400+ Lead Engineer Interview Questions and Answers

Nexus 9K hardware models used in Leaf and spine architecture.

• Nexus 9372PX and 9372TX used as leaf switches

• Nexus 9504, 9508, and 9516 used as spine switches

• Nexus 93108TC-EX and 93180YC-EX also used as leaf switches

• All models support VXLAN and ACI

• Highly scalable and flexible architecture

Our automation framework is built using Selenium WebDriver and TestNG.

• We use Selenium WebDriver for browser automation

• TestNG is used for test management and reporting

• We also use Apache POI for data-driven testing

• Our framework is designed to be modular and scalable

• We have implemented page object model design pattern

• We use Jenkins for continuous integration and deployment

During emergency shutdown, the execution plan involves immediate identification of the problem and taking necessary steps to mitigate it.

• Identify the cause of the emergency shutdown

• Initiate the emergency shutdown procedure

• Isolate the affected equipment or area

• Notify relevant personnel and authorities

• Implement emergency response plan

• Conduct post-shutdown analysis and investigation

A circuit breaker is an electrical switch that automatically interrupts an electrical circuit when the current exceeds a certain limit.

• Circuit breakers are designed to protect electrical circuits from damage caused by overloading or short circuits.

• They work by detecting an increase in current flow and then tripping to interrupt the circuit.

• Circuit breakers can be reset manually or automatically depending on the type.

• They come in different sizes and ratings depending on the am...read more

I have worked on developing custom components, templates, workflows, and integrating third-party systems in AEM. In Java, I have worked on backend development, RESTful services, and database interactions.

• Developed custom components and templates in AEM

• Implemented workflows for content approval processes

• Integrated third-party systems with AEM

• Backend development in Java

• Created RESTful services

• Worked on database interactions

A thread-safe implementation of the Singleton pattern ensures that only one instance of a class is created in a multi-threaded environment.

• Use double-checked locking to minimize the use of synchronization and improve performance.

• Declare the instance variable as volatile to ensure visibility across threads.

• Use synchronized block to create the instance if it doesn't exist.

• Return the instance variable in the getInstance() method.

Yes, I have knowledge on PLM tools.

• I have experience working with PLM tools such as Teamcenter and Windchill.

• I have used PLM tools to manage product data, collaborate with cross-functional teams, and track project progress.

• I am familiar with PLM concepts such as BOM management, change management, and version control.

• I have also worked on customizing PLM tools to meet specific business requirements.

• Overall, my experience with PLM tools has helped me streamline product developm...read more

PHP is a server-side scripting language used for web development. The current version is PHP 8.0.

• PHP stands for Hypertext Preprocessor

• It is an open-source language

• PHP is used for creating dynamic web pages

• PHP 8.0 was released on November 26, 2020

Printing to console will not happen as System.out is null.

• System.out is a static field in the System class that represents the standard output stream.

• Assigning null to System.out means that any attempt to print to console will result in a NullPointerException.

• To redirect console output to a file or another output stream, System.setOut() method can be used.

Debugging a project in production requires a systematic approach to identify and fix errors efficiently.

• Start by identifying the specific error message or symptom reported by users or monitoring tools.

• Review recent code changes or deployments that may have introduced the error.

• Use logging and monitoring tools to gather more information about the error and its impact.

• Replicate the issue in a controlled environment if possible to understand the root cause.

• Apply fixes carefully ...read more

Business rules are guidelines or constraints defined by a business, while JavaScript is a programming language used for web development.

• Business rules are specific to a business domain and define constraints or guidelines for operations.

• JavaScript is a programming language used for creating interactive web pages and web applications.

• Business rules are typically defined by business analysts or stakeholders, while JavaScript is written by developers.

• Use business rules to enforc...read more

Convert even numbers in a list of strings to odd by adding 1

• Iterate through the list of strings and check if each element is a number

• If the number is even, convert it to odd by adding 1

• Return the modified list of strings

To find out 1m3 concrete costing, calculate the cost of materials and labor involved.

• Determine the cost of cement, sand, aggregate, and water per cubic meter

• Calculate the labor cost involved in mixing, pouring, and finishing the concrete

• Add the material and labor costs to get the total cost of 1m3 concrete

• Consider any additional costs such as transportation, equipment rental, and taxes

Performance testing challenges include identifying bottlenecks, simulating real-world scenarios, and analyzing results.

• Identifying bottlenecks in the system

• Simulating real-world scenarios to accurately test performance

• Analyzing results to identify areas for improvement

• Ensuring test environment is representative of production environment

• Managing test data and test scripts

• Dealing with network latency and other external factors

• Ensuring tests are repeatable and consistent

• Balancin...read more

Defects in BOPP film can include wrinkles, bubbles, and scratches. Resolving them requires understanding material properties and processing conditions.

• Identify the specific defect in the BOPP film, such as wrinkles, bubbles, or scratches.

• Analyze the root cause of the defect, which could be related to material properties or processing conditions.

• Adjust processing parameters like temperature, speed, or tension to minimize defects.

• Ensure proper handling and storage of BOPP film ...read more

There will be 19 matches in total in a knock out tournament with 20 teams.

• In a knock out tournament, each match eliminates one team.

• To determine the number of matches, subtract 1 from the total number of teams.

• For 20 teams, there will be 20 - 1 = 19 matches.

The question is unclear. Please provide more context.

Transport protocol in CAN J1939 is used for transmitting large data packets over the network.

• Transport protocol breaks down large data packets into smaller segments for transmission.

• It uses a flow control mechanism to ensure all segments are received and reassembled in the correct order.

• Examples of transport protocols in J1939 include BAM (Broadcast Announce Message) and RTS/CTS (Request To Send/Clear To Send).

No, DML operations cannot be performed on UDF functions.

• UDF functions are read-only and cannot modify the data in the database.

• DML operations can only be performed on tables or views.

• UDF functions can be used in SELECT statements to retrieve data.

• Examples of UDF functions include string manipulation, date calculations, and mathematical operations.

SQL query to select all columns from two tables.

• Use SELECT statement to select columns from tables.

• Use aliases to differentiate columns from different tables.

• Separate table names with comma in FROM clause.

Active agents initiate actions while passive agents respond to actions.

• Active agents are proactive while passive agents are reactive.

• Active agents initiate change while passive agents undergo change.

• Examples of active agents include enzymes, hormones, and neurotransmitters while examples of passive agents include water, air, and salt.

• Active agents are often associated with living organisms while passive agents are associated with non-living things.

Ultrasonic level transmitter uses sound waves to measure the level of liquid or solid in a container.

• The transmitter sends high-frequency sound waves towards the surface of the liquid or solid.

• The waves bounce back and are received by the transmitter.

• The time taken for the waves to return is measured and used to calculate the distance to the surface.

• The distance is then converted into a level measurement and transmitted to a control system.

• Ultrasonic level transmitters are co...read more

Linux system process, PKI, Cryptography, and Secure Boot process are all important components of secure computing.

• Linux system process refers to the way in which the operating system manages and executes programs and applications.

• PKI (Public Key Infrastructure) is a system for managing digital certificates and public-private key pairs to ensure secure communication.

• Cryptography involves the use of mathematical algorithms to secure data and communications.

• Secure Boot process i...read more

To design a tool like Google Looker, I would start by understanding the user's needs and requirements.

• Conduct user research to understand their needs and pain points

• Identify key features and functionalities required

• Create wireframes and prototypes to test and refine the design

• Collaborate with cross-functional teams to ensure seamless integration with existing systems

• Continuously gather feedback and iterate on the design

• Ensure scalability and security of the tool

Ambassador pattern is a Kubernetes design pattern that allows for external access to services.

• It involves using a sidecar container to proxy requests from outside the cluster to the service.

• The sidecar container can handle tasks such as authentication and load balancing.

• It allows for decoupling of the service from the external access mechanism.

• Examples include the use of Ambassador and Istio as implementations of the pattern.

A cursor is a database object used to manipulate data in a result set.

• A cursor is used to traverse through a result set one row at a time.

• It can be used to update or delete rows in a result set.

• Attributes of a cursor include its name, type, scrollability, and sensitivity.

• Examples of cursor types include forward-only, static, dynamic, and keyset-driven.

The 12 factors approach is a methodology for building modern, scalable, and maintainable microservices.

• Codebase: One codebase tracked in revision control, many deploys

• Dependencies: Explicitly declare and isolate dependencies

• Config: Store config in the environment

• Backing services: Treat backing services as attached resources

• Build, release, run: Strictly separate build and run stages

• Processes: Execute the app as one or more stateless processes

• Port binding: Export services via p...read more

1. Different types of welds and their applications. 2. Stress, strain, torque, buoyancy, etc.

• Different types of welds include butt welds, fillet welds, lap welds, etc.

• Butt welds are used to join two pieces of metal together end-to-end, while fillet welds are used to join two pieces of metal together at right angles.

• Lap welds are used to join two pieces of metal together that overlap each other.

• Stress is the force per unit area that a material is subjected to, while strain is ...read more

Read DTCs service in UDS is used to retrieve diagnostic trouble codes from a vehicle's electronic control unit.

• DTCs are codes that indicate a problem with a vehicle's systems or components

• The read DTCs service allows technicians to identify and diagnose issues with a vehicle

• The service is part of the Unified Diagnostic Services (UDS) protocol used in automotive diagnostics

• Examples of DTCs include P0300 (random/multiple cylinder misfire detected) and U0100 (lost communication ...read more

I have worked on Linux kernel versions 3.x, 4.x, and 5.x.

• Worked on Linux kernel versions 3.x, 4.x, and 5.x

• Experience with kernel development and debugging

• Familiar with kernel modules and drivers

L3 fabric is a network architecture that provides high-speed and low-latency connectivity between devices. COOP is a protocol used for failover and redundancy in networking.

• L3 fabric is a type of network architecture that uses Layer 3 routing to provide high-speed and low-latency connectivity between devices.

• It is designed to be scalable and flexible, allowing for easy expansion and modification of the network.

• COOP (Cluster Over the Wire Protocol) is a protocol used for failo...read more

Java 16 and Spring Boot 2.5 are the latest versions with new features and improvements.

• Java 16 introduces Records, Pattern Matching for instanceof, and Vector API among others.

• Spring Boot 2.5 includes support for Java 16, improved startup time, and better error messages.

• Other new features in Spring Boot 2.5 include support for Kotlin 1.5, Micrometer 1.7, and Spring Data 2021.0.

I am proficient in Civil3D and have extensive experience in using it for designing and drafting civil engineering projects.

• Expertise in creating and editing surfaces, alignments, profiles, and corridors

• Ability to generate 3D models and perform earthwork calculations

• Experience in creating plan and profile sheets, cross-sections, and quantity takeoffs

• Familiarity with Civil3D add-ons such as AutoTURN and Hydraflow

• Proficient in using Civil3D for various civil engineering projects...read more

A thread pool is a group of threads that can be reused to execute multiple tasks concurrently.

• Define a task interface that encapsulates the work to be done

• Create a queue to hold tasks

• Create a fixed number of threads in the pool

• Each thread should loop indefinitely, taking tasks from the queue and executing them

• Use synchronization primitives to ensure thread safety

• Consider using a thread-safe data structure for the task queue, such as a concurrent queue

• Consider using a thread-s...read more

CAN bus off is a state where communication between nodes on a CAN bus is lost. It can be recovered by resetting the bus or fixing the underlying issue.

• CAN bus off occurs when a node on the bus detects an error and goes into a fault state.

• This can happen due to issues like a short circuit, open circuit, or excessive noise on the bus.

• To recover from CAN bus off, the bus needs to be reset or the underlying issue needs to be fixed.

• Resetting the bus involves sending a sequence of ...read more

Leaf and spine architecture is a network topology used in Cisco ACI for scalable and efficient data center networking.

• Leaf switches connect to spine switches, which then connect to the core network.

• Leaf switches handle traffic within their own pod, while spine switches handle traffic between pods.

• ACI uses a 2-tier spine-leaf architecture for scalability and flexibility.

• The spine switches act as the routing backbone, while the leaf switches provide access to endpoints.

• ACI allo...read more

Linq expression to fetch desired results

• Use 'Where' to filter data based on conditions

• Use 'Select' to project data into desired format

• Use 'OrderBy' or 'OrderByDescending' to sort data

• Use 'Skip' and 'Take' to implement pagination

A functor is an object that can be treated as a function or a function pointer. It is used to encapsulate a function or a callable object.

• Functors are often used in C++ to implement function objects.

• They can be used as arguments to algorithms or as template parameters.

• Functors provide a way to customize behavior in generic programming.

• They can be used to define custom comparison functions for sorting or searching.

• Examples of functors include function pointers, lambda function...read more

SQL indexes are data structures that improve the speed of data retrieval operations by providing quick access to rows in a table.

• SQL indexes are created on columns in a table to speed up SELECT queries.

• When a query is executed, the SQL engine first checks if there is an index on the columns involved in the query.

• If an index is present, the SQL engine uses it to quickly locate the rows that satisfy the query conditions.

• The SQL execution order typically involves parsing, optimi...read more

Kafka is a distributed streaming platform that allows for real-time data processing. Data is not persisted permanently to optimize performance.

• Kafka is designed for real-time data processing and streaming, not for long-term storage.

• Data is stored in Kafka for a configurable amount of time, after which it is automatically deleted.

• Persisting data permanently would require additional storage and slow down performance.

• Kafka's architecture allows for high throughput and low latenc...read more

Creating sets, lists, and dictionaries from a given list.

• To create a set, use the set() function.

• To create a list, simply use square brackets [] and separate elements with commas.

• To create a dictionary, use curly braces {} and separate key-value pairs with colons and commas.

Roundabout parameters and values vary based on urban and rural settings.

• Urban roundabouts typically have smaller diameters and tighter curves than rural roundabouts.

• Rural roundabouts may have larger diameters and wider curves to accommodate larger vehicles.

• Speed limits, traffic volume, and pedestrian and cyclist activity also influence roundabout design.

• Roundabout parameters may include lane widths, splitter island widths, and apron widths.

• Designers may also consider landscap...read more

Database connection process in CodeIgniter involves configuring database settings in config file and loading database library.

• Configure database settings in config file

• Load database library

• Establish connection using database configuration

• Use database functions to perform CRUD operations

8D is a problem-solving methodology used to identify, correct, and prevent recurring problems.

• 8D stands for Eight Disciplines and is a structured problem-solving approach

• It involves identifying the problem, forming a team, implementing temporary and permanent solutions, and preventing recurrence

• An example of using 8D could be when I led a team to address a recurring quality issue in a manufacturing process by following the 8D steps

Partial view returns HTML string while render partial view writes directly to response stream.

• Partial view returns HTML string that can be used in the main view

• Render partial view writes directly to response stream

• Partial view can be used to render reusable components

• Render partial view can be used to render a partial view without a layout

MongoDB supports various data design patterns for record references.

• MongoDB supports embedding documents within other documents.

• MongoDB also supports referencing documents from other collections.

• The choice between embedding and referencing depends on the data access patterns.

• Embedding is preferred for one-to-one and one-to-many relationships.

• Referencing is preferred for many-to-many relationships.

• MongoDB also supports denormalization for performance optimization.

Yes, I have experience in Windows Server Administration.

• I have experience in managing and maintaining Windows Server 2012 and 2016.

• I am proficient in Active Directory, DNS, DHCP, and Group Policy Management.

• I have experience in configuring and troubleshooting network services and protocols.

• I am familiar with PowerShell scripting for automation and task scheduling.

• I have experience in managing virtualization technologies such as Hyper-V and VMware.