I am a sales engineer. I will only explain my own situation to you.
First of all, I am an employee with a technical background and have engineer qualifications.
Due to the difference between foreign markets and domestic markets, pure sales personnel cannot conduct on-site technical exchanges in many equipment fields. Therefore, technical personnel usually perform sales work, and engineers are required to have basic business communication skills. At the same time, because this kind of position is usually only available abroad, it also requires relatively proficient foreign language proficiency.
Since foreign projects involve a large amount of travel expenses, most overseas sales engineers must have considerable technical support capabilities. So this position is called Sales Support Engineer.
The specific salary package may have a lot to do with the industry you are in and the unit you work for. Of course, it is also directly related to your performance.
Looking at the prospects, this kind of position has development prospects and is very good for young people.