10+ CARS24 Software Developer Interview Questions and Answers

Merge two sorted linked lists into a single sorted linked list without using additional space.

• Create a dummy node to start the merged list

• Compare the values of the two linked lists and add the smaller value to the merged list

• Move the pointer of the merged list and the pointer of the smaller value list

• Continue this process until one of the lists is fully traversed

• Append the remaining elements of the other list to the merged list

Sort an array of 0s, 1s, and 2s in linear time complexity.

• Use three pointers to keep track of 0s, 1s, and 2s while traversing the array.

• Swap elements based on the values encountered to sort the array in-place.

• Time complexity should be O(N) and space complexity should be O(1).

To find the fastest 3 horses out of a group with 5 horses racing at a time, we can use a tournament style approach.

• Divide the horses into groups of 5 and race them against each other. This will give you the fastest horse in each group.

• Take the winners from each group and race them against each other. The top 3 horses in this final race will be the fastest 3 overall.

• Keep track of the results and compare the timings to determine the fastest 3 horses.

Output-based questions in JavaScript using browser APIs

• Example 1: Write a script that uses the Geolocation API to display the user's current location on a map

• Example 2: Create a program that uses the Web Audio API to play a sound when a button is clicked

• Example 3: Develop a web page that uses the Canvas API to draw a simple animation

Designing a system to support localization in a mobile app

• Use resource files to store localized strings for different languages

• Implement a language selection feature for users to choose their preferred language

• Utilize localization libraries or frameworks to streamline the process

• Consider cultural differences when localizing content, such as date formats and currency symbols

To debug lag on a screen, analyze code, check for memory leaks, optimize rendering, and use profiling tools.

• Analyze code to identify any inefficient algorithms or operations causing lag.

• Check for memory leaks that could be impacting performance.

• Optimize rendering by reducing the number of draw calls, optimizing shaders, and minimizing overdraw.

• Use profiling tools like Xcode Instruments or Android Profiler to identify performance bottlenecks.

The app I recently worked on is a social media platform for sharing photos and connecting with friends.

• The app follows a client-server architecture, with the client being the mobile app and the server handling data storage and processing.

• The client side is built using React Native for cross-platform compatibility.

• The server side is implemented using Node.js with a MongoDB database for storing user data and photos.

• The app uses RESTful APIs for communication between the client ...read more

The event loop is a mechanism in programming that allows for asynchronous execution of code.

• The event loop is a key component in JavaScript's runtime environment, responsible for handling asynchronous operations.

• It continuously checks the call stack for any pending tasks and executes them in a non-blocking manner.

• The event loop ensures that the program remains responsive by allowing other code to run while waiting for asynchronous tasks to complete.

• Example: setTimeout() funct...read more

Implement a Springboot service to intercept HTTP requests.

• Create a Springboot application with necessary dependencies.

• Implement a custom interceptor by extending HandlerInterceptorAdapter.

• Override preHandle and postHandle methods to intercept requests and responses.

• Register the interceptor in the WebMvcConfigurerAdapter configuration class.

LRU cache is a data structure that stores the most recently used items, discarding the least recently used items when full.

• Use a doubly linked list to keep track of the order of items based on their usage.

• Use a hash map to quickly access items in the cache.

• When a new item is accessed, move it to the front of the linked list. If the cache is full, remove the item at the end of the list.

HashMap is a data structure that stores key-value pairs and allows for fast retrieval of values based on keys.

• HashMap is implemented using an array of linked lists or a balanced tree to handle collisions.

• It uses a hash function to map keys to indices in the array.

• Example: HashMap map = new HashMap<>(); map.put("key", 123); int value = map.get("key");