CRED Mobile App Development Interview Questions & Answers
Curated interview practice questions with answers. These are practice scenarios, not a verified list of past interview questions.
About CRED hiring for Mobile App Development roles
CRED is an Indian fintech platform that rewards members for paying credit card bills and offers products such as CRED Pay, rent payments, CRED Mint and CRED Garage. Its engineering and analytics teams focus on payments, rewards, risk and app experience. It hires for software engineers, SDETs, data analysts and data scientists.
For Mobile App Development roles, this CRED practice set focuses most on Testing, Performance and CI/CD (6), App Store and Play Store Publishing (5), Flutter State Management and Architecture (5), React Native Navigation, State and Native Modules (4). It has 3 easy, 20 medium, 7 hard questions, so you can start easy and work up to the harder ones.
Company type
Fintech
Headquarters
Bengaluru, India
Main India offices
Bengaluru
CRED Mobile App Development interview process
Online assessment or assignment
Technical round (coding or SQL)
Problem solving or design round
Hiring manager round
Typical pattern based on public candidate experiences. Rounds vary by role, team and year.
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01
What is App Store Optimisation and what can a developer influence?
App Store Optimisation improves an app's visibility and conversion in store search. Key factors are the app title, subtitle or short description, keywords, long description, screenshots, preview videos, ratings and reviews. Developers influence it by keeping app size small, crash rates low and performance high, since store algorithms consider quality signals, by adding in-app review prompts at good moments, and by supporting localisation for regional languages.
02
A global Redux store causes the whole app to re-render on every small change. How do you fix it?
Components are probably selecting large parts of state or creating new objects in selectors. Select only the fields each component needs with useSelector, memoise derived data with createSelector, and keep state normalised. Move server data to RTK Query or TanStack Query and local UI state back into components. Verify improvements with the React profiler, checking which components render after each action.
03
Your Flutter codebase mixes setState, Provider and get_it randomly across screens. How would you clean it up?
Agree on one approach with the team, for example Riverpod for app state and setState only for local widget state, and document examples. Migrate gradually, starting with the most buggy or most changed features, and write tests before moving logic. Add lint rules and pull request checklists so new code follows the standard. Avoid a big-bang rewrite that blocks feature work for weeks.
04
Deep links open the app but land on the home screen instead of the product page. How do you debug it?
Check that the link configuration maps the URL path to the right screen name, including nested navigators, and that path parameters match. Verify verified link setup on both platforms: assetlinks.json for Android and the associated domains entitlement plus the site association file for iOS. Test with adb shell am start and xcrun simctl openurl. Also handle links when the app is cold started versus already running.
05
Parsing a 10 MB JSON file freezes the Flutter UI for two seconds. How do you fix it?
JSON decoding is CPU-bound and runs on the main isolate, blocking frames. Move it to a background isolate with Isolate.run(() => parseProducts(jsonString)) or compute. Also consider whether the API can paginate or return less data, and parse lazily. Test in profile mode with DevTools performance view to confirm the frame time improvement, since debug mode exaggerates slowness.
06
Users get logged out randomly. The access token refresh seems to fail sometimes. What could be wrong?
A common cause is a race condition: several requests receive 401 at once and each triggers a refresh, so later refreshes use an already rotated refresh token and fail, logging the user out. Fix it by allowing only one refresh at a time and queueing other requests until it completes, then retrying them with the new token. Also check device clock issues, token expiry settings and secure storage read failures.
07
What is app signing and why must you protect the keys?
Signing proves the app comes from you and that updates are from the same developer. On Android, you sign uploads with an upload key and Play App Signing re-signs with the app signing key held by the store; a lost upload key can be reset, but losing a self-managed app key meant you could never update the app. On iOS, signing uses certificates and provisioning profiles. Store keys in a secure vault and CI secrets, never in the repository.
08
How do you decide which devices to test on for an Indian user base?
Use analytics from the existing app or market data to identify the most common manufacturers, OS versions, screen sizes and RAM levels among your users. Cover a budget device with 3 to 4 GB RAM, a mid-range phone, a recent flagship, an older OS version you still support, and at least one iPhone and tablet. Use cloud device farms for wider coverage and add devices that generate many crashes.
09
How do you set up CI/CD for a cross-platform mobile app?
On every pull request, run lint, formatting checks, unit and widget or component tests. On merge, build signed Android and iOS release artifacts using CI services such as GitHub Actions, Codemagic, Bitrise or EAS Build, with signing keys stored as secrets. Use fastlane or EAS Submit to upload to internal testing tracks and TestFlight. Automate version numbers, generate release notes and run smoke tests with Maestro.
10
Why are you interested in this mobile developer role at our company?
Connect your skills to the role honestly. For example: your app serves millions of users in tier 2 and tier 3 cities, and I have focused on performance for budget phones and slow networks in my projects. I have shipped two cross-platform apps to both stores, and I want to work where release quality and user experience matter at scale. I also like that your team uses Flutter, which I enjoy and want to master.
11
Integration tests pass locally but fail randomly in CI. How do you make them reliable?
Flaky tests usually come from timing assumptions, shared state, network dependence or slow emulators. Replace fixed delays with waiting for specific conditions, mock or stub network calls with predictable responses, reset app data between tests, and use stable selectors like keys or test IDs instead of text that changes. Give CI emulators enough resources, retry only as a temporary measure, and track flaky tests separately to fix them.
12
You are designing a large Flutter app for a bank with 30 developers. How do you structure it?
Split the app into feature packages in a monorepo managed with Melos or pub workspaces, plus core packages for networking, design system, analytics and security. Pick one state management approach, such as Bloc for strict traceability, with clear layer boundaries. Use code generation consistently, enforce lints and architecture tests in CI, and assign feature ownership. Add integration tests for critical journeys and strict security reviews for storage and network code.
13
Tell me about a time you improved app performance in a cross-platform app.
Situation: our React Native order history screen took three seconds to render and scrolled poorly. Task: make it smooth. Action: I profiled with React Native DevTools, replaced ScrollView with FlashList, memoised rows, moved date formatting into the API layer and switched images to a caching library. Result: render time dropped below 600 milliseconds, and frame drops nearly disappeared on budget phones.
14
What is a Stream in Dart and how is it used in Flutter?
A Stream delivers a sequence of asynchronous events, such as real-time database updates, location changes or WebSocket messages. You listen with listen() or await for, and transform with map, where and debounce from packages. Single-subscription streams allow one listener; broadcast streams allow many. In Flutter, StreamBuilder rebuilds UI on each event. Always cancel subscriptions in dispose to prevent leaks.
15
How would you migrate a large React Native app from JavaScript to TypeScript?
Enable TypeScript with allowJs so both coexist, start with a relaxed tsconfig, and convert shared code first: API types, models, utilities and navigation param lists. Then convert screens feature by feature, tightening strict options gradually. Add type checks to CI so new files must be TypeScript. Avoid using any to silence errors; use unknown and narrow. Track progress and celebrate milestones to keep momentum.
16
Why do Flutter apps need a state management solution beyond setState?
setState works for local UI state inside one widget, but shared state like the logged-in user, cart or settings must be read and changed by many screens. Passing it through constructors becomes messy, and rebuilding large trees hurts performance. State management libraries separate business logic from UI, make state testable, rebuild only widgets that depend on changed data, and give a clear, predictable flow of updates.
17
Write a custom hook that fetches data with loading and error states.
Identify which elements truly need platform-specific behaviour: navigation transitions, back gestures, date pickers, switches and dialogs. In Flutter, use adaptive constructors like Switch.adaptive or Cupertino widgets based on Theme.of(context).platform. In React Native, many components are native already, and Platform.select handles differences. Keep shared business logic and most layout common, and limit platform branches to a component library so they stay manageable.
19
A user reports that they cannot find your app in the store on their old phone. Why could this happen?
The app may not be available for their device because the minimum OS version is higher than theirs, the device lacks a required hardware feature declared in the manifest, the app is not released in their country, or the device architecture is excluded. Check the device catalogue in Play Console and the deployment target on iOS. Decide whether supporting that segment is worth lowering requirements.
20
Your app must show live delivery partner location on a map. How would you design it?
The partner app sends location updates every few seconds through a foreground service to the backend, which publishes them to a real-time channel like WebSockets or Firestore documents. The customer app subscribes only while the tracking screen is open and smoothly animates the marker between points. Throttle updates, reconnect on network changes, and fall back to polling. Stop tracking when the delivery completes to save battery.
21
After an API call finishes, the app throws an error about using BuildContext across async gaps or setState after dispose. How do you fix it?
The user left the screen before the Future completed, so the widget was unmounted. Before using context or calling setState after await, check if (!context.mounted) return; or if (!mounted) return; in State. Better still, move async logic out of widgets into a state management layer that the UI listens to, and cancel subscriptions or timers in dispose so no callbacks run on a dead widget.
22
How would you structure the folder layout of a medium-sized cross-platform app?
Organise by feature rather than by type: features/auth, features/cart, features/profile, each containing UI, state logic and data code. Keep shared pieces in core folders such as core/network, core/storage, core/theme and core/widgets or components. Put configuration for environments separately. This keeps related code together, makes ownership clear and lets features be moved into packages later. Enforce the structure with lint rules and code review.
23
The Firestore bill is growing fast because of too many reads. How do you reduce it?
Find screens that listen to large collections or re-read data on every rebuild. Paginate queries with limits, listen only to needed documents, detach listeners when screens close, and avoid starting listeners inside build methods. Denormalise data to reduce reads per screen, cache data locally with offline persistence, and use aggregate count queries instead of reading all documents to count. Monitor usage per collection.
24
What is InheritedWidget and how does Provider build on it?
InheritedWidget lets descendants read data efficiently via context and rebuild when it changes, which is how Theme and MediaQuery work. Writing it by hand is verbose. Provider wraps InheritedWidget with a simpler API: ChangeNotifierProvider exposes a ChangeNotifier, and widgets use context.watch to rebuild or context.read to call methods without rebuilding. It is simple and suitable for small to medium apps.
25
A React Native list of 2000 items scrolls slowly and shows blank areas. How do you fix it?
Use FlatList or FlashList rather than ScrollView with map. Provide a stable keyExtractor, memoise row components with React.memo, avoid inline functions and heavy computation in renderItem, and use getItemLayout or fixed item sizes where possible. Tune windowSize and maxToRenderPerBatch, compress and cache images with a library like expo-image, and test a release build, since dev mode is much slower.
26
Users lose their place in a long Flutter form when they get a phone call and the app is killed in background. How do you fix it?
The operating system may kill the app process in background, and in-memory state is lost. Save draft form data to local storage, such as shared_preferences, Hive or a SQLite table, as the user types with a short debounce, and restore it when the screen opens. Flutter's RestorationMixin and restorationScopeId can restore simple UI state like scroll position and text fields. Clear the draft after successful submission.
27
QA reports the app becomes slower the longer it is used. How do you investigate?
This suggests a memory leak or growing work. Reproduce by repeating a flow many times while profiling memory and CPU. Look for listeners, timers or subscriptions that accumulate, caches without limits, lists that keep growing, or screens kept in the navigation stack. Fix by disposing resources, limiting cache sizes and replacing screens instead of pushing endlessly. Confirm memory returns to baseline after fixes.
28
The app takes six seconds to start on low-end phones. How do you improve it?
Measure cold start on a release or profile build and trace what runs before the first frame. Defer non-critical SDK initialisation such as analytics and ads, avoid large synchronous storage reads and network calls before showing UI, load the first screen with cached data, and lazy-load other features. In Flutter, keep main() light; in React Native, use Hermes and inline requires. Use a native splash screen to avoid a blank screen.
29
Tell me about an app you published and what you learned from real users.
Situation: I published a notes app with a friend and got about 2,000 installs. Task: improve ratings stuck at 3.6. Action: I read every review, found users disliked losing notes when switching phones, added cloud backup and a clear onboarding screen, and fixed two crashes from Crashlytics. Result: rating rose to 4.4 in two months. I learned to prioritise what users actually complain about over features I assumed they wanted.
30
Write a GitHub Actions workflow that runs Flutter tests on every pull request.
Tips to crack the CRED Mobile App Development interview
Learn how credit card bill payments, UPI and rewards economics work, as CRED's products are built around them.
Pay attention to product design and user experience, which CRED is known for emphasising in its app.
For analyst roles, practise cases on member engagement, reward cost and credit risk segmentation.
Keep a one-minute story ready for every project on your CV: problem, your part, tools, result.
Practise the hard questions on this page aloud; CRED interviewers usually ask follow-ups on your first answer.
Frequently asked questions
How many rounds are there in the CRED Mobile App Development interview?
Candidates usually go through 4 stages: Online assessment or assignment; Technical round (coding or SQL); Problem solving or design round; Hiring manager round. The exact rounds change with the role, team, location and your experience, so confirm the process with the recruiter.
Which topics should I prepare for the CRED Mobile App Development interview?
This practice set leans on Testing, Performance and CI/CD (6), App Store and Play Store Publishing (5), Flutter State Management and Architecture (5), React Native Navigation, State and Native Modules (4). Revise those first, then practise explaining one or two of your own projects end to end, because most CRED interviewers ask you to walk through real work.
Are these the exact questions asked at CRED?
No. These are curated practice questions that match the skills and difficulty usually tested in fintech interviews like CRED's. They are not a leaked or verified list of past questions.
Where does CRED hire Mobile App Development professionals in India?
CRED has large teams in Bengaluru. Openings and locations change often, so check the CRED careers page and filter by city and experience.
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