Development of a service facade in Java that encapsulates core business logic

• Improve scalability and technical performance of the API and its latency
• Draft architectural decisions together with Tech Leads and explore new technologies
• Coaching and supporting junior developer

• Introduction to Software Engineering
• Software Modelling with UML
• Design und Architectural Patterns
• Course can be found online: (URL on request)

Implement performant transaction data importer for popular third-party payment providers (Golang)

• Design and implement low-latency data import service in Golang using AWS Lambda to import user transaction data from third-party providers
• Conception of data warehouse solution & data visualisation w/ AWS Quicksight

• Extending existing VAT ID checker to support new request types using Golang
• Add Cloudwatch metrics to monitor AWS Lambda function
• Implement web frontend for customers with React.js

Implementing and evaluating Dynatrace Synthetic ActiveGate for hosting Private Locations on SAP multi-cloud platform

• Create Terraform deployment for Synthetic ActiveGate targeting multiple IAAS providers (AWS, Google Cloud, Ali Baba Cloud, Azure)
• Run performance benchmark with statistical evaluation and hardware sizing recommendations
• Integrate Synthetic ActiveGate into existing multi-cloud environment
• Improve existing Dynatrace Golang client

Description: Helping search-guard to implement latest features, helping with releases

Tasks:

- Evaluate and implement k8s operator to host secure Elasticsearch

- Implement product features

- Help with Elasticsearch know-how

As a backend engineer I was involved in the development of SoundCloud?s search systems. Furthermore I was also responsible for operating SoundCloud?s production systems including large Elasticsearch clusters.

• Improvement of the indexing throughput and search latencies: the lead time for a full reindex was cut down from 6h to 1h, the search latency improved by 4x for the 95th percentile.
• C.f. Blog Post: URL on request
• Rollout of the Search systems to multi-data zones
• Development of an automated process to run search regression tests and creation of a gold standard dataset
• Migration of the existing HTTP based indexing pipeline to a reliable Kafka based version
• Implementation of a Sentinel based ?Exact Match? search
• Improvement of stop words usage in search
• Creation of A/B Test proposals and RFCs

Based on a Cloud-native architecture for processing events in realtime, the platform allows to find interesting interconnections inside the companies data lake using diverse similarity services. The standard approach is using well known linguistic methods which allow to find textual similarities inside the document space.

• Creation of Microservice Blueprints using the Spring Cloud Netflix Stack (Eureka, Cloud Config, Hystrix und Feign)
• Development and review of existing Microservices based on Spring Boot Cloud Stream. Analysis of the existing architecture regarding the scalability and reliability
• Conception and development of a way to test the Microservices with all the needed infrastructure services via Docker-compose
• Deployment and provisioning of needed Docker images (Queuing, Streaming, Storage)
• Gathering functional and non-functional requirements in order to design domain-specific components
• Introduction of a CI/CD process using Jenkins pipelines

The main goal of this project was to modernize the IT infrastructure of the bank as part of the new IT agenda. Also due to a new regulation the bank has to serve as a data provider for administrative authorities.

• Development of a Cloud-native infrastructure altogether with implementing domain-driven data pipelines
  • From the infrastructure perspective Kubernetes was introduced. 
  • The new application architecture was based on messaging using Apache Kafka. 
  • The implemented data pipeline were separated via their corresponding domain.

Originally the data import caused a direct down time of the system. Likewise the customer support had no means to enter customer data and to respond adequately to customer requests.

• Development of a customer service frontend and development of a rolling update mechanism for the interruption-free data import in production (Festanstellung)
  • The interruption-free import was implemented with the help of Hazelcast, an in-memory solution. 
  • The customer service frontend was based on Spring Web MVC und Thymeleaf.
  • Furthermore a CI/CD pipeline was developed using Jenkins.

The main task of this project was to replace the old monolithic architecture with a Microservice oriented architecture in order to speed up the development of new business use cases.

• Development of a Microservice platform for real-time processing and implementation of data pipelines
• Altogether with a CI/CD pipeline on top of Kubernetes, the old-fashioned ETL pipelines were replaced by stream pipelines based on mApache Kafka.

The payment platform in use should be renewed in order to be able to cope with the growing customer requests. Therefore a test automaton was created in order to guarantee that the new platform correctly processes the existing use cases / functionalities.

• Creation of a test automaton for the new development of the mass payment platform / SEPA engine
  • Realization of a GUI in order to have a dashboard with all test cases. 
  • Creation of a messaging/integration component which ensured that the messages from the input channel were correctly processed via fetching the processed messages from the output channel and comparing them with the expected result.

MasqueradeIT is a service simulation service which was created for a Daimler project. This project was about to further advance it by implementing various customer features and requests. The service simulator supported SOAP-Webservice via HTTP, JMS messaging via WebSphereMQ and JMS messaging via ActiveMQ.

• The customer features were needed in order to simulate the real backend

Description: Develop software which transformed data of an energy provider (netlist, energy flow etc.) and transferred it to the transparency portal of the EU.

• Implementation of an automated data delivery to the Entso-e.net portal (Transparency portal of the European Union)
  • Development of the GUI, Modelling of the business processes in Camunda BPM and development of the corresponding delegates. 
  • The data mapping was created with JAXB and XSLT transformation files were created with Altova MapForce.

For the development of an ?IOT? pilot project in the area of agriculture an Android based handheld application was implemented. The application contained various different complex screens such as a historical temperature profile and used a push notification service for sensor alarms.

• Implementation of the specified screens
• Integration of a push service
• Release control and management
• Implementation of a asynchronous service layer with rxJava

The existing platform was extended with a new payment format.

• Populate the XSD format from the customer.
• Enhance the internal integration routing.
• Map the new format to the needs of the customer. 
• Develop automated tests and update the CI process accordingly.