Users have no control over data they uploaded or that was collected about them on the internet as nearly all of the data is stored in databases of different platforms. The companies behind these platforms often hide the details on how the data is used behind long terms of use agreements. This way, users often do not know that their data is used to create extensive profiles about them. These profiles allow third-party companies to target advertisements to specific user groups. The profiles can also be used to manipulate and spy on users as well as to spread fake news. The potential abuses and the problems concerning the lock-in on platforms-which forces users to stay on existing platforms-are a problem and need to be addressed.

Before presenting a solution, the thesis provides insights into Personal Information Management. The reasons why information management is important are discussed. Various types of personal data are explained to showcase the amount of data that is relevant to users. Afterwards, different tools, their problems, as well as shortcomings, are presented.

The next chapter explains the idea of Personal Data Stores (PDS), starting with their historical development and the definition of essential terminology. Reasons, why PDS could be a solution to the problems mentioned earlier, are presented. Afterwards, a short market analysis of current PDS solutions is done. Next, the thesis reviews the necessary key technologies in the areas of semantics, as well as authorization and authentication. They are followed by a compilation concerning the regulatory framework of PDS solutions.

Finally, an application that uses an existing PDS solution as the backend is developed. During the development, several problems with the existing PDS solution occurred. The encountered problems are analyzed and are solved in a prototype PDS solution that gets designed and implemented.

The aim of this bachelor thesis was to provide an overview over the topic Real-Time-Communication in the web. This thesis is directed at students and developers in the IT-Business, thus the basics of data transfer in the internet are only explained shortly. Current state of the art technologies like Polling, Long-Polling, Server-Sent-Events and Web-Sockets will be explained and compared to each other. The focus of this thesis is WebRTC, thereby the background and development of the WebRTC standard will get explained. Additionally, the differences in architectures compared to classical systems get highlighted. After the theoretical basics have been explained the focus shifts to problems that will occur in a real life setting, whereby the goal is to explain the problems and offer solutions to fix them. Another focus lies on the connection establishment, whereby the process of establishing an WebRTC-connection is called signaling. Because signaling is not standardized the most common practices and techniques get explained. Especially the topic of Hole-Punching, the process which is used to find a path between the two participants will be described. With the learned concepts a prototype will be presented. Overall there will only be a short oversight over the application of WebRTC, whereby some points as the Session-Description-Protocol-Objects will be explained in detail. It will be analyzed for what scenarios WebRTC is suited or not suited.

The aim of this bachelor thesis is to demonstrate a modern way of implementing a web appli-cation with Angular using an practical example. As this thesis is designed for students and developers from the IT sector, the focus will be on advanced concepts like dumb components and smart components, as well as the basics for less familiar topics.At the beginning of this thesis the current status of the project components that shall be refactored is analyzed. After that the advantages and disadvantages of the current solution are elaborated. Based on the findings, the goals of the new implementation as well as the advantages and disadvantages are discussed. The focus of this thesis are design patterns for web developement using Angular. The basics, as well as advanced topics are discussed. With the techniques, possible pitfalls are shown and solutions for them are presented that get applied in an enterprise context.Using a practical szenario the usage of the presented design patterns will be presented. Thereby the transition from theoretical knowledge to practical skills will be created.