30+ Zscaler Softech Interview Questions and Answers

Count the total number of subsequences in which all elements are equal in an integer array.

• Iterate through the array and count the frequency of each element.

• Calculate the total number of subsequences for each element using the formula (frequency * (frequency + 1) / 2).

• Sum up the total number of subsequences for all elements to get the final result.

Reverse a string using a stack

• Create a stack to store characters of the input string

• Pop characters from the stack to reverse the string

• Reconstruct the reversed string from the popped characters

To create a singleton ensuring reflection does not mess up the implementation, use an enum or a private constructor with a static field.

• Use an enum to create a singleton as enums are inherently singletons and cannot be instantiated multiple times.

• Alternatively, use a private constructor with a static field to create a singleton.

• To prevent reflection from creating multiple instances, throw an exception in the constructor if an instance already exists.

Swap characters from uppercase to lowercase and lowercase to uppercase in a given string.

• Iterate through each character in the string

• Check if the character is uppercase or lowercase

• Swap the case of the character using bitwise XOR operation

• Build the resulting string with the swapped characters

Use load balancing, caching, and scaling techniques to handle millions of requests from clients.

• Implement load balancing to distribute requests evenly across servers.

• Utilize caching mechanisms to store frequently accessed data and reduce load on servers.

• Scale horizontally by adding more servers to handle increased traffic.

• Optimize code and database queries to improve performance and reduce response times.

ConcurrentHashMap allows multiple threads to access and modify the map concurrently, while SynchronizedHashMap ensures thread-safety by allowing only one thread to access the map at a time.

• ConcurrentHashMap is more efficient in scenarios with high concurrency as it allows concurrent read and write operations.

• SynchronizedHashMap is simpler to use and provides thread-safety, but can lead to performance degradation in highly concurrent environments.

• ConcurrentHashMap achieves thr...read more

Semaphores in Java are used for controlling access to a shared resource. They can be implemented using the java.util.concurrent package.

• Use the Semaphore class from the java.util.concurrent package

• Create a Semaphore object with an initial number of permits

• Use the acquire() method to acquire a permit before accessing the shared resource

• Use the release() method to release a permit after accessing the shared resource

Bitmask in Postgresql is used to store and manipulate multiple boolean values within a single integer column.

• Bitmask is a technique to represent a set of boolean flags using binary digits.

• In Postgresql, the bitwise operators (&, |, ^, ~) can be used to perform operations on bitmasks.

• To set a specific flag in a bitmask, use the bitwise OR operator (|).

• To check if a flag is set in a bitmask, use the bitwise AND operator (&).

• To toggle a flag in a bitmask, use the bitwise XOR ope...read more

The best time to buy and sell stock is when the price is low to buy and high to sell, maximizing profit.

• Buy when the stock price is low and sell when it is high

• Consider market trends and analysis to predict the best time to buy and sell

• Avoid emotional decision-making and stick to a well-thought-out strategy

Yes, I can create an application without the help of Google.

• I have a strong understanding of Java programming language and its libraries

• I have experience in developing applications without relying on external resources

• I have a good grasp of software development principles and best practices

Experience with Terraform for creating EKS clusters

• Utilize Terraform modules to define EKS cluster resources

• Leverage Terraform provider for AWS to interact with EKS API

• Use Terraform state management for tracking cluster changes

Implement a circular list

• Use a linked list where the last node points back to the first node

• Keep track of the current node for easy traversal

• Ensure proper handling of edge cases like empty list or single node

The OSI model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven different layers.

• Physical Layer: Deals with physical connections and transmission of raw data. Example: Ethernet cables.

• Data Link Layer: Manages data transfer between devices on the same network. Example: MAC addresses.

• Network Layer: Handles routing and forwarding of data packets. Example: IP addresses.

• Transport Layer: Ensures end-to-end communication ...read more

Streams in Node.js and Python are mechanisms for reading and writing data in chunks, rather than all at once.

• Streams in Node.js allow you to read or write data continuously, without loading the entire file into memory at once.

• In Python, streams are implemented using file objects, which can be read or written to in chunks.

• Streams are useful for processing large amounts of data efficiently, as they allow for asynchronous processing and reduce memory usage.

• Examples: Reading a la...read more

Deadlock in OS is a situation where two or more processes are unable to proceed because each is waiting for the other to release a resource.

• Occurs when processes are stuck in a circular wait for resources

• Can be prevented by using proper resource allocation strategies like avoiding circular waits

• Examples include two processes each holding a resource the other needs

Implementation of ML concepts in projects involves identifying suitable algorithms, collecting and preprocessing data, training models, and evaluating performance.

• Identify the problem to be solved and determine if ML is the appropriate solution

• Collect and preprocess data to ensure it is clean and relevant for training

• Select suitable algorithms based on the problem and data characteristics

• Train the models using the data and fine-tune parameters for optimal performance

• Evaluate ...read more

Constraints in SQL are rules that are enforced on data in a table to maintain data integrity.

• Primary Key: Ensures each row in a table is unique

• Foreign Key: Ensures referential integrity between two tables

• Unique: Ensures each value in a column is unique

• Check: Ensures values meet a specific condition

• Not Null: Ensures a column cannot have NULL values

The release process in my current organization involves automated testing, continuous integration, and deployment pipelines.

• We use version control systems like Git to manage code changes.

• Automated testing is done using tools like Jenkins and Selenium.

• Continuous integration is achieved through pipelines in tools like Jenkins or GitLab.

• Deployment pipelines are set up to automatically deploy code to different environments like development, staging, and production.

• We follow a rel...read more

Creating a bar graph using array of strings

• Create an array of strings representing the data points for the bar graph

• Each string should indicate the value of the bar and its corresponding label

• Use a visualization tool or library to plot the bar graph based on the array of strings

Zscaler is a cloud-based security platform that provides internet security and web filtering solutions.

• Zscaler offers a range of features such as cloud sandboxing, SSL inspection, and data loss prevention.

• Its competitors include Cisco Umbrella, Symantec Web Security, and McAfee Web Gateway.

• Zscaler's cloud-based approach allows for easy scalability and flexibility compared to on-premise solutions.

• Zscaler also offers a comprehensive dashboard for monitoring and managing securit...read more

I have extensive experience working with Kubernetes in various environments.

• Managed Kubernetes clusters using tools like kubectl and Helm

• Implemented CI/CD pipelines for deploying applications on Kubernetes

• Optimized resource utilization and scalability of applications on Kubernetes

• Troubleshooted and resolved issues related to Kubernetes clusters

• Worked with Kubernetes networking and storage solutions like Ingress and Persistent Volumes

Understanding of Linux networking at a deep level

• Knowledge of TCP/IP stack and protocols

• Experience with network configuration and troubleshooting

• Familiarity with tools like iptables, tcpdump, and netstat

• Understanding of routing and subnetting

• Ability to optimize network performance and security

Search for an element in a rotated sorted array

• Use binary search to find the pivot point where the array is rotated

• Divide the array into two subarrays and perform binary search on the appropriate subarray

• Handle cases where the target element is on the left or right side of the pivot

HashMap is a data structure that stores key-value pairs and uses hashing to quickly retrieve values based on keys.

• HashMap internally uses an array of linked lists to store key-value pairs.

• When a key-value pair is added, the key is hashed to determine the index in the array where it will be stored.

• If multiple keys hash to the same index, a collision occurs and the key-value pairs are stored in a linked list at that index.

• To retrieve a value, the key is hashed again to find the...read more

DHCP is a network protocol that automatically assigns IP addresses to devices on a network.

• DHCP stands for Dynamic Host Configuration Protocol.

• It allows devices to obtain IP addresses and other network configuration information from a DHCP server.

• DHCP operates on the client-server model, where the client requests an IP address and the server assigns one.

• DHCP uses a lease mechanism to control the amount of time a device can use an IP address before it must be renewed.

• DHCP redu...read more

Data integration & pipeline involves combining data from multiple sources and processing it to make it usable for analysis.

• Data integration is the process of combining data from different sources into a single, unified view.

• Data pipeline refers to the series of steps that data goes through from collection to analysis.

• Data integration ensures that data is clean, consistent, and accurate before being processed in the pipeline.

• Examples of data integration tools include Talend, I...read more

Experience with Jenkins and Terraform for automation and infrastructure management.

• Used Jenkins for continuous integration and continuous deployment pipelines

• Utilized Terraform for infrastructure as code to provision and manage resources

• Integrated Jenkins with Terraform for automated infrastructure deployment

• Troubleshooted and optimized Jenkins and Terraform configurations

CDN stands for Content Delivery Network, used to deliver web content efficiently by caching it on servers located closer to users.

• CDNs help improve website performance by reducing latency and increasing loading speeds.

• They distribute content across multiple servers globally to ensure faster delivery to users.

• CDNs also help reduce server load and bandwidth usage by serving cached content instead of fetching it from the origin server every time.

• Popular CDN providers include Clo...read more

A modern and user-friendly login page with email and password fields

• Include a clean and simple design with a logo and branding

• Add input fields for email and password with proper validation

• Include a 'Forgot Password' link for password recovery

• Add a 'Remember Me' checkbox for convenience

• Include a 'Sign In' button for submitting the form