DoorDash IOS Engineer interview questions

Recruiter call then a live coding interview. Live coding interview consists of adding features to an app. You get started code and some instructions. You add the functionality while explaining your thought process.

Recruiter reached out on LinkedIn, quick intro call - background, past projects, why DoorDash. A few high-level iOS questions (UIKit, Core Data), nothing deep. Then got the take-home, took ~5 hours - extend an Xcode project, load & display JSON data. Kept it modular. Tech phone screen with an iOS engineer - mostly take-home discussion, (why you structured things a certain way and trade-offs) Some Swift follow-ups (structs vs. classes, GCD, memory management). Know your take-home inside out. Onsite had 4 rounds - 1st was coding on an existing project, debugging + extending functionality. 2nd was live coding, LC medium-hard, focus on performance & clean code. System design was an iOS architecture problem - scalability, state management, API design. Last was behavioral - teamwork, past challenges, handling conflicts. Key is to be sharp on Swift, system design, debugging. Mocked with ex-DoorDash engineers at Prepfully - helped a lot. Got the offer!