Rene Hartmann
Verified Expert in Engineering
Software Developer
Edderitz, Saxony-Anhalt, Germany
Toptal member since February 21, 2022
Rene is a goal-driven agile developer with 15+ years of experience designing and implementing successful, scalable, and performing Java-based solutions. He is keen on writing clean and maintainable code and is mainly interested in working with high-performance, scalable, low-latency distributed applications. Rene believes efficient working processes, mentoring, and teamwork are crucial for successfully developing and deploying solutions.
Portfolio
Experience
- Java - 20 years
- Git - 10 years
- Spring - 10 years
- Scrum - 10 years
- Spring Boot - 6 years
- Docker - 4 years
- React - 4 years
- Google Kubernetes Engine (GKE) - 2 years
Preferred Environment
Linux
The most amazing...
...web application I've build is a global trading management app.
Work Experience
Java DevOps Engineer
ING Group
- Developed CI and deployment pipelines and related microservices.
- Created a UI to deploy the company's apps into OpenShift clusters.
- Set up a gateway to make services available to consumers running in different OpenShift clusters.
Senior Java Developer
MediaMarktSaturn Retail Group
- Created and maintained a Spring Boot-based service to orchestrate the shipment process of online orders during the company's critical checkout process.
- Integrated the service into the company-wide microservice architecture and deployed it to the Google Cloud Platform with Kubernetes.
- Persisted shipment data in PostgreSQL and MongoDB and integrated other services via REST and Pub/Sub.
Senior Java Developer
Credit Suisse
- Consolidated the bank's risk data in a central system. Processed data stored in a Hadoop cluster using an in-house cloud platform and data pipeline architecture.
- Designed and developed REST services that enable data extraction to client systems for further analysis.
- Developed a distributed architecture using Spring Boot components to scale the extraction process compliant with the applications' service level agreements.
Senior Java Developer
UBS
- Developed a data distribution application for instrument and client data, amongst all trading applications in the front-office equities IT department. Implemented Java core multithreaded and GC-free low-latency applications.
- Implemented a Spring Boot-based web service for data collection and distribution. Developed T-SQL stored procedures for data persistence.
- Developed the front end with HTML5, Bootstrap, jQuery, and React. Deployed Spring Boot services to CloudFoundry.
Senior Java Developer
Wiley
- Designed and implemented new shared OSGi bundles to extend CMS capabilities and connect to RESTful web services.
- Executed the performance tuning of the back-end mapping components to achieve higher throughput and lower the required CPU time with YourKit, Profiler, JMeter, and VisualVM.
- Identified and solved permanent generation memory errors caused by hot deployments within the OSGi container.
Senior Java Developer
IBM
- Implemented Java core multithreaded front-end and back-end components with several interfaces to other systems based on REST, web services, messaging, and email.
- Designed and developed a dynamic authorization component to let the customer change the application's behavior on an ad-hoc basis.
- Developed a thread pool to distribute performance-intensive asynchronous workloads to several concurrent working threads.
Experience
Git Lock
https://github.com/hartrene/git-lockEducation
Master of Science Degree in Computer Science
Darmstadt University of Applied Sciences - Darmstadt, Germany
Certifications
Java 8 OCP Certificate
Sun Microsystems
Sun Java 1.6 Certified Programmer
Sun Microsystems
Sun Java 1.4 Certified Programmer
Sun Microsystems
Skills
Libraries/APIs
React, jQuery, Node.js
Tools
Git, Jira, GitHub, Camunda BPM, Shell, Google Kubernetes Engine (GKE), Gatling, Postman, IntelliJ IDEA, Helm, RabbitMQ
Languages
Java, XML, SQL, HTML, JavaScript, UML, Web Services Description Language (WSDL), Java 11
Frameworks
Spring, Spring Boot, Hibernate, Bootstrap, Hadoop, Ruby on Rails (RoR)
Paradigms
Microservices, REST, Scrum, Management, Azure DevOps
Platforms
Kubernetes, Linux, DotCMS, JEE, Google Cloud Platform (GCP), Docker, Amazon Web Services (AWS), Red Hat OpenShift, Apache Kafka
Storage
Microsoft SQL Server, IBM Db2, PostgreSQL, MongoDB
Other
Distributed Systems, Communication, Team Leadership, Full-stack, GitOps, DevOps Engineer, Client-server Model, Documentation, Cloud Foundry, Spring Cloud Gateway, Quarkus
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