Technical leadership

1.You lead the mobile platform group for a bus ticketing app. Supporting the oldest Android version costs the team about a week per quarter. Product worries about losing riders. What do you bring to the decision first?

2.Your team agreed to drop iOS versions older than two releases back. Three months later, a large school district customer says many of its tablets cannot update. What do you do?

3.You decide to drop Android versions below a certain level in the spring release. What makes the rollout fair to users still on those versions?

4.An engineer on your team wants to drop an old OS version so they can use a new UI framework. Analytics show 9 percent of weekly users on that version. What is the right response?

5.Leadership asks you for a standing rule on when the app drops OS versions, so the question stops coming up every quarter. What do you propose?

6.You recorded the decision to raise the minimum iOS version in a short decision note. What should the note include so it is useful a year from now?

7.Two weeks after you dropped an old Android version, support tickets show a hospital's staff on locked-down devices lost access. Nobody checked enterprise device fleets. What do you do as the lead?

8.Your product manager wants to keep a very old OS version because one sales deal depends on it, but supporting it blocks a security fix. What do you do?

9.You become the mobile tech lead for a recipe app. The iOS and Android teams built the same meal planner with different data models and different bugs. What is a good first step?

10.iOS and Android engineers in your app keep shipping the same feature with different analytics event names. Product cannot compare the platforms. What fixes this best?

11.The Android lead and the iOS lead disagree on how the new offline cart should resolve conflicts, and both have built prototypes. You are the staff engineer for mobile. What do you do?

12.Your company's Android app is a full release behind iOS on features. The Android team is smaller and morale is low. What is a sound move?

13.You want iOS and Android to stop drifting on new features. Which practice works best over time?

14.The iOS team wants to adopt a new architecture pattern. The Android team has no plans to change. Does that need your involvement as mobile lead?

15.A bug in the login flow exists only on Android because the two teams read the spec differently. Each says the other team read it wrong. What do you do?

16.The iOS and Android teams have separate standups and planning, and rarely talk. You want them to coordinate without heavy process. What is a good first change?

17.Your app ships on a two-week release train. A feature team asks to hold the train three days for their feature. Other teams have fixes ready. What do you do?

18.App store review has been taking up to four days lately, and your release train assumes one day. A partner launch depends on the next release. What is the right action?

19.A server change went live while the app release that needed it sat in store review. Users on the old app saw errors for two days. What do you change as the lead?

20.Your release manager role rotates among senior engineers each train. The same three people keep doing it because others say they are too busy. What do you do?

21.Feature teams keep merging large changes the day before the release branch is cut. The branch is often unstable. What fix should you push for?

22.Your iOS release is rejected by app review for a privacy wording issue on the day you planned to ship. Marketing has a campaign set for tomorrow. What do you do first?

23.Your app ships every two weeks. A team wants a weekly train for faster feedback. Store review and phased rollout already take a week. How do you approach it?

24.A hotfix is ready for a bug that affects 2 percent of users. The next train leaves in four days, and a hotfix needs its own store review. How do you decide?

25.Your new release is at 10 percent rollout. Crash-free sessions drop from 99.8 to 98.5 percent within an hour. You are the release lead. What do you do first?

26.During a crash spike, five engineers jump into the incident channel with theories, and nobody is sure who decides. You are the most senior mobile engineer there. What do you do?

27.A crash spike traced to a third-party analytics library update. The team that bumped the version did not test it on older devices. What should the follow-up focus on?

28.After a crash incident, the follow-up review produced 14 action items. Two months later, only one is done. What do you do as the lead?

29.A crash spike hit only one phone model with a vendor-modified OS. Product asks if this means the release process is broken. How do you answer?

30.Your team paused a rollout because of a crash spike, then found the bug. An engineer wants to resume the rollout at 50 percent right away with the fix. What do you say?

31.An on-call mobile engineer did not page you during a crash spike at night because they did not want to bother you. The incident lasted three extra hours. What do you do?

32.A crash spike reached the company leadership channel before your team posted anything. A director is asking what is happening. What should you do now?

33.Your app's crash rate creeps up slowly over six releases, with no single spike. Nobody owns it. What do you do?

34.Your company wants a new companion app. Leadership asks whether to build native, use a cross-platform framework, or reuse web views. What do you deliver?

35.Your team chose a cross-platform framework a year ago. Now two screens need heavy native camera work and the framework struggles. An engineer says the whole choice was a mistake. What do you do?

36.Two senior engineers argue in a design review over a cross-platform framework, each citing benchmarks. The review has run 90 minutes. You own the decision. What do you do?

37.You decide to adopt a cross-platform framework for new features but keep old screens native. How should you record the decision?

38.Leadership hears that a rival app shares 90 percent of code across platforms and asks why your team shares only 30 percent. What is the best response?

39.A cross-platform pilot on one simple screen went well. A team lead wants to move the whole app over this quarter. What is the right next step?

40.You are asked whether to rewrite the app's networking layer in shared code. You are unsure if the gain is worth it. What is a reasonable way to decide?

41.A year after adopting shared business logic across platforms, the team says debugging is harder. The original decision note listed this as a risk. What do you do?

42.You own the app's cold start budget of 1.5 seconds. A feature team adds a software development kit (SDK) that adds 400 ms at launch. They ship tomorrow. What do you do?

43.Your app size grew 40 percent in a year, and install conversion is falling in markets with slow networks. Teams say size is someone else's problem. What is a good first step?

44.A product director wants a large animation library for a holiday campaign, adding 8 MB to the app. Your size budget allows 2 MB of growth per quarter. What do you do?

45.You set startup and size budgets. Six months later, teams treat them as your personal rules and argue each breach with you. What should change?

46.A continuous integration (CI) check now fails builds that exceed the startup budget. A team says the check is flaky and blocks merges for no reason. What do you do?

47.Product asks why the app's startup budget matters when users rarely complain about it. How do you make the case?

48.You review a feature team's design that loads three new modules at launch, which would break the startup budget. The team lead is senior to you. What do you do?

49.Your team cut cold start from 2.4 to 1.6 seconds over a quarter. How should you report it so the work keeps getting support?

50.Eight feature teams contribute to one shopping app. Shared code like navigation and networking has no clear owner, and changes break other teams. What do you propose?

51.A feature team in your shared app keeps adding code to the main screen module because it is the fastest place. Other teams copy them. What is the best fix?

52.A team in your shared app wants to add a state management library used nowhere else. They say it will save them time. What do you do?

53.Build times in your shared app have doubled in a year. Each team blames the others. As mobile lead, what do you do first?

54.A feature team broke checkout in your shared app by changing a shared date helper. Their tests passed. What should the follow-up focus on?

55.Code review norms in your shared app differ by team: some approve in minutes without reading, others take days. Quality and speed both suffer. What do you push for?

56.A small platform team supports twelve feature teams in your app and is overwhelmed by requests. What do you help them do?

57.A feature team wants to run an experiment that changes the app's bottom navigation, which every team relies on. They have not told the other teams. What do you do?

58.Two feature teams in your app both want the top slot on the home screen. Their product managers cannot agree, and both ask you to decide. What do you do?

59.You are writing a design doc for moving your app's image loading to a new cache. Who should review it before you build?

60.A senior engineer leaves 40 comments on your design doc, most of them minor style points, and two raise serious risks. What do you do?

61.In a design review, a mid-level engineer raises a concern about offline behavior that you think is wrong. Others go quiet. What do you do?

62.Your design doc for a new sync layer is 30 pages. Reviewers have not started after a week. What should you do?

63.A design review for a new feature flag system ends with no decision. Two options remain, and the meeting is out of time. What should happen next?

64.You want the mobile team to write design docs before big changes, but engineers see them as busywork. What helps the habit stick?

65.A design doc from another team proposes a deep link scheme that conflicts with one your team shipped last year. The review is tomorrow. What do you do?

66.You are the decision owner for a design. One respected engineer still disagrees after a full discussion. Everyone else supports it. What do you do?

67.You lead a multi-quarter project to rebuild your app's checkout. Halfway through, it is clear the full scope will not fit. What do you do first?

68.A product manager asks your team to add home screen widgets this quarter. Your team is already committed to a migration the business needs. What do you say?

69.You are planning a year-long effort to modularize your app. How should you sequence it?

70.Your manager asks you to commit to a launch date for a new offline mode. You have many unknowns. What do you give them?

71.A sales leader asks your mobile team to build a custom feature for one large customer. It does not fit the product plan. What is the right response?

72.Three months into adding accessibility support across your app, you find the work is twice the size you estimated. What should you do?

73.Your team has a quarter for a dark mode project. Design wants every screen polished. You estimate the core screens take the whole quarter. What is the best plan?

74.Your app's old networking code causes many bugs, but product sees no reason to spend time on it. How do you make the case?

75.Your team wants to spend a full quarter paying down technical debt. Product is opposed. What is a better proposal?

76.An engineer wants to replace your app's dependency injection system because they find it awkward. It works and causes few bugs. What do you say?

77.Your team paid down a big piece of debt in the app's local database layer. How do you show it was worth it?

78.A team in your shared app adds a quick hack to meet a launch date and promises to fix it later. You have seen many such promises go unkept. What do you do?

79.The chief technology officer asks why mobile feature work has slowed over two years. You believe debt is a big reason. What do you bring?

80.You lead a migration of every screen in your app to a new navigation library. Twelve teams own screens. How do you start?

81.Your navigation migration is 80 percent done. The last 20 percent sits with teams that keep deferring it. What do you do?

82.You are migrating the app's analytics to a new pipeline. Product teams fear losing data. What makes the migration safer?

83.A team asks to be exempt from your migration to the new image loader because their screen is special. What do you do?

84.Halfway through migrating your app to a new build system, a major bug in the new system appears. Teams want to stop. What do you do?

85.You are planning a migration of your app's login to a new identity provider. Who must you involve early?

86.You are the only person who knows how the app's release pipeline works. You are going on leave in a month. What do you do?

87.Every hard technical decision in your mobile team waits for your review. Work is slowing. What should you change?

88.A mid-level engineer on your team wants to lead the next big feature. They have never led before. What is a good way to support them?

89.An engineer you mentor ships a design you would have done differently, but it works and meets the goals. What do you do?

90.A strong engineer on your team keeps fixing other people's bugs late at night. The team relies on them and is not learning. What do you do?

91.You are asked to mentor a new staff engineer who joined from a web background. What is a good first step?

92.You delegated the app's accessibility work to a senior engineer. A month later, a product manager asks you directly for the status. What do you do?

93.You notice you are on every escalation path for the mobile team: releases, incidents, design, and hiring. What is the best next step?

94.Your team's offline mode launch is three weeks away, and you now think it will slip by two weeks. What do you do?

95.Your project is slipping because a backend team keeps missing dates for an API your app needs. What do you do?

96.Your launch is at risk, and your manager wants to tell leadership everything is on track until you are sure. What do you do?

97.Your team delivered a project two weeks late. The cause was a dependency nobody tracked. What should the retrospective focus on?

98.A project you lead is on track, but a key engineer is leaving in two weeks. What do you do?

99.A product leader keeps adding small requests to your app project mid-quarter. Each seems minor, but together they threaten the date. What do you do?

100.A designer wants a custom transition that stutters on older phones. The designer is firm. What do you do?

101.Your manager decides to rewrite the app in a new framework. You believe it is a mistake. What do you do?

102.You shared your concerns about the rewrite, and your manager still goes ahead with it. What do you do?

103.A product manager asks your team to skip a crash fix to ship a new feature on time. The crash affects 1 percent of sessions. What do you do?

104.A more senior engineer proposes a caching design for your app that you think will cause stale data bugs. What do you do?

105.The security team asks your mobile team to add certificate pinning before the next release. Your team thinks it will break users on some corporate networks. What do you do?

106.You want all teams in your app to adopt a new accessibility checklist. You have no authority over them. What works best?

107.You want to raise code quality across your mobile team. Which approach works best?

108.A team in your app ignores the agreed logging standard, and logs are hard to search during incidents. You have raised it twice. What next?

109.You want the mobile organization to adopt a shared crash triage rotation. Teams see it as extra work. How do you build support?