400+ Lead Engineer Interview Questions and Answers

I have experience troubleshooting AOI machines and have faced difficult situations before.

• I have a strong understanding of AOI technology and its components

• I have experience using diagnostic tools to identify issues

• One difficult situation I faced was when the AOI machine was not detecting defects properly. After thorough analysis, I discovered that the lighting system was faulty and needed to be replaced.

Solid principles are used in application development to create maintainable, scalable, and flexible software.

• Solid principles help in achieving modular and loosely coupled code.

• Single Responsibility Principle (SRP) ensures that a class has only one reason to change.

• Open-Closed Principle (OCP) allows for extension without modification.

• Liskov Substitution Principle (LSP) ensures that derived classes can be substituted for their base classes.

• Interface Segregation Principle (ISP)...read more

Create a Spring Boot controller and required classes for a scenario

• Create a controller class with @RestController annotation

• Define request mapping for different endpoints using @RequestMapping or @GetMapping/@PostMapping annotations

• Implement methods to handle different HTTP requests and return appropriate responses

• Use @Autowired annotation to inject dependencies like services or repositories

• Create service classes to handle business logic and interact with data repositories

• Def...read more

My understanding of 5G technology in my domain is extensive and up-to-date.

• I have a deep understanding of the technical specifications and capabilities of 5G networks.

• I am familiar with the latest developments in 5G technology and how they can be applied to my domain.

• I have experience working with 5G networks and implementing solutions that leverage their capabilities.

• I understand the potential benefits and challenges of 5G technology and how they can impact my domain.

• I stay ...read more

Virtual keyword is used for method overriding while new keyword is used for hiding base class member.

• Virtual keyword is used to allow a derived class to override a method in the base class.

• New keyword is used to hide a base class member in the derived class.

• Virtual keyword is used with the base class method while new keyword is used with the derived class method.

• Virtual keyword is used for runtime polymorphism while new keyword is used for compile-time polymorphism.

Weak reference is a reference that does not prevent the referenced object from being garbage collected.

• Weak references are used in programming languages to avoid memory leaks.

• They are typically used in cache implementations to allow objects to be garbage collected when not in use.

• Weak references are created using WeakReference class in Java.

Tube OD selection depends on factors such as fluid flow rate, pressure, and material compatibility.

• Consider fluid flow rate and pressure to determine appropriate tube OD

• Ensure compatibility of tube material with fluid being transported

• Consult industry standards and guidelines for recommended tube OD sizes

• Factor in any space constraints or installation requirements

• Perform testing and analysis to verify tube OD selection

Eventual consistency is a consistency model used in distributed computing systems.

• It allows for data to be inconsistent for a period of time before eventually becoming consistent.

• It is often used in systems where high availability is more important than immediate consistency.

• Examples include Amazon S3, Cassandra, and Riak.

• It requires conflict resolution mechanisms to handle conflicting updates to the same data.

• It can lead to data anomalies and requires careful design and impl...read more

Map, TreeMap and Set are data structures used in Java to store and manipulate collections of objects.

• Map is an interface that maps unique keys to values.

• TreeMap is a class that implements the Map interface and stores its elements in a sorted order.

• Set is an interface that stores unique elements.

• TreeSet is a class that implements the Set interface and stores its elements in a sorted order.

• All three data structures are part of the Java Collections Framework.

Design patterns are reusable solutions to common software problems.

• Design patterns help in creating maintainable and scalable code.

• Some commonly used design patterns are Singleton, Factory, Observer, and Decorator.

• Singleton pattern ensures that only one instance of a class is created.

• Factory pattern provides an interface for creating objects in a superclass, but allows subclasses to alter the type of objects that will be created.

• Observer pattern allows objects to be notified ...read more

This question is likely related to a discrepancy between a library and netlist causing a difference in the size of PMOS transistors.

• Mismatch between the library and netlist can lead to incorrect sizing of transistors

• Ensure consistency between the library files and netlist to avoid discrepancies

• Check for any errors or warnings related to library and netlist mismatch in the design tool logs

• Verify the sizing of PMOS transistors to identify and correct any differences

CAN protocol is a communication protocol used in automotive and industrial applications. RTR stands for Remote Transmission Request.

• CAN protocol is a message-based protocol used for communication between electronic control units in vehicles and industrial machinery.

• It uses a two-wire differential bus to transmit data between nodes on the network.

• RTR is a bit in the CAN message that indicates whether the message is a data frame or a remote frame.

• Remote Transmission Request (RT...read more

Spring Boot has several modules to support different functionalities.

• Spring Boot Core

• Spring Boot Actuator

• Spring Boot Data

• Spring Boot Security

• Spring Boot Test

• Spring Boot Web

• Spring Boot Batch

• Spring Boot Integration

• Spring Boot Cloud

Method hiding is a technique in object-oriented programming where a subclass provides a method with the same name as a method in its superclass.

• Method hiding is also known as static polymorphism or compile-time polymorphism.

• It allows a subclass to provide its own implementation of a method without affecting the superclass's implementation.

• The method in the subclass must have the same name and signature as the method in the superclass.

• Method hiding is achieved by using the 'ne...read more

Explaining a yocto recipe line by line

• Start with the metadata section, which includes the recipe name, version, license, and maintainer

• Next, define the dependencies required for the recipe to build successfully

• Followed by the source URL or file path for the source code

• Then specify any patches that need to be applied

• Configure the build options and settings

• Finally, define the install and package sections to specify how the recipe should be installed and packaged

The path for the bin directory in Linux is typically /bin.

• The bin directory in Linux contains essential binary executables.

• The path for the bin directory is usually /bin.

• Some common commands found in the bin directory include ls, cp, and mv.

The path for sysconfig directory in Linux is /etc/sysconfig.

• The sysconfig directory in Linux is typically located at /etc/sysconfig.

• This directory contains configuration files for various system services and applications.

• Users can modify these configuration files to customize the behavior of their system.

Designing using only a calculator, pen & paper requires creativity and problem-solving skills.

• Start by defining the problem and identifying key requirements.

• Break down the problem into smaller components and sketch out possible solutions.

• Use the calculator for complex calculations and pen & paper for sketches and notes.

• Iterate on the design, refining it based on feedback and constraints.

• Ensure the final design meets all requirements and is feasible to implement.

AOI programming and algorithms are used for inspecting IC parts.

• AOI programming involves creating algorithms to inspect IC parts for defects.

• These algorithms use image processing techniques to analyze the IC parts.

• The algorithms can detect defects such as missing components, incorrect polarity, and soldering issues.

• AOI programming is essential for ensuring the quality of IC parts in manufacturing.

• Examples of AOI programming software include MIRTEC, CyberOptics, and Koh Young.

Procedures and functions are both subroutines, but functions return a value while procedures do not.

• Functions return a value while procedures do not

• Functions can be used in expressions while procedures cannot

• Functions can have parameters passed by value or reference while procedures can only have parameters passed by reference

• Examples of functions include mathematical operations like addition and subtraction, while examples of procedures include printing to the console or upd...read more

Macros in Zabbix are used to dynamically replace values in item keys, trigger expressions, and other places.

• Macros are denoted by curly braces {}

• They can be used to replace static values with dynamic ones

• Examples include {HOST.NAME}, {ITEM.VALUE}, and {TRIGGER.VALUE}

• Macros can also be defined at the host or global level

Delta Lake is an open-source storage layer that brings ACID transactions to Apache Spark and big data workloads.

• Provides ACID transactions for big data workloads

• Ensures data reliability and quality by enabling schema enforcement and data versioning

• Supports batch and streaming data processing

• Improves data quality and reliability by enabling schema enforcement and data versioning

Designing a white-labeled app involves creating a customizable platform that can be rebranded by different clients.

• Create a flexible design structure that allows for easy customization of colors, logos, and branding elements.

• Implement a robust admin panel where clients can easily upload their branding assets and make changes.

• Ensure that the app's functionality remains consistent across different branding variations.

• Consider offering different pricing tiers for clients based o...read more

OOPS stands for Object-Oriented Programming System. It is a programming paradigm that uses objects to represent and manipulate data.

• OOPS is a programming paradigm that focuses on the concept of objects.

• It allows for the creation of reusable and modular code.

• Objects have properties (attributes) and behaviors (methods).

• Encapsulation, inheritance, and polymorphism are key principles of OOPS.

• Example: In a banking system, an object 'Account' can have properties like account number...read more

Partitions in Kafka are assigned based on the number of partitions specified when creating a topic.

• Partitions are assigned to brokers in a round-robin fashion.

• The number of partitions should be a multiple of the number of brokers to ensure even distribution.

• Reassignment of partitions can be done manually using the Kafka Reassign Partitions tool.

Customization tools and details are essential for tailoring engineering solutions to specific needs.

• Customization tools allow for adjusting parameters to meet unique requirements

• Details provide a deeper understanding of the system being engineered

• Examples include CAD software for designing custom parts and simulation tools for optimizing performance

Linklist program or sorting in linklist.

• For linklist program, create a Node class with data and next pointer

• Implement methods to add, delete, and traverse the linklist

• For sorting, use any sorting algorithm like bubble sort or merge sort

• Traverse the linklist and swap the nodes based on sorting criteria

Stored procedures, functions, and packages are database objects used to encapsulate and execute code.

• Stored procedures are precompiled SQL statements that can be executed multiple times.

• Functions return a single value and can be used in SQL statements.

• Packages are a collection of related procedures, functions, and variables.

• Stored procedures and functions can be used to improve performance by reducing network traffic.

• Packages can be used to organize and modularize code.

• Stored...read more

ERMS stands for Equipment Reliability Monitoring System. It is required to monitor and maintain the reliability of equipment.

• ERMS helps in identifying potential equipment failures before they occur

• It helps in scheduling maintenance and repairs to minimize downtime

• ERMS can also provide data for equipment performance analysis and optimization

• Examples of ERMS include vibration monitoring systems, oil analysis systems, and thermal imaging systems

Recursion is a programming technique where a function calls itself to solve a problem.

• Identify the base case and recursive case

• Ensure the recursive case moves towards the base case

• Use a termination condition to avoid infinite recursion

• Examples: factorial, Fibonacci sequence, binary search

Mcstrut and double wishbone are two different types of suspension systems used in vehicles, each with its own advantages and disadvantages.

• Mcstrut suspension is simpler and more cost-effective, but may not offer as much performance as double wishbone.

• Double wishbone suspension provides better handling and stability, but is more complex and expensive to manufacture.

• Mcstrut suspension is commonly used in front-wheel drive vehicles, while double wishbone is often found in high-p...read more

Use SQL query with ROW_NUMBER() function to delete duplicates and keep one.

• Use ROW_NUMBER() function to assign a unique number to each row partitioned by the duplicate column(s)

• Delete rows where the row number is greater than 1

The notification engine in a project is designed to send timely and relevant notifications to users.

• Implement a system to track user preferences and settings for notifications.

• Utilize a queue system to prioritize and schedule notifications.

• Include options for users to customize notification frequency and content.

• Integrate with external services like email or SMS for notifications delivery.

Program to move all zeros in an array to end

• Iterate through the array and keep track of non-zero elements

• Append non-zero elements to a new array

• Append zeros to the end of the new array

Check constraints ensure data integrity by limiting the values that can be inserted into a database table.

• Check constraints are used to enforce business rules or data validation rules.

• They prevent invalid data from being inserted into a table.

• For example, a check constraint can ensure that a date column only contains dates in the future.

• Check constraints can also be used to limit the range of values that can be inserted into a column.

• For example, a check constraint can ensure...read more

Electrical classification areas are designated areas where the presence of flammable gases, vapors, or dusts require special precautions.

• Electrical equipment installed in these areas must be designed and tested to prevent ignition of the hazardous materials.

• There are three main classifications: Class I for flammable gases and vapors, Class II for combustible dusts, and Class III for ignitable fibers and flyings.

• Each classification is further divided into divisions based on th...read more

Use Stream APIs to count number of characters in a string

• Use the chars() method to convert the string to a stream of characters

• Use the count() method to count the number of characters in the stream

MongoDB is a document-oriented database while Cassandra is a column-family database.

• MongoDB is better suited for complex queries and data modeling.

• Cassandra is better for write-heavy workloads and high availability.

• MongoDB has a flexible schema while Cassandra has a fixed schema.

• MongoDB supports ACID transactions while Cassandra supports eventual consistency.

• MongoDB is more popular for web applications while Cassandra is more popular for IoT and real-time analytics.

Program to find all paths in a binary matrix n*n

• Use backtracking algorithm to explore all possible paths

• Start from the top-left corner and explore all possible paths

• Mark visited cells to avoid revisiting them

• Terminate the search when all possible paths have been explored

• Return all the valid paths found

Creating SQL queries for different scenarios

• Use SELECT statement to retrieve data from a table

• Use WHERE clause to filter data based on specific conditions

• Use JOIN clause to combine data from multiple tables

Stress strain diagrams show the relationship between stress and strain in materials like steel and aluminum.

• Stress strain diagrams for steel typically show a linear elastic region followed by a plastic region before failure.

• Aluminum stress strain diagrams may exhibit more ductility compared to steel.

• The ultimate tensile strength and yield strength can be determined from these diagrams for both materials.

Storage classes in C define the scope and lifetime of variables.

• There are four storage classes in C: auto, register, static, and extern.

• Auto storage class is the default storage class for all local variables.

• Register storage class is used to define local variables that should be stored in a register for faster access.

• Static storage class is used to define local variables that retain their value between function calls.

• Extern storage class is used to declare variables that are ...read more

Communication control service manages communication between different components in a system.

• Communication control service coordinates the flow of information between various parts of a system.

• It ensures that messages are sent and received correctly and in a timely manner.

• Examples include message queues, event-driven architectures, and service-oriented architectures.

A voltage divider network is a circuit that divides a voltage into smaller parts.

• Consists of two resistors in series

• Output voltage is a fraction of input voltage

• Used in various applications such as level shifting and biasing

• Formula for output voltage is Vout = Vin * (R2 / (R1 + R2))

To toggle a particular bit, you can use bitwise XOR operation with 1.

• Use bitwise XOR operation with 1 to toggle a particular bit.

• For example, to toggle the 3rd bit of a number 'num', you can do: num ^= (1 << 2).

Materials can be qualified based on their physical, mechanical, chemical, and thermal properties.

• Qualify materials based on physical properties such as density, hardness, and color.

• Consider mechanical properties like strength, elasticity, and toughness.

• Examine chemical properties such as reactivity, corrosion resistance, and stability.

• Evaluate thermal properties including conductivity, expansion coefficient, and melting point.

Filters in analog electronics are circuits that allow certain frequencies to pass through while blocking others.

• Filters are used to shape the frequency response of a circuit.

• They can be classified as low-pass, high-pass, band-pass, or band-stop filters.

• Examples include RC filters, LC filters, and active filters.

• Filters are commonly used in audio equipment, communication systems, and signal processing.