Zscaler Softech Senior Devops Engineer Interview Questions, Process, and Tips

To check if a number is a power of 2, we can use bitwise operations.

• A power of 2 has only one bit set to 1, so we can use the bitwise AND operator to check if the number is a power of 2.

• If n is a power of 2, then n & (n-1) will be 0.

• For example, 8 (1000 in binary) is a power of 2, and 8 & 7 (0111 in binary) is 0.

Sort a stack without using another data structure

• Use recursion to pop the top element and insert it at the bottom of the remaining stack

• Repeat until the stack is sorted in ascending order

• Time complexity: O(n^2), space complexity: O(n) due to recursion

Check if array has continuous increasing and decreasing values

• Loop through the array and check if each element is greater than the previous one

• Once you find the maximum element, check if the remaining elements are in decreasing order

• If yes, return true else false

Design a cricinfo (LLD)

• Identify the entities: players, teams, matches, scorecards, tournaments, etc.

• Define the relationships between entities

• Create a database schema to store the data

• Implement APIs to fetch and update data

• Design a UI to display the information

• Consider scalability and performance

• Ensure data security and privacy

Frameworks provide structure and pre-built components for software development, but can also limit flexibility and require learning curve.

• Advantage: Provides structure and pre-built components for faster development

• Advantage: Can improve code quality and maintainability

• Disadvantage: Can limit flexibility and customization

• Disadvantage: Requires learning curve and potential dependency issues

• Example: ReactJS provides a fr...read more

Oops stands for Object-Oriented Programming. It is a programming paradigm that uses objects to represent real-world entities.

• Advantages: code reusability, modularity, encapsulation, inheritance, polymorphism

• Disadvantages: complexity, steep learning curve, performance overhead

• Example: creating a class 'Car' with properties like 'make', 'model', and 'year', and methods like 'start_engine' and 'stop_engine'

Use dynamic programming to find the longest palindromic substring in a given string.

• Iterate through the string and expand around each character to find palindromes.

• Store the length of the longest palindrome found so far.

• Return the substring based on the start and end indices of the longest palindrome.

To serialize and deserialize a tree, use a recursive approach to traverse the tree and store the data in a suitable format.

• Use pre-order traversal to serialize the tree by storing the node values in a list or string.

• For deserialization, reconstruct the tree by recursively building nodes from the serialized data.

• Consider using JSON or XML format for serialization to easily store and retrieve tree structure.

Use regex library to match given regex with string.

• Use a regex library like re in Python to match the given regex with the string.

• Check if the regex matches the string using the library functions.

• Handle cases where the regex contains special characters like . and * appropriately.

Throttling is a technique used to control the rate of requests sent to a server.

• Throttling helps prevent server overload by limiting the number of requests processed at a time.

• Implementing a throttle function involves setting a maximum request rate and delaying excess requests.

• Example: Implementing a throttle function in a web application to limit the number of API calls made to a third-party service.

• Example: Throttlin...read more

Sort the squares of elements in a sorted array and return the sorted response.

• Iterate through the array and square each element.

• Store the squared values in a new array.

• Sort the new array and return it.

A promise is a commitment to do something in the future, typically used for asynchronous operations in JavaScript.

• Promises are used to handle asynchronous operations in JavaScript.

• They represent a value that may be available now, in the future, or never.

• Promises have three states: pending, fulfilled, or rejected.

• Example: new Promise((resolve, reject) => { setTimeout(() => resolve('Done!'), 1000); });

Event loop is a mechanism that allows for asynchronous execution of code by managing the order of events in a single thread.

• Event loop continuously checks the call stack for any functions that need to be executed, and processes them in a non-blocking manner.

• Different types of queues in event loop include microtask queue (Promise callbacks), macrotask queue (setTimeout, setInterval callbacks), and animation frame queue

Virtual DOM is a lightweight copy of the actual DOM, used to improve performance by minimizing direct manipulation of the real DOM.

• Virtual DOM is a concept used in frameworks like React to optimize rendering performance.

• Changes are first made to the virtual DOM, which is then compared to the real DOM to identify the minimal updates needed.

• This approach reduces the number of actual DOM manipulations, resulting in faster...read more