1000+ Technical Lead Interview Questions and Answers

Data sync replicates data across multiple databases while multi AZ provides high availability within a single region.

• Data sync is used for scaling read-heavy workloads and disaster recovery.

• Multi AZ is used for high availability and automatic failover within a single region.

• Data sync can be used across regions while multi AZ cannot.

• Data sync can be used with different database engines while multi AZ is specific to certain engines like RDS.

• Both can be used together for maximum...read more

Constructor injection is preferred over Setter injection.

• Constructor injection ensures that all required dependencies are provided at the time of object creation.

• Setter injection allows for optional dependencies and can be used for dynamic changes.

• Constructor injection is more secure as the object is fully initialized before use.

• Setter injection can lead to inconsistent object states if not used carefully.

• Constructor injection is easier to test and maintain.

• Setter injection c...read more

Implement a systematic onboarding process to ensure employees have access to necessary applications efficiently.

• Conduct a needs assessment: Identify the specific applications required for each role.

• Utilize an access management system: Implement tools like Okta or Azure AD for streamlined access control.

• Create a checklist: Develop a standardized checklist for onboarding that includes all necessary applications.

• Regular audits: Schedule periodic reviews of access permissions to ...read more

Control statements in database are used to control the flow of execution of SQL statements.

• Control statements in database include IF, CASE, WHILE, LOOP, and GOTO.

• They are used to control the flow of execution of SQL statements.

• They help in making decisions, looping through data, and jumping to specific parts of code.

• For example, the IF statement can be used to check a condition and execute a block of code if the condition is true.

• The CASE statement can be used to perform diff...read more

Java 8 features include lambda expressions, functional interfaces, streams, and default methods.

• Lambda expressions allow you to write code in a more concise and readable way.

• Functional interfaces enable the use of lambda expressions.

• Streams provide a way to work with collections of objects in a functional style.

• Default methods allow interfaces to have method implementations.

• Examples: Using lambda expressions to iterate over a list, using streams to filter and map data.

Implemented the Observer design pattern.

• Used to maintain consistency between related objects

• Allows for one-to-many relationships between objects

• Used in event-driven systems

• Example: Used to update UI when data changes in backend

List and Tuple differences, ordering, indexing, and iteration

• List is mutable, Tuple is immutable

• Lists are ordered and indexed starting from 0, Tuples are also ordered but indexed starting from 0

• Iterating through a List: for item in my_list: print(item)

• Iterating through a Tuple: for item in my_tuple: print(item)

Integrating monitoring services and deciding third party services based on weightage

• Identify key performance indicators (KPIs) for monitoring

• Evaluate potential third party services based on KPIs and other factors such as cost and reliability

• Assign weightage to each factor based on its importance

• Use a scoring system to rank and compare different third party services

• Continuously monitor and reassess the performance of third party services

IOC Container is a core feature of Spring Framework that manages the dependencies between objects.

• IOC stands for Inversion of Control

• It is used to achieve loose coupling between objects

• It allows objects to be created and wired together by an external framework

• It reduces the amount of code needed for configuration and maintenance

• Examples of IOC Containers in Spring are ApplicationContext and BeanFactory

Microservices are a software architecture pattern where applications are built as a collection of small, loosely coupled services.

• Microservices allow for modular development and deployment of applications.

• Each microservice can be developed, deployed, and scaled independently.

• Microservices communicate with each other through APIs.

• They promote flexibility, scalability, and fault tolerance.

• Examples of microservices include Netflix, Amazon, and Uber.

UL 94 is a flammability standard for plastic materials. SS304 and SS316 are different grades of stainless steel. Various materials are used in vacuum chambers.

• UL 94 is a standard used to measure the flammability of plastic materials.

• SS304 and SS316 are both grades of stainless steel, but SS316 has higher corrosion resistance and strength.

• Materials used in vacuum chambers include stainless steel, aluminum, and glass.

• The choice of material for a vacuum chamber depends on factor...read more

Yes, I have configured saga design pattern in my project.

• I have used saga design pattern to manage complex workflows and transactions.

• I have implemented sagas using libraries like Redux-Saga and NServiceBus.

• I have used sagas to handle scenarios like order processing, payment processing, and inventory management.

• I have also used sagas to handle compensating transactions in case of failures.

Redux is a predictable state container for JavaScript apps.

• Redux is a library for managing application state

• It provides a predictable state container by enforcing a strict unidirectional data flow

• Redux can be used with any UI library or framework

• It is commonly used with React to manage state in complex applications

• Redux allows for easy debugging and testing of state changes

• Actions are dispatched to update the state, and reducers handle the updates

• Selectors can be used to retr...read more

PDO (PHP Data Objects) is a database access layer providing a consistent interface for accessing databases in PHP.

• Prevents SQL injection attacks by using prepared statements

• Supports multiple database drivers like MySQL, PostgreSQL, SQLite, etc.

• Provides error handling through exceptions

• Allows for parameterized queries for improved performance

• Promotes code reusability and maintainability

Various aspects of big data in my work include data collection, storage, processing, analysis, and visualization.

• Data collection from various sources such as sensors, social media, and IoT devices

• Storage in distributed systems like Hadoop or cloud storage solutions

• Processing using technologies like MapReduce, Spark, or Flink

• Analysis to extract insights and patterns from large datasets

• Visualization to present the findings in a meaningful way

BSOD stands for Blue Screen of Death, indicating a system error. No power means the device is not receiving power, while no post means the device is not passing the Power-On Self Test.

• BSOD is a blue screen error displayed by Windows operating systems when a critical system error occurs.

• No power indicates that the device is not receiving any power supply.

• No post refers to the device not passing the Power-On Self Test during boot up.

• BSOD can be caused by hardware or software is...read more

Finding an integer not present in a given array.

• Iterate through the array and mark the presence of each integer in a hash table.

• Then iterate through the hash table to find the missing integer.

• Alternatively, sort the array and iterate through to find the first missing integer.

To create a CMDB table, define the attributes and their relationships. Attributes can be added to the CMDB based on their relevance.

• Identify the entities to be included in the CMDB

• Define the attributes for each entity

• Determine the relationships between the entities

• Create the table structure based on the defined attributes and relationships

• Add attributes to the CMDB based on their relevance and importance

Dependency Injection is a design pattern used in Magento 2 to inject dependencies into a class.

• Dependency Injection is a way to achieve loose coupling between classes.

• It allows for easier testing and maintenance of code.

• In Magento 2, dependencies are injected through constructor or setter methods.

• Example: injecting a logger object into a class that needs to log messages.

Coroutines are lightweight threads in Kotlin that allow for asynchronous programming without the overhead of traditional multithreading.

• Coroutines are cooperative, meaning they can pause and resume execution at specific points in the code.

• They are more efficient than multithreading because they don't require creating new threads for each task.

• Coroutines can be used for both CPU-bound and IO-bound tasks.

• They simplify error handling and make code more readable.

• Example: Using co...read more

intern() method of String returns a canonical representation of the string object.

• The intern() method returns a string that has the same contents as the original string, but is guaranteed to be from a pool of unique strings.

• This method is useful when comparing strings for equality as it compares the references instead of the contents.

• Example: String s1 = new String("hello"); String s2 = s1.intern(); // s2 will be from the string pool

Code to find repeated characters in string with count using Java 8

• Convert string to char array

• Use streams to group by character and count

• Filter out characters with count less than 2

• Print the repeated characters with their count

A singleton class is a class that can only be instantiated once. It is important to secure it in a multi-threading environment.

• Create a private constructor to prevent external instantiation

• Create a private static instance of the class

• Create a public static method to return the instance

• Use synchronized keyword to ensure thread safety

• Consider using double-checked locking to improve performance

Practices for designing a good database include normalization, indexing, proper data types, relationships, and performance optimization.

• Normalize data to reduce redundancy and improve data integrity

• Use indexing to speed up data retrieval

• Choose appropriate data types to optimize storage and querying

• Establish relationships between tables for data consistency

• Optimize database performance through query optimization and proper indexing

Sorry, there is no such thing as Foxconn ful form FHH.

Technical Lead interview questions on mutex, thread communication, CompletableFuture, and deadlock

• Mutex is a synchronization mechanism to prevent multiple threads from accessing shared resources simultaneously

• Thread communication can be achieved through shared memory, message passing, or synchronization primitives like semaphores

• CompletableFuture is a Java class that represents a future result of an asynchronous computation and provides methods to chain and combine them

• Deadlo...read more

Defect leakage is a serious issue. I would take immediate action to identify the root cause and implement corrective measures.

• Analyze the defect leakage data to identify the root cause

• Implement corrective measures to fix the issue

• Conduct a thorough review of the testing process to prevent future leakage

• Communicate the issue and resolution to stakeholders

• Track and monitor the effectiveness of the corrective measures

Co-ordination with Roaming Operators, IPX, GRX and SCCP Providers involves managing relationships and ensuring smooth communication.

• Establishing and maintaining relationships with roaming operators, IPX, GRX and SCCP providers

• Negotiating contracts and service level agreements

• Monitoring service performance and resolving issues

• Collaborating with internal teams to ensure seamless communication

• Staying up-to-date with industry trends and regulations

In COBOL, parm parameters can be accepted using the ACCEPT statement. The declaration structure includes the PICTURE clause.

• Use ACCEPT statement to accept parm parameter in COBOL

• Declare parm parameter using PICTURE clause in COBOL

• Example: ACCEPT parm-parameter

• Example: 01 parm-parameter PIC X(10)

We use @Value in Spring Boot to inject values from properties files or environment variables.

• Allows for external configuration of application properties

• Values can be injected from properties files or environment variables

• Can be used to inject values into fields, constructors, or methods

• Example: @Value("${my.property}") private String myProperty;

Use two threads to print numbers 1-10 in correct order

• Create two threads, one for printing odd numbers and one for printing even numbers

• Use synchronization mechanisms like mutex or semaphore to ensure correct order

• Example: Thread 1 prints 1, 3, 5, 7, 9 and Thread 2 prints 2, 4, 6, 8, 10

Interface is a contract that defines the methods a class must implement, while abstract class can have both abstract and concrete methods.

• Interface cannot have any implementation, while abstract class can have both abstract and concrete methods.

• A class can implement multiple interfaces but can only inherit from one abstract class.

• Interfaces are used to achieve multiple inheritance in Java, while abstract classes are used to provide a common base for subclasses.

• Interfaces are ...read more

Implementing DIP in .NET Core

• Create an interface for the dependency

• Implement the interface in a separate class

• Inject the dependency into the consuming class

• Use dependency injection container to resolve dependencies

The ViewModel survives configuration changes by being retained by the system.

• ViewModels are designed to survive configuration changes like screen rotations or language changes.

• When an activity is destroyed and recreated, the ViewModel is not destroyed and retains its data.

• The ViewModel is associated with the activity's lifecycle and is retained until the activity is finished.

• The retained ViewModel instance can be accessed by the newly created activity to restore its state.

Orchestration and choreography are design patterns used in distributed systems.

• Orchestration involves a central controller that coordinates the interactions between services.

• Choreography involves services communicating with each other directly without a central controller.

• Orchestration is more suitable for complex workflows while choreography is more flexible.

• Examples of orchestration tools include Kubernetes and Apache Airflow.

• Examples of choreography tools include Apache Ka...read more

SQL performance tuning for stored procedures

• Identify the bottleneck in the stored procedure

• Check for missing indexes and optimize them

• Use parameterized queries to avoid SQL injection attacks

• Avoid using SELECT * and only select necessary columns

• Use temporary tables or table variables for complex queries

• Avoid using cursors and use set-based operations instead

• Monitor server resources like CPU, memory, and disk usage

• Consider using query hints like NOLOCK or MAXDOP

• Regularly update...read more

We use MySQL and MongoDB for our project.

• MySQL is used for structured data storage and querying.

• MongoDB is used for unstructured data storage and retrieval.

• We also use Redis for caching purposes.

• Our project involves handling large amounts of data, hence the need for multiple databases.

Techniques to finetune an LLM and evaluate it

• Fine-tuning techniques include adjusting learning rate, batch size, and training data size

• Evaluate LLM by measuring performance metrics like perplexity, accuracy, and F1 score

• Use validation data to assess generalization ability of the model

• Regularly monitor and update the model based on new data and feedback

• Consider using transfer learning to improve LLM performance

A customer is an individual or organization that purchases goods or services, while a client is a person or entity that receives professional services or advice.

• Customers typically make one-time purchases, while clients often have ongoing relationships with service providers.

• Customers may not have a direct relationship with the seller, while clients usually have a more personal connection with their service provider.

• Customers are focused on the products or services they are b...read more

Design patterns are reusable solutions to common problems in software design. Examples include Singleton, Factory, and Observer.

• Design patterns are solutions to common problems in software design

• They help in creating reusable and maintainable code

• Examples include Singleton, Factory, Observer, and Strategy patterns

Get third highest salary in given employee list using Java 8

• Sort the employee list in descending order of salary using Comparator

• Use distinct() to remove duplicates

• Skip the first two highest salaries using skip()

• Use findFirst() to get the third highest salary

UNIX shell scripting is a command-line interface used to automate tasks. PLSQL packages/procedures are used to store and execute SQL code.

• UNIX shell scripting is used to automate repetitive tasks and can be used to create complex scripts.

• PLSQL packages/procedures are used to store and execute SQL code, making it easier to manage and reuse code.

• Shell scripts can be used to automate tasks such as backups, file management, and system monitoring.

• PLSQL packages/procedures can be u...read more

DataParameter is a TestNG annotation used to pass data to test methods.

• DataParameter is used to pass data to test methods in TestNG

• It is used in conjunction with DataProvider to provide test data

• DataParameter can be used to pass multiple parameters to a test method

• Example: @Test(dataProvider = "dp", dataProviderClass = TestData.class)

• Example: public void testMethod(@DataParameter("username") String username, @DataParameter("password") String password)

The stages of Close of Business (COB) include preparation, reconciliation, reporting, and archiving.

• Preparation involves finalizing transactions and ensuring all data is accurate.

• Reconciliation is the process of comparing financial records to ensure they match.

• Reporting involves generating reports for management and stakeholders.

• Archiving is the final stage where all documents and records are stored for future reference.

A variable's value in an embedded device is typically set through initialization in the code or through external input.

• Variables can be initialized with a specific value in the code during declaration.

• Values can also be set dynamically during runtime through user input or sensor data.

• Some variables may have default values set by the firmware or hardware.

• Values can be updated through communication protocols like UART, SPI, or I2C.

• Variables can be modified through interrupts or...read more

Code first approach involves creating the database schema based on the code, while database first approach involves creating the code based on an existing database schema.

• Code first approach focuses on defining the entities and their relationships in code, and then generating the database schema from the code.

• Database first approach involves designing the database schema first, and then generating the code based on the schema.

• Code first approach provides more control over the...read more

Configuring DNS sinkhole for malicious domains on Palo Alto

• Create a security policy to block traffic to malicious domains

• Configure DNS sinkhole profile with the list of malicious domains

• Enable DNS sinkhole in the security policy

• Monitor the logs for any blocked traffic

• Update the list of malicious domains regularly