Financing or partly financing studies through small jobs harbors carries certain drawbacks that students should take into account in advance:
Further information on legal issues relating to short-term student employment can be found under hib | University Information Office in Karlsruhe.
A good option that can also have a positive influence on your studies is finding a job as a student research assistant, known as a "HiWi" in Germany. Due to the department's size, there are many institutes that require research assistance. This way, you can enhance your academic studies while earning money at the same time!
The Centre for Information and Consultancy (ZIB) at the KIT annually publishes an annual Information Brochure