After applying I was sent a link to a Hackerrank test within a couple days and asked to complete the test within a week. The test was fairly simple, based on different algorithms which you can practice with the Hackerrank courses. After a couple days I was emailed to say I'd received a Skype interview. The interview was arranged for the next day so I didn't have much notice. The interview was a simple competency based interview, and the interviewer was very patient and understanding through the process. Almost immediately afterwards I was invited to a recruiting day, again this was with very short notice. The day was split into a group exercise in the morning, which involved designing a new product for Skyscanner, and interviews in the afternoon. There were two interviews: a cultural interview - assessing your work ethic and such - and a technical interview - assessing how you tackled a challenge that was posed by the engineers. This was the last stage of the process.