Basically, the choice of topics is free for the students. Of course, you can also edit a topic specified by a professor or a company. Most students find it easier to work on a topic of their own, as they are more likely to be enthusiastic about it. In general, one should have some interest in the topic of one’s own bachelor thesis, since one has to spend several months dealing with this subject intensively. In addition, you should pay attention to whether the topic is relevant to the subject and if there is enough research literature. If the topic has already been extensively researched, then one should consider whether there is still an interesting question that has not yet been addressed.
One should also refrain from topics for which there is very little research literature, since these probably have too little substance for a scientific qualification work. Furthermore, when choosing the topic, it must be ensured that you find a suitable supervisor at your own university or your own department. Many professors only supervise topics that are very close to their own research profile and show little open to devious topics.
What do I have to take into account in the bachelor thesis if I want to show a focus on my diploma?
If you want to focus on the certificate, then you need to do all of your undergraduate studies in order to do so. This means that you have to attend the courses of the main focus, complete the practical semester in this area and align the topic of your Bachelor thesis accordingly. If all coursework and examinations have been done in this area, it can be noted on the diploma.