Applied online. Got an interview call, scheduled to talk with a senior engineer over on the team. Had a nice chat with him going over some projects and technical challenges faced. Was given a take-home challenge on HackerRank.

The test was to create a small Android app with some particular specifications and instructions. There is only a problem and no guideline as in how to solve it or what the design should look like. The candidate has to come up with the UI/UX, the right architecture for implementing this, and making tradeoffs.

The challenge was to finish the app within 4 hours, which in my opinion is extremely difficult to finish. They want you to write a production-level app with the right coding practices, good architectural pattern (MVP, MVVM, etc.), coming up with the right UI/UX behavior, and making sure the app has the minimal number of bugs and works according to the specifications they ask for.

The app itself has a lot of moving components, and there is no guideline as in how you should achieve this. Example: they say "save this somewhere," but they don't mention how to save this. Should you save this in the app cache? A database? Shared preferences? Write to a file? Save it in the bundle? Make a POST API call and submit it? Since the challenge is only for 4 hours and you have to make tradeoffs, you will probably decide to choose the fastest and cleanest way, but according to them, it might not be the "right" way to do it.

Overall, it was a waste of 6-7 hours in interviewing here. They ask their candidates to spend 2 hours of phone call (1 hr + 1 technical phone screen + 4-5 hr take-home challenge) and in the end, reject you for not writing a production-level app in 4 hours. Reading the last review here from June 2017 with someone else having a similar experience looks like these guys won't be filling that position anytime soon with such interview standards.

Feedback to Instacart (if you guys are reading this):

• Have some sort of rubric of what you guys are looking for instead of leaving everything to the candidate. At least tell them what the least things that are required are, some nice-to-have things, etc., in the app.
• If you are going to ask someone to spend 6-7 hours of their time in an interview process, at least give more detailed feedback on what went wrong.
• 4 hours is not enough time to write that app, so either give more time or relax some of the restrictions.

Take-home challenge