I applied via the email address on the Plaxis vacancies pages and submitted a code sample. Three weeks later I was invited to the office in Delft for an orientation interview with the Manager of Software Engineering and a Senior Software Engineer. The orientation interview was pleasant and much like many interviews (overview of the company, my background, my interest in the company, my skills) with some technical questions to determine what specific sector of the SW department would suit best (custom projects or commercial projects). The initial code I submitted was not discussed, but what was discussed was the next stage of the interview process. If I were invited to the next stage then Plaxis would assign me a coding challenge themselves and set a time limit.
Two days after the orientation interview, I received an invite to the next stage with the completion deadline set for twelve days later. I won't elaborate on the coding challenge content, but the aim is for you to showcase your technical and organisation skills by showing the entire development process you use via commits on github.
By the deadline date I emailed Plaxis back with the url for my github repository. Four days later I received an email that I would not be progressing to the third round of interviews, with feedback on why I was not going to be selected. The feedback was quite useful and inline with Plaxis' ethos of only selecting candidates that meet the requirements in all categories: Organisation, Code quality, maintainability, desire to learn, etc.