A recruiter reached me. Two days later, I received a request to complete an online assessment with 90 minutes, which included four multiple-choice questions and two coding questions. All the questions were pretty simple. However, my browser was not working properly. After I finished the coding questions, I clicked the 'Run' button, and the browser showed me a 'request timed out' error. I then had to go back to the original link to open it again. After reopening the link, the 90-minute timer had run out. I suggest to future candidates: don't use Safari or any browser with a lot of add-ons, like ad blockers.

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Implement the credit card number verification method. They provide the method; you only have to implement it.