Preparation for Korea
Getting a suitable and major-related job in Korea depends all on your Korean ability in terms of Korean work culture (can you handle the hierarchy?) and the Korean language. The Korean work culture is totally different from that of the West.
Separate from your qualifications, working from early in the morning till late in the evening are standard in Korea (unpaid overtime except some companies pay your overtime) and drinking after work with your managers and co-workers are almostf mandatory.
Also you can't leave your work before your boss and you have to be on time in the morning before your boss arrives. These are just a few manners in the Korean working culture. Korean companies prefer business / management / economics or finance majors. It's ok if you majored in another field but it could take perhaps a bit longer before you have a suitable job here.
Like Western companies in an interview Korean companies are looking for candidates with the best first impression. Formal clothes and a neat appearance is obviously important. To stand out from the rest a representative resume is a must. On the Work in Korea page you can find more information about writing the resume. Age matters alot in Korea and the best range to apply for jobs to make a good chance is between 24 - 28 years old.
Most of the Korean men finish their military service when they are around 20 - 23 years old and return to the University to graduate. When they apply for professional career jobs the age is mostly common around 25 - 26 years old. For women, it's similar but can be earlier or even a bit later depending on their private situation. Standard work-finishing time is roughly 20:00 pm - 23:00 pm or even 01:00 am past Midnight! Some companies even have a mattress in their office.