It would be easy to simply confirm that you've worked with someone and had no problems with each other. But a letter of recommendation should make the reader feel that you truly believe in that person and that it's a real opportunity to work with them.
4. Explain to the reader your relationship with the person concerned.
In the body of the letter, briefly describe how you came to work rcs data europe together. This will contextualize your relationship and help the reader understand that your recommendation comes from a real interaction with the candidate.
5. Explain what impressed you most
Companies and schools aren't just looking for a list of skills. They want someone who will fit into the environment and get along with their peers. You can then share your personal impressions of the candidate, on topics that go beyond practical experience. It's also a way to show that the candidate still has room for improvement and isn't afraid to learn.