution for 15+ customer tenants
- Technologies: Java, Spring Boot 3.x, Angular, Apache Kafka, AWS (EC2, S3, Lambda, SQS, API Gateway), PostgreSQL, Axon Framework, Kubernetes, Docker, GitLab CI, REST API
Christian Richter
Last position:
Freelance Data Engineer at Ingenieurbüro Christian Richter – Data, Cloud & Container
- Contributed to over 20 successful projects
Dirk Ulrich
Last position:
Developer at Future Training & Consulting GmbH
Training course with exam for Spring Certified Professional.
- Environment: Spring Boot 3, Spring Framework 6, IntelliJ
Eli Romm
Last position:
Senior Backend Engineer at Bettermile
- Backend services development in Kotlin with Spring Boot using AWS CDK.
- Design and architecture of new features.
Henning Petersen
Last position:
Backend Systems Development at Deutsche Bank/DWS/Morgenfund
- Developed backend systems for the DWS Investment App, a white-label investment solution (robo-advisor), and an investment solution for institutional clients.
- Java 8-17, Kotlin, Spring Boot, Spring MVC, OpenAPI 3.0, JPA, JDBI, Oracle, Hazelcast, JXLS, Apache POI, Apache PDFBox, Apache Kafka & Avro, Active MQ, Elasticsearch, React Native, Spock Test, IntelliJ IDEA, Kubernetes, Helm, Microservices/Netflix-Stack, TeamCity, Splunk.
- Kanban team, continuous integration.
- Migrated existing applications from Deutsche Bank's private cloud environment to Azure as part of a carve-out.
Mario Ellebrecht
Last position:
Developer and Consultant at Freelancer
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Statistics of experts using Apache Cassandra
Aggregated from the professional profiles of matched freelancers.
Experience
20 years
Position duration
3 years
Positions per freelancer
14
Top business areas
Information Technology, Product Development, Business Intelligence
Top industries
Information Technology, Professional Services, Education
Certification focus areas
Information Technology, Product Development, Quality Assurance
Bachelor's degree or higher
86%
Master's degree or higher
43%
Certifications per freelancer
2
Most common languages
German, English, Spanish
Speak two or more languages
100%
Based on our profile pool as of 30 Aug 2026.
Daily rate distribution
The chart shows how the daily rates of freelancers in this technology in Berlin are distributed, based on recent contracts on our platform. Each bar covers a rate range — its height shows how many freelancers charge within that range.
Average rates of experts in Berlin using Apache Cassandra
Rates are based on recent contracts and do not include FRATCH margin.
The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 30 Aug 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
About the technology
Distributed data
Apache Cassandra is built for systems that must keep writing even when traffic spikes or nodes fail. It stores data across multiple machines and uses replication to keep services available. Companies choose it for event data, product catalogs, messaging, IoT feeds, and other workloads that need steady write performance.
Where it fits
It is often a good fit when horizontal scaling matters more than complex joins or ad hoc reporting. Common choices include:
- high-volume event ingestion
- user activity timelines
- time-series storage
- global applications with regional traffic
Skills that matter
Strong Cassandra specialists know data modeling first. They design tables around queries, not around normalization habits from relational systems. They also understand consistency levels, partition keys, replication, compaction, and how to avoid hot partitions.
Ecosystem
Work around Apache Cassandra usually includes CQL, drivers, monitoring, backup routines, and cluster repair tools. Teams may also need help with Kubernetes, cloud infrastructure, and surrounding services that feed or read from Cassandra. In Berlin, these specialists often support product teams that need remote collaboration but can also join on-site workshops when the data model needs fast decisions.
When to hire
Bring in freelance expertise when a cluster is growing, slow, unstable, or hard to operate. It also helps when a team is migrating from another datastore, reviewing a schema, or fixing read and write patterns that no longer scale. Specialists are useful for audits, incident recovery, and hands-on knowledge transfer.
What good looks like
A strong Cassandra professional makes trade-offs clear and practical. They can explain why a design works, show how it behaves during node loss, and document backup, repair, and recovery steps. Good work leaves the system easier to run, not just faster on paper.
Frequently asked questions
The facts hiring teams ask for most often when it comes to Apache Cassandra.
Apache Cassandra is used for distributed workloads that must stay available while handling large write volumes. It fits event streams, activity data, messaging, IoT feeds, and other systems that need fast writes across several nodes. Teams choose it when uptime and scale matter more than relational joins.
Cassandra is not a replacement for every relational database. PostgreSQL or MySQL are usually better when you need joins, transactions across many tables, or flexible ad hoc reporting. Cassandra is stronger when the data model is query-driven and the main challenge is spread-out, reliable writes.
A company should bring in Apache Cassandra expertise when cluster behavior is unclear, write latency is rising, or the schema no longer matches the access pattern. It is also a smart move during migrations, recovery work, or before a launch that will put real pressure on the data layer. A specialist can spot design issues early and reduce operational risk.
A strong Apache Cassandra professional usually knows data modeling, CQL, replication, and cluster operations. Useful adjacent skills include Linux, cloud infrastructure, containers, monitoring, backup strategy, and Java or Python for driver-based access. In many projects, event-driven architecture and stream processing also come up.
Cassandra projects that touch production systems usually need someone who has already run clusters, not just read the documentation. Simple query changes may be handled quickly, but data model redesign, repair strategy, and consistency tuning need deeper hands-on work. The more critical the workload, the more useful proven operational experience becomes.
Yes, Apache Cassandra work is often done remotely because most tasks involve design reviews, cluster analysis, and application changes. Berlin teams may still want on-site time for architecture workshops, incident reviews, or handover sessions. Clear communication matters, especially when the team mixes English and German in daily work.
Ask how the freelancer models data for specific queries, handles partition design, and thinks about consistency. A strong Cassandra specialist can explain replication, repair, backups, and failure scenarios in plain language. Good candidates also share the trade-offs behind each choice instead of promising a one-size-fits-all setup.
Apache Cassandra is the full project name, while Cassandra is the common short form people use in conversation and search. Some people also say Cassandra DB, but the official name is Apache Cassandra. When you evaluate a freelancer, the important part is real experience with the distributed database itself, not the label they use.
The average hourly rate of freelancers in Berlin, Germany who have used Apache Cassandra in their recent projects is 100 €, which corresponds to a daily rate of about 800 € based on an 8-hour working day.
Of the freelancers in Berlin, Germany who have used Apache Cassandra in their recent projects, 86% hold at least a Bachelor's degree and 43% hold at least a Master's degree.
On average, freelancers in Berlin, Germany who have used Apache Cassandra in their recent projects have 20 years of professional experience, with a single engagement typically lasting around 3 years.
The most common languages among freelancers in Berlin, Germany who have used Apache Cassandra in their recent projects are German (100%), English (100%), and Spanish (20%).
The most common industries among freelancers in Berlin, Germany who have used Apache Cassandra in their recent projects are Information Technology (100%), Professional Services (60%), and Education (50%).
The most common business areas among freelancers in Berlin, Germany who have used Apache Cassandra in their recent projects are Information Technology (100%), Product Development (100%), and Business Intelligence (70%).
Main locations of FRATCH Experts, who have recently used Apache Cassandra
Our freelancers and interim experts are at home across the DACH region — available on-site in the major business hubs or fully remote. Choose a location to discover matched specialists, local market insights and up-to-date availability.
Countries:
Berlin 
Hamburg Munich Cologne Frankfurt Stuttgart Dusseldorf Leipzig Dortmund Essen Bremen Dresden Hanover Nuremberg Request a free demo
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Philipp Thomaschewski
FRATCH CEO
