500+ Lead Engineer Interview Questions and Answers

Form the largest string using a, b, and c with the condition that 3 (a, b, or c) can't be together.

• Start with the most frequent letter and alternate with the other two.

• If there are two letters with the same frequency, start with the one that has the least number of adjacent letters.

• Example: 'abcabcab' is not valid, but 'abacbac' is valid and larger.

Led a team to develop a new feature for a mobile app

• Identified the need for a new feature based on user feedback

• Created a detailed plan outlining tasks and deadlines

• Assigned tasks to team members based on their strengths

• Regularly communicated with team members to track progress and address any issues

• Conducted testing and gathered feedback to make necessary improvements

• Successfully launched the feature on schedule

The default connection pooling in Spring Boot is HikariCP, which can be customized through properties in the application.properties file.

• HikariCP is the default connection pooling library in Spring Boot, known for its high performance and low overhead.

• To customize the connection pooling, you can modify properties like 'spring.datasource.hikari.*' in the application.properties file.

• For example, you can set maximum pool size, connection timeout, idle timeout, and other paramete...read more

Create end to end pipelines in Data Factory with SQL and ASQL as source and target respectively.

• Use Copy Data activity to move data from SQL source to ASQL target

• Define linked services for SQL and ASQL in Data Factory

• Create datasets for SQL and ASQL tables

• Map columns between source and target datasets

• Configure data flow activities for any transformations needed

Service discovery is the process of automatically locating services in a network. Azure provides Azure Service Fabric for service discovery.

• Service discovery helps in locating services in a network without hardcoding their addresses.

• Azure Service Fabric provides a built-in service discovery mechanism.

• Service Fabric uses naming conventions and DNS resolution to discover services.

• Service Fabric also provides APIs for service discovery.

• Other tools for service discovery in Azure ...read more

Selecting sheet metal for control panels involves material choice, design considerations, and manufacturing processes.

• Material selection: Common materials include aluminum for lightweight applications and stainless steel for corrosion resistance.

• Thickness considerations: Thicker panels provide durability but increase weight; balance is key based on application.

• Environmental factors: Consider exposure to moisture, chemicals, or extreme temperatures when selecting materials.

• Man...read more

Use a magnetic level gauge to measure the level of a vertical vessel for calibration.

• Install a magnetic level gauge on the vertical vessel.

• Ensure the gauge is properly calibrated and zeroed.

• Take readings at various levels and record the corresponding magnetic field strengths.

• Compare the readings to a calibration curve to determine the actual level of the vessel.

• Adjust the gauge if necessary and repeat the process until accurate readings are obtained.

We are using Java 11 in our project, which includes features like local variable type inference, HTTP client API, and improved security.

• Java 11 introduced local variable type inference, allowing the compiler to infer the type of a variable based on the initializer.

• The HTTP client API in Java 11 provides a more modern and flexible way to send HTTP requests and handle responses.

• Java 11 also includes improved security features, such as TLS 1.3 support and stronger algorithms for...read more

We are using Spring Boot version 2.5.2 in our project, which includes features like improved startup performance, enhanced actuator endpoints, and updated dependencies.

• Spring Boot 2.5.2 offers improved startup performance compared to previous versions.

• Enhanced actuator endpoints provide better monitoring and management capabilities.

• Updated dependencies ensure compatibility with the latest libraries and frameworks.

The number of handshakes in a party with 30 members where each person shakes hands with every other person once.

• Calculate the total number of handshakes using the formula n(n-1)/2, where n is the number of people.

• Substitute n=30 in the formula to get the total number of handshakes.

• Total handshakes = 30(30-1)/2 = 435 handshakes.

Test engineers encounter various scenarios when troubleshooting, such as software bugs, hardware malfunctions, and network issues.

• Identifying and resolving software bugs in the code

• Troubleshooting hardware malfunctions in devices or equipment

• Resolving network issues affecting communication between systems

Technical questions related to switching, VLANs, and Python string slicing for Lead Engineer position.

• A loop in switching occurs when a broadcast packet is forwarded endlessly between switches.

• To say VLAN 200 is working on a switch, you can check the VLAN database or use the show vlan command.

• An ethernet frame is tagged when it has a VLAN ID added to its header, and untagged when it does not.

• Regarding the project, provide details on the scope, timeline, and deliverables.

• Pytho...read more

Using Java Stream API to group employees by gender and count them.

• Use List<Employee> to hold employee data.

• Utilize Stream API's collect method with groupingBy.

• Example: Map<Gender, Long> genderCount = employees.stream().collect(Collectors.groupingBy(Employee::getGender, Collectors.counting()));

• This will give a map with gender as key and count as value.

Java memory management, string pool, Java 8 features, multi threading, design patterns

• Java memory management involves managing memory allocation for heap and stack. Heap is used for storing objects and is managed by garbage collector. Stack is used for method calls and local variables.

• String pool is a special area in heap memory where String literals are stored to optimize memory usage. Strings with same values are stored only once in the pool.

• Java 8 features include lambda e...read more

Configuring a frequency input pin in MCAL and its flow till application layer

• Frequency input pin is configured in MCAL using configuration tools like AUTOSAR

• MCAL provides low-level drivers for hardware access

• The configured pin is then used by the HAL layer to provide higher-level drivers

• The application layer uses the HAL drivers to access the pin for frequency measurement

• The flow involves configuration, driver generation, and application usage

Azure functions are event-driven, serverless compute solutions while worker processes are long-running processes.

• Azure functions are triggered by events such as HTTP requests, messages in a queue, or changes in a database.

• Worker processes are long-running processes that perform a specific task continuously.

• Azure functions are serverless, meaning that the infrastructure is managed by Azure.

• Worker processes require a server or virtual machine to run on.

• Azure functions are bille...read more

Diagonally iterate through and print elements of a 2D array of strings.

• Use nested loops to iterate through rows and columns of the 2D array.

• Calculate the diagonal elements by incrementing row and column indices together.

• Print the elements as you iterate through the diagonal of the array.

Best practices for optimizing a Spring Boot application

• Use Spring Boot Actuator to monitor and manage application performance

• Implement caching mechanisms like Spring Cache to reduce database calls

• Optimize database queries and indexes for better performance

• Use asynchronous processing with Spring's @Async annotation for non-blocking operations

• Profile and analyze application performance using tools like VisualVM or JProfiler

A heap dump is a snapshot of the memory usage of a Java application at a specific point in time.

• Heap dumps can be generated using tools like jmap or VisualVM.

• They provide detailed information about objects in memory, their sizes, and references.

• Analyzing a heap dump can help identify memory leaks by pinpointing objects that are consuming excessive memory.

• Common signs of memory leaks in a heap dump include a large number of objects of the same type or objects that should have ...read more

Integrating third party libraries involves adding the library to the project dependencies and configuring it for use.

• Add the library as a dependency in the project's build file (e.g. Gradle, Maven)

• Import the necessary classes or functions from the library in your code

• Configure any necessary settings or initialization code for the library to work properly

• Ensure compatibility with the project's existing codebase and dependencies

• Update the project's documentation to include info...read more

MLAG is a protocol used for creating a loop-free network topology. LACP and PAGP are link aggregation protocols.

• MLAG stands for Multi-Chassis Link Aggregation Group.

• It allows multiple switches to appear as a single logical switch to the connected devices.

• LACP (Link Aggregation Control Protocol) is an IEEE standard protocol used for link aggregation.

• PAGP (Port Aggregation Protocol) is a Cisco proprietary protocol used for link aggregation.

• Both LACP and PAGP are used to bundle ...read more

To design a power supply, one must consider the requirements and specifications of the hardware. Testing involves verifying the output voltage and current, efficiency, and reliability.

• Determine the power requirements of the hardware

• Select appropriate components for the power supply

• Design the circuit and layout

• Simulate the circuit to ensure proper functionality

• Prototype and test the power supply

• Verify the output voltage and current meet the hardware requirements

• Measure the eff...read more

Ground clearance of 11KV Line, network cleaning, and AT&C loss calculation explained.

• Ground clearance of 11KV Line is typically around 5.5 meters to ensure safety from accidental contact.

• Network cleaning refers to the process of removing unwanted or unnecessary data, files, or connections from a network to improve performance and security.

• AT&C loss stands for Aggregate Technical and Commercial loss, which is the difference between the amount of electricity supplied to an area...read more

I would use Spring Boot to create a stateless microservice with CRUD API, returning appropriate responses for each operation.

• Use @RestController annotation to define RESTful endpoints

• Implement methods for Create, Read, Update, and Delete operations using @PostMapping, @GetMapping, @PutMapping, @DeleteMapping annotations

• Return appropriate HTTP status codes (e.g. 200 for successful operation, 404 for not found, 400 for bad request)

• Return response entities with relevant data (e....read more

Java's multithreading features enhance concurrency with Executor, CompletableFuture, and async programming capabilities.

• Executor Framework: Simplifies thread management with thread pools. Example: Executors.newFixedThreadPool(5).

• Runnable and Callable: Runnable for tasks without return values; Callable for tasks with return values. Example: Callable<Integer> task = () -> 42;

• CompletableFuture: Allows non-blocking asynchronous programming. Example: CompletableFuture.supplyAsync(...read more

High-Level Integration Testing (HSIT) and Unit Testing involve various standards and methods to ensure software quality and functionality.

• HSIT focuses on testing the interactions between integrated components or systems, ensuring they work together as intended.

• Unit Testing involves testing individual components or functions in isolation to verify their correctness, often using frameworks like JUnit or NUnit.

• Common standards for HSIT include IEEE 829 for test documentation and...read more

A real-time multi-camera system that captures and combines images into a single composite image.

• Use multiple cameras positioned at different angles to capture images simultaneously.

• Implement a synchronization mechanism to ensure all cameras capture images at the same time.

• Utilize image processing techniques to align and stitch images together seamlessly.

• Consider using a central processing unit (CPU) or graphics processing unit (GPU) for real-time image processing.

• Example: A 3...read more