You need to submit your CV, cover letter, academic certificates (including your diploma!), and two reference letters. Afterwards, they schedule a 30-minute video call to ask questions about the role and the company. If they like you, they send you a take-home assignment to complete within about 72 hours. If that goes well, you must travel to Castelldefels at your own expense (no reimbursement) to present the take-home project, followed by spending another hour in a small room completing an additional task. All of this takes place within just a few days, so you need to be fully available. Afterward, they disappear and only get back to you three weeks later to let you know whether they liked you. Throughout the entire process, they never mention any details about the contract.