60+ TRATICO Engineering Interview Questions and Answers

Session is maintained using session affinity or sticky sessions.

• Session affinity ensures that a user's session is always directed to the same server.

• Load balancer uses a unique identifier to route requests to the same server.

• Sticky sessions can be implemented using cookies or URL rewriting.

• Session replication can also be used to maintain session data across multiple servers.

Session is maintained through session affinity or sticky sessions.

• Session affinity ensures that a user's session is always directed to the same server.

• Sticky sessions use cookies to track the user's session and direct them to the same server.

• Load balancers can also use IP-based affinity to maintain sessions.

• Session persistence can be configured based on time or number of requests.

• Without session affinity, users may experience issues with lost data or inconsistent behavior.

Find the first non-repeating character in a string.

• Create a hash table to store the frequency of each character in the string.

• Iterate through the string and check the frequency of each character.

• Return the first character with a frequency of 1.

To connect to MySQL database using PHP, create a Connection class.

• Use mysqli_connect() function to establish a connection

• Pass the database credentials as parameters to the function

• Create a constructor method to initialize the connection

• Create a query method to execute SQL queries

• Close the connection using mysqli_close() method

To increase PHP memory at run time, modify the php.ini file or use ini_set() function.

• Edit the memory_limit value in php.ini file

• Use ini_set('memory_limit', '256M') function to increase memory limit at run time

• Check for memory leaks in the code

• Use unset() function to free up memory after use

Explaining abstract class, interface and multiple inheritance in PHP.

• Abstract class is a class that cannot be instantiated and can have abstract methods.

• Interface is a collection of abstract methods and constants that can be implemented by a class.

• Multiple inheritance is not possible in PHP, but can be achieved using interfaces.

• Interfaces can be implemented by multiple classes, allowing for multiple inheritance-like behavior.

Find pair of elements in an array whose sum is equal to a given number K.

• Iterate through the array and for each element, check if K minus the element exists in the array.

• Use a hash table to store the elements and their indices for faster lookup.

• If multiple pairs exist, return any one of them.

• If no pair exists, return null or an appropriate message.

Find missing element in an array of elements from 0 to n-1

• Calculate sum of all elements in array and subtract from sum of n natural numbers

• Use XOR operation on all elements and n natural numbers

• Sort the array and find the missing element

WAP to check if linked list elements is a palindrome without using any extra space.

• Traverse the linked list and reverse the second half of the list

• Compare the first half with the reversed second half

• Use two pointers to traverse the list, one at normal speed and other at double speed

WAP to find smallest palindrome number larger than given number.

• Convert the given number to string and check if it is already a palindrome.

• If not, increment the number and check if it is a palindrome.

• Repeat until a palindrome number larger than the given number is found.

• Use a while loop to implement the above steps.

Write a stored procedure from given tables and conditions

• Identify the tables and their relationships

• Determine the conditions to be used in the stored procedure

• Write the SQL code for the stored procedure

• Test the stored procedure to ensure it returns the desired results

To burn a wood of some size in 15 min instead of 30 min, split it into two halves and burn them simultaneously.

• Split the wood into two halves

• Burn both halves simultaneously

• Use a larger flame or accelerant to increase the burning rate

There are three types of errors in PHP: syntax errors, runtime errors, and logical errors.

• Syntax errors occur when the code is not written correctly, such as missing semicolons or parentheses.

• Runtime errors occur during the execution of the code, such as trying to access an undefined variable.

• Logical errors occur when the code runs without errors, but produces unexpected results, such as a miscalculation in a formula.

Singleton pattern ensures only one instance of a class is created and provides a global point of access to it.

• Create a private constructor to prevent direct instantiation of the class

• Create a private static instance of the class

• Create a public static method to access the instance

• Ensure thread safety by using synchronized keyword or static initialization block

• Examples: Logger, Configuration Manager, Database Connection Manager

To implement critical section in Java, use synchronized keyword on the shared variable.

• Use synchronized keyword to ensure only one thread can access the shared variable at a time.

• The shared variable should be the object on which the synchronized keyword is applied.

• Example: synchronized(sharedObject) { //critical section code }

php.ini is a configuration file for PHP that allows users to customize various settings.

• Change PHP settings such as memory limit, file upload size, and error reporting

• Enable or disable extensions and modules

• Set timezone and language settings

• Configure email settings

• Control caching and session settings

The issue could be due to various factors such as targeting, messaging, or timing. Steps taken include analyzing data, conducting A/B testing, and adjusting strategies accordingly.

• Identify the specific goals and KPIs of the campaign to determine where it may be falling short

• Analyze data such as click-through rates, conversion rates, and engagement metrics to pinpoint areas of underperformance

• Conduct A/B testing to test different variables such as ad copy, visuals, or targetin...read more

Find missing element in an array of elements from 0 to n-1 using different approaches.

• Approach 1: Sum of n natural numbers - sum of array elements

• Approach 2: XOR all array elements and XOR with n natural numbers

• Approach 3: Binary search for missing element

• Approach 4: Using a hash table to store array elements

Use window.location to get domain from a url in jQuery.

• Use window.location to get the full url

• Use .hostname to get the domain name

• Use .replace() to remove 'www.' if present

Targeting specific audience involves identifying key demographics, interests, and behaviors to tailor marketing strategies.

• Conduct market research to understand the target audience's demographics, interests, and behaviors.

• Utilize data analytics tools to track and analyze customer behavior and preferences.

• Create buyer personas to represent different segments of the target audience.

• Use social media targeting options to reach specific demographics based on age, location, interes...read more

A/B testing is a method used to compare two versions of a webpage or app to determine which one performs better.

• A/B testing involves creating two versions (A and B) of a webpage or app with one differing element, such as a headline or call-to-action button.

• Users are randomly shown either version A or B, and their interactions are measured to determine which version performs better in terms of conversions or other metrics.

• The version that performs better is then implemented as...read more

Connection pooling is a technique of reusing database connections to improve performance.

• Connection pooling helps to reduce the overhead of creating and destroying database connections.

• It maintains a pool of connections that can be reused by multiple clients.

• Connection pooling is commonly used in web applications to handle multiple requests simultaneously.

• It can be configured with parameters like maximum number of connections, timeout, etc.

• Examples of connection pooling libra...read more

To convert from video to audio, you can use various software and online tools.

• Use software like VLC Media Player, Handbrake, or FFmpeg to convert video to audio.

• Online tools like Online-Convert.com and CloudConvert.com can also be used for conversion.

• Choose the desired audio format and quality before converting.

• Ensure that the video file is compatible with the software or tool being used for conversion.

A singleton class in PHP is a class that can only be instantiated once.

• Create a private constructor to prevent direct instantiation

• Create a private static variable to hold the instance of the class

• Create a public static method to get the instance of the class

• Ensure that the public static method always returns the same instance

Session in PHP allows to store user data on the server for later use.

• Session starts when a user logs in and ends when the user logs out or the session expires.

• Session data is stored on the server and identified by a unique session ID.

• Session variables can be set and accessed using the $_SESSION superglobal array.

• Session can be destroyed using the session_destroy() function.

• Session can be used to store user-specific data such as login credentials, shopping cart items, etc.

The image file height refers to the vertical size of the image in pixels.

• Image file height is measured in pixels.

• It determines the vertical size of the image.

• The height can be found in the image file's metadata or by opening the image in an image editor and checking its properties.

I have extensive experience with Google Tag Manager, including setting up tracking codes, triggers, and variables.

• Implemented various tracking codes for website analytics and conversion tracking

• Created custom triggers and variables to track specific user interactions

• Utilized Google Tag Manager to streamline the process of adding and updating tags on websites

The question is unclear and does not make sense in the context of a Wordpress Developer interview.

• The question is likely a mistake or a joke.

• There is no codec with the last name.

• Codec is a term used in digital media to refer to a method of encoding and decoding data.

• As a Wordpress Developer, knowledge of codecs may be useful for working with multimedia content on websites.

OGG to MP3 conversion can be done using various online converters or software.

• Use online converters like CloudConvert, Convertio, etc.

• Use software like VLC media player, Audacity, etc.

• Install FFmpeg and use command line to convert.

• Check for copyright issues before converting.

• Ensure quality of converted file is satisfactory.

The integration workflow involves connecting different applications to enable seamless data exchange.

• Identify the systems that need to be integrated

• Define the data flow between the systems

• Develop APIs or connectors for data exchange

• Test the integration to ensure data accuracy and consistency

• Monitor and maintain the integration for ongoing performance

• Examples: Integrating CRM system with marketing automation platform, connecting e-commerce website with inventory management sys...read more

Use a media converter software or an online converter tool to convert WAV to MP3.

• Download and install a media converter software like Audacity or Freemake Audio Converter.

• Open the software and import the WAV file.

• Choose MP3 as the output format and select the desired quality.

• Click on the convert button and wait for the process to complete.

• Alternatively, use an online converter tool like Online-Convert or Zamzar.

• Upload the WAV file and select MP3 as the output format.

• Click on ...read more

Amitabh Chaudhry is the CEO of Axis Bank.

• Amitabh Chaudhry became the CEO of Axis Bank in January 2019.

• He was previously the MD and CEO of HDFC Life Insurance Company.

• Under his leadership, Axis Bank has focused on digital transformation and customer-centric initiatives.

A cropped image is an image that has been trimmed or cut to a specific size or shape.

• Cropping an image removes unwanted parts of the image

• Cropped images are often used for thumbnails or profile pictures

• Cropping can be done manually or with software like Photoshop

• Aspect ratio should be considered when cropping to avoid distortion

GST stands for Goods and Services Tax.

• GST stands for Goods and Services Tax

• It is an indirect tax levied on the supply of goods and services in India

• Implemented on 1st July 2017 to replace multiple indirect taxes like VAT, service tax, etc.

Java code to generate fibonacci series

• Use a loop to generate the series

• Start with the first two numbers 0 and 1

• Add the previous two numbers to get the next number

Three approaches to center a div element

• Using CSS flexbox: set display property of parent element to flex and justify-content to center

• Using CSS grid: set display property of parent element to grid and place the div in the center grid area

• Using margin: set margin property of the div to auto