Best way to get a job in Switzerland is answering job offers, then unsollicited applications, then knowing the right person.
Of all the applications you send, 40% will be completely useless because opening was filled, postponed, cancelled or whatever.
After one month without hearing from an application you send, consider it finished and you are out.
If you see a new job offer who is exactly like another one you answered at least one month ago
without getting any answer or being said the job is not opened anymore but will soon, you should reapply.
They also consider that after a month your situation has completely changed and the information you provided
are out of date and maybe you got another job.
To send a message on LinkedIn to a person not in your network (e.g. to ask for advice about a job opening in his team),
check out his profile and list his groups. Then find a group where you can freely enroll. Once in the same group, you can send him a message.
Cover letter structure: 1/6 where you explain how you link to the company, 1/3 where you state your motivation
for the company (or department, lab... The smallest unit) and the opening (except for unsollicited applications),
explaining you want to do your job well. Speak about competitors. Ask questions.
1/2 about you and them, stating what are your plans once hired.
On your resume, put at the beginning 3 key points you want the recruiter to remember about you. These and your technical skills should be adapted for each application you send.