Whenever you are looking for a job first you need to see if the company is offering a job or has an opening for the job that you are qualified for. In this case the first thing you need to do is to research if the companies are hiring and if they’re hiring software engineers. You need to weigh the pros and cons for both companies and see which one matches your best.
For instance I would look at the salary that this one job at each company is paying. If it is not listed on the job ad then I would look on the Internet for the average salaries of this position at this company. Next I would look at the benefits and the job description and see which one would benefit me most.