Senior Engineer: Generally speaking, the examination is theory plus practice. You can't take the advanced exam until you get the intermediate level for two years. Generally, it is for technicians, and the advanced certificate itself is of little use. Some factories will appropriately subsidize some money for advanced certificates, but they are generally very small.

Technician: Generally speaking, the test is theory+practice+thesis, but also PLC and frequency converter. Technicians can't take the exam until they reach the advanced level for two years. Technicians are qualified to guide and educate people below senior level, while senior level is not qualified. It will be much easier to find a job with a technician's license and the salary will be higher. Some companies will also give this card some subsidies, but not much.

Originally, both of them were very valuable, and they would get a big salary increase if they joined the company. However, many companies in society don't pay much attention to certificates (because the labor department rarely checks people who work without certificates), so companies often choose those who are undocumented and have rich work experience (because they are cheap and easy to use).