Gregor Tätzner

This section includes a more detailed description of my projects. I mentioned only points where I contributed a vital part or worked on my own.

Smart Home/HomeAssistant - Spark: Data analytics in the context of smart home networks 

Pattern Recognition, Data Collection and Querying of sensor data in medium sized smart home networks

• Humidity Patterns: https://gtaetzner.de/blog/shower-time
• Data Export and Visualization: https://gtaetzner.de/blog/my-cold-home

XPay: Customizable Prepaid-Creditcard processing platform with multiple large customers

We transformed with a large scrum team a legacy web platform to a modern SPA architecture. I worked together with my team on the front and backend code. In the process we also introduced a Rest-Api as middleware to separate the old core from the new application. Furthermore the entire platform was deployed on AWS in multiple docker containers.

• Responive Javascript SPA frontend with AngularJS 2
• Customer dashboard with multiple widgets and OAuth authentication
• Rest-Api modelled with Swagger, including client sdk generation for AngularJS
• New Java/Spring middleware with SOAP-Adapters
  
• Legacy PHP/Symfony core with SOAP-Api
• Large MySQL database with customer and transaction data
• Main technologies: AngularJS, Protractor, PHP/Symfony, RabbitMQ, Java/Spring, MySQL, AWS, Docker, Python

Lisa Wörterbuch: Large vocabulary dictionary for german and english built with VueJS (http://woerterbuch.lisa-sprachreisen.de/)

I developed together with a data scientist and domain experts an online dictionary. The application has been deployed and maintained on a modern AWS infrastructure by me.

• Complete responsive Javascript SPA frontend with VueJS
• Backend implemented with PostgreSQL and Elasticsearch
• The application included over 10 million translated entries
• Custom ranking algorithm for Elasticsearch
• Main technologies: VueJS 1.0, VueRouter, VueResource, PHP/Laravel, PostgreSQL, Elasticsearch

Conni.net: Social Event App connected to facebook via graph api built with VueJS and PHP

This was a private project by me and a business partner. We developed a social web application for event coordination and evaluated possible business cases.

• Responsive Javascript SPA frontend with VueJS
• Password based user management and Facebook Login with PHP/Laravel
  
• Independend Python 3 Service for cleaning and loading data from Facebook into PostgreSQL
• Main technologies: VueJS 1.0, VueRouter, VueResource, Vueify, PHP/Laravel, Python, PostgreSQL
  

Phojoca.com: Social network for authentic travel experiences

I'm part of a distributed team in germany with the goal to establish a community marketplace for individual travel tours. Currently I'm consulting the team and leading the development efforts on and off.

• Main technologies: Regular LAMP Stack, Trello, WhatsApp

AMSL Linked Data ERM System: Electronic Resource Management for libraries (http://amsl.technology)

AMSL is an open source ERM system funded by the european union. I was part of a small development team to maintain and extend a legacy application for new use cases. The system was notable for it's quirky architecture including RDF data stores and convoluted frontend code. It made quite for an challenging experience.

• Main technologies: PHP/Zend, Javascript/JQuery, OpenLink Virtuoso, SPARQL, RDF