Anatomy of the iOS dev interview
Welcome to the mobile interview playbook.
There aren't many guides detailing the full iOS interview loop even in 2025. Many resources break down a dozen common questions like:
"Can you describe the Model-View-Controller (MVC) architecture?"
... but this is not how an iOS Engineer is assessed today.
The bar is much higher today
A lot more is expected from senior candidates; failing just 1/5 onsite rounds can eliminate your chances.
I've been fortunate to receive many interviews in 2024, so I'd like to share what you can still expect as an iOS engineer in 2025.
This playbook reflects my experience interviewing for mobile roles in NYC and SF. I've been rejected from dozens of companies and have so much to learn. Take my experience and advice with a grain of salt.
The 7 types of mobile engineering interviews
Still as relevant as ever—especially in bigger tech (Meta, Duolingo, Airbnb, Snap). Startups still test DSA, but smaller mobile teams often give the 'mobile-friendlier' coding questions (see spectrum graph below). Either way, phone screen questions are standardized for correctness — a pass/fail format. Like a guard statement that returns early, these questions weed out most candidates before the team invests additional effort.
DSA Questions
Sweet Spot
Platform Specific
DSA Questions
Sweet Spot
Platform Specific
Some teams test algorithms; others focus on iOS or Android frameworks. Correctness is crucial in phone screens, but speed matters too. If you breeze through the first question, expect a follow-up (always assume a phone screen is two parts). Timebox your study sessions- leetcode or general prep, it makes a difference!
Historically, behaviorial interviews were thought to be the easiest round to pass. The format was what you'd expect: "Tell me about a recent ... strong disagreement ... team member, how did you handle it?"
This interview was used to answer:
- are you nuts
- how well do you communicate
- your accountability / can you handle deadlines
- are you a team player
- are you kind
- have you done the job before
Not anymore. For many companies, this interview is either removed or refocused as 'Past Project / Software Design' and/or 'Core Values' interviews.
My guess: behaviorial responses are hard to score. The answers are personal, and candidates lie too often. It's no surprise this interview is falling out of favor.
have you done the job before
Like the old behavioral format, the Past Project Q&A is trying to figure out, 'have you done the job before?'. But this time, instead of asking disparate questions to check off every bucket they want to answer (one question for team work, one question for conflict, one question for juggling timelines), the interview is anchored on the one past project you select, and the same signal gather process is based off this main story. There are huge benefits, but also huge downsides to this evolved interview style. I personally dislike this format because it is booby-trapped for down-leveling candidates. This format is great for hiring commitees because the grading is more deterministic, but as you might imagine, the responses aren't normalized like the old behavioral format. That is, a large code migration for a meal kit startup, is not the same as a leading an org wide migration at Meta.
You're expected to prepare one project that you're proud of and worked on fairly recently (past 2-3 years), ideally something recent and is far more focused. But this format rephrases the question into, 'what is the best job you've done in the last several years?'
It's not completely new, but I only see more non-bigger tech companies adopting this format.