Apache Flink Experts in Germany

Collin K.

Lead Fullstack Developer

Kempen

Last position:

Software Architect / Fullstack Developer at Equity Bytes

Built an international e-commerce platform for a multi-vendor marketplace for digital assets from scratch. Designed and operated cloud native architectures at enterprise scale.

Designed and operated a highly scalable microservice and serverless architecture
Built the complete cloud infrastructure with Terraform + AWS CDK in AWS
Provisioned ECS/EKS clusters (Fargate), Application Load Balancers (reverse proxy), and Lambda functions
Observability & tracing with CloudWatch, DataDog, Prometheus, and Grafana
End-to-end setup with DataDog (formerly AWS CloudWatch), Prometheus, and custom Grafana dashboards
Integration of advanced metrics (including ORM mapper) and distributed tracing with Jaeger
Robust backup and disaster recovery strategies
RDS Postgres backups and hourly snapshots
Read-only, asynchronously synchronized replicas with automated master failover in emergencies
Minute-level rollback capability through versioned Docker images on ECS and Git-based CI/CD pipelines
Created CI/CD pipelines with GitHub Actions for automated multi-stage deployments (Dev, Testing, Prod)
Integrated Stripe for international payment processing
Built a marketplace payment system with multiple parties and payout routines
Used Algolia for high-performance real-time search of digital assets on the platform
Federation of services with GraphQL and Hasura
Later migration to GraphQL Mesh
Test Driven Development (TDD) - unit, integration, and E2E testing with Jest, Vitest, and Playwright
Used Next.js / React for modern frontend applications in the nx monorepo
Enterprise security architecture & access control
Integration of JWT tokens with Auth0, OAuth, OIDC, IP guards, BOLA protection, and secret vaults
Authorization concepts with RBAC, ABAC, and native Postgres Row-Level Security (RLS)
Built internal microfrontends with Retool for fast prototyping and operational business processes

Technologies: ABAC, AWS CDK, AWS CloudWatch, AWS ECS, AWS EKS, AWS Fargate, AWS RDS, AWS S3, Algolia, Auth0, DataDog, Docker, GitHub Actions, Grafana, GraphQL, GraphQL Mesh, Hasura, JWT, Jaeger, Java, JavaScript, Jest, Kotlin, Kubernetes, Monorepo, Next.js, OIDC, Playwright, Postgres, Postgres RLS, Prometheus, RBAC, Redis, Retool, Serverless, Stripe, Terraform, TypeScript, Vitest

Domenic V.

Independent Technology Leadership. I Work at Both Ends, the Org and the Code. Ex-{Spotify, Ebay}

Last position:

Founder at VOS Ventures Tech UG

Working as independent / interim / fractional CTO / engineering director, technical leader, builder, coach. Select achievements:

Fractional CTO for a music-tech startup. Helped unlock further funding by providing the technical strategy and plan behind their vision and pitch deck, then executed it: vision to a working beta, 0 to 1, on time and on budget against that plan.
AI automation for a compliance business. An annual research process — days of a person working through spreadsheets and checking websites by hand, so costly it had been abandoned for years — now runs automatically every month and takes about an hour to review. Stale or missing data became current data, twelve times a year.
An AI development autopilot. Agents take an approved ticket, implement test-first, verify against a running system and open a pull request. An AI committee reviews on various categories and provides risk assessments based on my specs. Nothing merges without a human.
Coaching and sparring for engineering leaders. Developing engineering managers was most of my job as a director; I now do it one to one.

Fabian C.

GIS & AI Architect – Computer Vision and Geospatial Data

Kalkar

Last position:

Senior GIS Developer at Transport & Logistics

Development of a route planner for incident communication.

Development of the REST API
Set up a patch system for maintaining the routing graph
Expansion of the testing infrastructure
Performance and memory optimization (JMeter, JFR)

Technologies: Java 21, Spring Boot, JGraphT, Flyway, MapStruct, Caffeine, ShedLock, JMeter, Kubernetes, JFR

Jens O.

Freelance Java Developer / DevOps Engineer

Leipzig

Last position:

Freelance Java Developer / DevOps Engineer at Unpublished defense company

Extension of OSGi modules in a complex communication solution
Debugging communication with Wireshark and remotely in the JENS test environment
Migration of tests from TestNG to JUnit 5 with Mockito and AssertJ
Updating vulnerable dependencies and improving code quality
Changes to the Vaadin frontend
Increasing test coverage

Aweem A.

Senior Java Developer

Last position:

Senior Java Developer at Folio3

Architected, developed, and maintained scalable backend services using modern Java (17/21), Kotlin, and Spring Boot for high-traffic, performance-critical platforms.
Served as a technical leader for complex initiatives, taking features from inception through deployment, and implementing runtime validation layers using advanced LLM APIs with secure guardrails.
Optimized PostgreSQL schemas and query efficiency at scale, drastically reducing data retrieval latencies and ensuring cross-service transactional consistency.
Spearheaded continuous improvement in development processes, designing comprehensive unit and integration testing frameworks that drove test coverage from 50% to over 90% via JUnit, Spock, and Mockito.
Partnered extensively with cross-functional product and data squads to define API boundaries, design interfaces, and ensure rapid, high-confidence CI/CD release cycles.

Marie R.

HR & Compensation Consultant, Fractional VP People

Last position:

HR & Compensation Consultant, Fractional VP People at Marie Richter HR Consulting

Interim VP People at Malt, Vay, Sharpist, Unleashed Capital, and i2x
Project work with Zalando, DeepL, DoorDash, Bilfinger, Aiven, Contentful, Gorillas, Tier Mobility, Moss, Oetker Digital, and Uberall on compensation & benefits, performance & talent management, people operations, and HR business partnering
Implementation of HR & compensation tools at DeepL, Flink, HeyJobs, Yager, Finoa, and Unleashed Capital
Hourly HR & compensation consulting for Lufthansa Innovation Hub, Finanzguru, DigitalService des Bundes, ifok, Vialytics, Leonyte, ACELR8, and Refokus

Ibrahim H.

Senior Full Stack Engineer | Cloud & AI Agent Engineer

Last position:

Senior Full Stack / AI Engineer at Punktum Digital GmbH

Context: Healthcare and laboratory teams required faster document analysis, treatment-planning support, and reliable AI workflows for MR/VR-assisted operations.
Contribution: Built the AI healthcare platform, model/agent workflows, VR-glasses deployment platform, REST APIs, Next.js/React interfaces, and CI/CD pipelines.
Impact: Delivered a production-ready AI product foundation that improved clinical document review, supported laboratory automation, and made VR fleet deployment manageable across environments.

Tech: TypeScript, Next.js, Node.js, React, Java, Spring Boot, Python, PyTorch, TensorFlow, Docker, PostgreSQL, OpenAPI, GitLab, GitHub Actions.

Selvaraj K.

Senior Full Stack & Cloud Architect

Wiesbaden

Last position:

Senior Full Stack & Cloud Architect at HCLTech

Led end-to-end implementation of the Miles and More Credit Card Service integrating with TSYS systems on Microsoft Azure
Architected secure, scalable APIs and microservices using Spring Boot, Camunda, and Apache Kafka (Confluent Platform) for real-time event streaming and process automation on Azure Kubernetes Service
Managed full development lifecycle of the credit card system on Azure Cloud including fraud detection, payment processing, account management, and Kafka-based event-driven data pipelines
Designed and implemented Kafka Connect integrations and Schema Registry for seamless data flow between microservices and legacy systems
Introduced Agile best practices, improving team efficiency by 30% and reducing project delivery time
Directed and mentored a team of 15+ developers fostering a collaborative, cloud-first, and innovation-driven culture
Managed client relationships achieving 95% satisfaction and securing follow-up projects through consistent delivery excellence
Designed and deployed BPMN/DMN models in Camunda for complex business workflows and automation
Configured Camunda Engine with advanced features such as error handling, RPA integration, and multi-version deployments
Integrated Camunda and Kafka-based messaging with core banking systems ensuring high availability and data consistency
Managed multi-database schema configurations on Azure and optimized system performance for high throughput and fault tolerance
Designed and implemented cloud architecture patterns on Azure focusing on multi-region resilience, data sovereignty, and event-driven scalability for critical financial workloads

Anton K.

Head of Overall Technical Integration NSC / Hadoop Cloud Development

Munich

Last position:

Head of Overall Technical Integration NSC / Hadoop Cloud Development at IABG

Head of overall technical integration NSC (National Secure Cloud, project with approx. 60 employees).
Technical integration of all subprojects into one product, definition of interfaces and basic components of a cloud including hardware, technical architecture of the IABG platform.
Development of a Cloud Management Platform (CMP) capable of creating private/mixed clouds of any complexity based on a textual description with one click or interactively.
CMP also includes the complete hardware management lifecycle.
Kubernetes, OpenStack and Hadoop are used as the foundation.
The management layer includes Harbor, Gitea, Longhorn, Keycloak, Rancher and Jenkins, which are configured automatically.
Private cloud can run any customer workloads, including a full Hadoop layer with HDFS, Spark, MapReduce, Mesos, HBase and around 20 additional ML/DL technologies.
Hadoop worker clusters can also be installed automatically without Kubernetes on bare metal or commodity hardware.
OpenStack with Nova, Neutron, Ironic, Swift, Cinder, Ceph.
Development of a Java application Rudi: SOAP, REST, containers, DB.
Technologies: Kubernetes (K3s, Rke2, Minikube, Harbor, Gitea, Jenkins, Longhorn, Keycloak, Rancher), OpenStack (Nova, Neutron, Keystone, Swift, Ceph, Cinder, Sahara, Magnum, Kayobe, Kolla, Bigrost, Ironic), Hadoop (HDFS, Ambari, Solr, Livy, Ranger, YARN, Tez, HBase, Kafka, Hive, Zookeeper, MapReduce, Spark, Oozie, Flink), virtualization (Kubernetes (K3S), VMware, Oracle), scripting (Ansible, Puppet, Juju, Shell, Groovy, Gradle, Maven).

Umar M.

Senior AI Architect & Engineer

Last position:

Senior AI Architect & Engineer at Freelancer / Self-Employed

Consulting, design and architecture of SaaS platforms with a focus on automation, data analysis and cloud deployment
Definition of the target architecture and management of the entire development lifecycle from implementation to production operation, including stakeholder alignment
Design, architecture and implementation of a multi-tenant SaaS platform
Development of scalable data and machine learning pipelines (Batch & Streaming) for order and business data
Development of AI models for data analysis (KPI calculations, forecasts) and integration into data pipelines
AI-supported processing of customer inquiries (delivery status, invoice, cancellation, complaint) to automate customer service
Development of APIs, microservices and dashboards with Python for data-driven applications
Cloud deployment on AWS and infrastructure-as-code automation with Terraform; containerization with Docker and Kubernetes
Development of CI/CD pipelines for automated deployment with GitLab CI and governance of deployment processes
Implementation of monitoring dashboards with Grafana to monitor services and ML pipelines
Implementation of security and compliance requirements (GDPR-compliant data handling, logging), including identity and access management and role-based access control

Stephan S.

Senior Data/ML Consultant & Technical Lead

München

Last position:

Senior Data/ML Consultant & Technical Lead at Jolin.io

Role: Software Engineer & Applied Mathematician (Mathematical optimization for scheduling; duration: 1 months; team setting: Team of 2, remote; technologies: JuMP, Julia, Pluto, Svelte, JavaScript, TypeScript, JetBrains Space, Terraform, Nomad)
Role: Software & Cloud & Web Engineer (Building scalable data science compute cluster from scratch; duration: 11 months; team setting: Team of 1, on-site; technologies: Terraform, Kubernetes, k8s ingress, k8s services, k8s RBAC, k8s networking, k3s, etcd, S3, DNS, certificates, Julia, Pluto, JavaScript, Tailwind, Astro, npm, Parcel, Preact, MUI, JWT, AWS SQS, AWS RDS, Python, GitLab, GitHub)
Role: AI & Web Engineer (Custom ChatGPT service; duration: 1 months; team setting: Team of 2, remote; technologies: Python, Poetry, LangChain, Tailwind, ChatGPT API, Flask, FastAPI)
Role: Architect & Data Engineer (Central datalake setup and ingestion; duration: 9 months; team setting: Team of 5, remote; technologies: Infrastructure-as-code, AWS CDK, Python, Boto3, PySpark, AWS Glue, IAM, S3, ECS, Fargate, Lambda, Apache Hudi, DeltaLake, Databricks, GitHub, Jira, Miro)
Role: Software Engineer (PoC Julia migration of scikit-decide; duration: 1 months; team setting: Team of 2, remote; technologies: Python, Julia, GitHub)

Daniel C.

Founder & Managing Director

München

Last position:

Founder & Managing Director at BotCraft GmbH

Building the company with a focus on connectivity for IIoT and Industry 4.0, iRPA/process automation, advanced robotics and smart systems, sensors and services
Project management and software architecture for IoT gateway development (since 2020) with protocol translation, IT/OT convergence and GRC
Developing RPA bots for automating and monitoring industrial processes with an agent-based AI approach (since 2020)
Implementing unsupervised clustering and anomaly detection for time series data in big data streaming pipelines (since 2021)
Introducing a Docker-based release train for OTA updates with DevSecOps and CI/CD (since 2018)

Jens G.