70+ Software Engineering Specialist Interview Questions and Answers

Python data structures are containers that hold data in an organized manner, each with its own advantages and differences.

• Python lists are versatile and can hold different data types.

• Tuples are immutable and can be used as keys in dictionaries.

• Sets are unordered and eliminate duplicate elements.

• Dictionaries store data in key-value pairs for efficient retrieval.

An array stores one type of element in sequential memory blocks for faster access.

• Arrays are useful for storing and accessing data in a specific order.

• They can be used to store numbers, characters, or other data types.

• Arrays can be multidimensional, allowing for more complex data structures.

• Accessing elements in an array is done using an index, starting at 0.

• Arrays can be resized dynamically in some programming languages.

Analytical functions are used to perform calculations across a set of rows. Rank assigns a unique rank to each row, while dens_rank assigns consecutive ranks.

• Analytical functions are used to perform calculations across a set of rows in a table.

• Rank function assigns a unique rank to each row based on the specified order.

• Dens_rank function assigns consecutive ranks to rows, leaving no gaps between ranks.

• Types of joins include inner join, outer join, left join, right join, etc.

• A...read more

The word count problem involves counting the frequency of words in a given text.

• Use Java 8 streams to split the text into words, map each word to a key-value pair with word as key and count as value, and then collect the results using groupingBy and counting collectors.

• Example: Stream.of(text.split("\\s+")).collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));

Map, filter and reduce are higher-order functions in JavaScript used to manipulate arrays.

• Map transforms each element of an array into a new array based on a provided function.

• Filter creates a new array with all elements that pass a test implemented by a provided function.

• Reduce applies a function to each element of an array and reduces the array to a single value.

• These functions are commonly used in functional programming and can make code more concise and readable.

• Example: ...read more

Spring Boot annotations are used to simplify the development process by providing metadata to the Spring framework.

• Annotations like @Component, @Service, @Repository are used to define object scopes in Spring Boot.

• Annotations like @Scope can be used to specify the scope of a bean, such as singleton or prototype.

• Annotations like @RequestScope, @SessionScope are used to define object scopes based on HTTP request or session.

• Annotations like @Configuration, @Bean are used to conf...read more

Axios is a third-party library that provides more features and flexibility than the fetch API.

• Axios allows for easy cancellation of requests.

• Axios has built-in support for handling request and response interceptors.

• Axios can handle request and response transformations.

• Axios has a larger community and more documentation than fetch API.

• Fetch API is built into modern browsers and requires no additional installation or setup.

• Fetch API has a simpler syntax than Axios.

List is dynamic and can be modified while array is fixed in size and cannot be modified.

• List can grow or shrink dynamically while array has a fixed size.

• List can contain elements of different data types while array can only contain elements of the same data type.

• List uses more memory than array due to its dynamic nature.

• Array is faster than list for accessing elements by index.

• Example: List - [1, 'hello', True], Array - [1, 2, 3]

• Example: List - ['apple', 'banana', 'orange'], ...read more

Python provides various libraries and modules to interact with databases, such as SQLite, MySQL, and PostgreSQL.

• Python's standard library includes the sqlite3 module for working with SQLite databases.

• For MySQL, the popular library is mysql-connector-python, which provides an interface to interact with MySQL databases.

• psycopg2 is a widely used library for connecting to PostgreSQL databases in Python.

• ORM (Object-Relational Mapping) libraries like SQLAlchemy can be used to abstr...read more

MongoDB is an open-source document database that provides high performance, scalability, and flexibility.

• MongoDB is a NoSQL database that stores data in flexible, JSON-like documents.

• It supports a rich query language and provides features like indexing, replication, and sharding.

• MongoDB is widely used in web applications, big data processing, and real-time analytics.

• Example: MongoDB is used by companies like Uber, Airbnb, and LinkedIn.

Annotations and keywords used in Spring Boot and Java

• The @Qualifier annotation is used in Spring to specify which bean should be autowired when multiple beans of the same type are present

• The @Value annotation is used in Spring to inject values from properties files or environment variables into Spring beans

• The transient keyword in Java is used to indicate that a field should not be serialized when the object is converted to a byte stream

• The volatile keyword in Java is used to...read more

To work in a pressurized environment and handle priority production bugs, one must prioritize tasks, communicate effectively, stay calm under pressure, and seek help when needed.

• Prioritize tasks based on their impact on the production environment

• Communicate effectively with team members and stakeholders to understand the urgency and impact of the bugs

• Stay calm under pressure and avoid making hasty decisions

• Break down complex problems into smaller, manageable tasks

• Seek help fr...read more

Object-oriented programming concepts in Java

• Encapsulation: Hiding implementation details and exposing only necessary information

• Inheritance: Creating new classes from existing ones, inheriting properties and methods

• Polymorphism: Ability of objects to take on multiple forms, method overloading and overriding

• Abstraction: Focusing on essential features and ignoring implementation details

• Class: Blueprint for creating objects, encapsulating data and behavior

• Object: Instance of a c...read more

Spring profiles allow for different configurations based on environment or application needs.

• Spring profiles are used to define different configurations for different environments or application needs.

• Profiles can be activated using the 'spring.profiles.active' property in application.properties or application.yml.

• Profiles can be defined using annotations like @Profile or by creating separate configuration files for each profile.

• Example: @Profile("dev") for development profil...read more

The deployment process in Salesforce involves moving changes from one environment to another in a controlled and systematic manner.

• Changes are typically made in a sandbox environment before being deployed to production.

• Deployment can be done manually or using tools like Salesforce DX or Change Sets.

• Version control systems like Git can also be used to track changes and facilitate deployment.

• Testing is an important part of the deployment process to ensure that changes do not br...read more

SOLID principles are a set of five principles in object-oriented programming. Worked on a project implementing SOLID principles. Faced challenges with tight deadlines and changing requirements.

• SOLID principles: Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, Dependency Inversion

• Implemented SOLID principles in a project by breaking down functionality into smaller, cohesive classes with clear responsibilities

• Challenges faced included adapting to ...read more

I have worked on a variety of technologies including Java, Python, SQL, and AWS.

• Java

• Python

• SQL

• AWS

Routing, hooks, service, and directives are all important concepts in software engineering.

• Routing refers to the process of determining how an application responds to a client request.

• Hooks are functions that allow developers to tap into the lifecycle of a component or application.

• Services are reusable pieces of code that provide functionality to an application.

• Directives are markers on a DOM element that tell AngularJS to attach a specified behavior to that element.

Use a hash set to keep track of unique elements while iterating through the array.

• Create a hash set to store unique elements.

• Iterate through the array and check if each element is already in the hash set.

• If the element is not in the hash set, add it to the hash set.

• If the element is already in the hash set, it is a duplicate entry.

Dunder methods are special methods in Python that start and end with double underscores.

• Dunder methods are also known as magic methods or special methods.

• They are used to define behavior for built-in Python operations.

• Examples include __init__ for object initialization and __str__ for string representation.

• Dunder methods can be used to customize classes and objects in Python.

Functional components are stateless and use functional programming concepts, while class components have state and lifecycle methods.

• Functional components are simpler and easier to read/write.

• Class components have access to lifecycle methods like componentDidMount.

• Functional components can use hooks like useState and useEffect.

• Class components are typically used for more complex components with state management.

Developed a web application for online shopping with user authentication and payment integration.

• Frontend developed using React.js with responsive design for different screen sizes

• Backend built with Node.js and Express.js for handling API requests

• Database used MongoDB for storing product information and user data

• Implemented user authentication using JWT tokens

• Integrated payment gateway using Stripe API for secure transactions

HOC stands for Higher Order Component in React.

• HOC is a function that takes a component and returns a new component with additional functionality.

• It is used for code reuse, logic abstraction, and render hijacking.

• Examples of HOCs are connect() and withRouter() in React-Redux and React-Router respectively.

Implementing cache in core Java involves using data structures like HashMap or LinkedHashMap.

• Use HashMap or LinkedHashMap to store key-value pairs in memory

• Implement a mechanism to check if the data is already in cache before fetching from the main source

• Set a maximum size for the cache and implement a strategy to evict least recently used items if the cache is full

Use Callable interface to return Object from Thread

• Implement Callable interface instead of Runnable

• Use ExecutorService to submit Callable and get Future object

• Call get() method on Future object to retrieve the returned Object

Transient, Scoped, and Singleton are different types of dependency injection lifetimes in software engineering.

• Transient: New instance is created every time it is requested. Suitable for lightweight objects with no shared state.

• Scoped: Instance is created once per request within the scope. Suitable for objects that are shared within a single request.

• Singleton: Single instance is created and shared throughout the application. Suitable for objects that are expensive to create o...read more

Joins in SQL are used to combine rows from two or more tables based on related columns.

• Joins are used to retrieve data from multiple tables in a single query.

• Common types of joins include inner join, left join, right join, and full outer join.

• Joins are performed using the JOIN keyword and specifying the join condition.

• Example: SELECT * FROM table1 JOIN table2 ON table1.column = table2.column;

Automating software package creation and deployment process

• Use continuous integration/continuous deployment (CI/CD) tools like Jenkins or GitLab CI

• Create scripts for building and packaging software

• Utilize configuration management tools like Ansible or Puppet for automated deployment

• Implement version control to track changes and rollback if needed

To create a service in Angular, you can use the 'ng generate service' command or manually create a service file.

• Use the Angular CLI command 'ng generate service serviceName' to create a new service file

• Manually create a service file by creating a new TypeScript file with the '.service.ts' extension

• Inject the service into components or other services by adding it to the providers array in the @Injectable decorator

• Define methods and properties in the service class to provide fu...read more

Count the number of duplicates in an array of strings.

• Iterate through the array and use a hashmap to store the count of each string.

• Check the count of each string in the hashmap to determine duplicates.

• Return the total count of duplicates found.

Angular life cycle hooks are methods that allow you to tap into specific points in a component's life cycle.

• ngOnChanges: called when an input property changes

• ngOnInit: called once after the first ngOnChanges

• ngDoCheck: called during every change detection run

• ngAfterContentInit: called after content is projected into the component

• ngAfterContentChecked: called after every check of projected content

• ngAfterViewInit: called after the component's view has been initialized

• ngAfterView...read more

A machine learning model is a mathematical algorithm that learns from data to make predictions or decisions.

• ML models can be supervised, unsupervised, or semi-supervised

• Examples include linear regression, decision trees, neural networks, and support vector machines

• Models can be used for classification, regression, clustering, and anomaly detection

To center a div, use CSS properties like margin, display, and text-align.

• Set margin to auto on left and right sides

• Set display to flex and justify-content to center

• Set text-align to center for inline elements

Pure pipes do not have any side effects and always return the same output for the same input, while impure pipes can have side effects and may not return the same output for the same input.

• Pure pipes are stateless and deterministic.

• Impure pipes can have side effects like modifying global variables or making network requests.

• Pure pipes always return the same output for the same input.

• Impure pipes may not return the same output for the same input.

• Examples of pure pipes include ...read more

QuickSort is a popular sorting algorithm that uses divide and conquer approach.

• Divide the array into two sub-arrays based on a pivot element

• Recursively sort the sub-arrays

• Combine the sorted sub-arrays to get the final sorted array

• Time complexity: O(n log n) in average case and O(n^2) in worst case

• Example: [5, 2, 9, 3, 7, 6, 8, 1, 4] -> [1, 2, 3, 4, 5, 6, 7, 8, 9]

Implementation class for ArrayList in Java

• Create a class named ArrayList with a private array to store elements

• Implement methods like add, remove, get, size, etc.

• Handle resizing of the array when needed

• Use generics to allow storing any type of objects

• Here is a simple example: public class ArrayList { private Object[] array; ... }

Cpp programs can use static, stack, or heap memory allocation for variables and objects.

• Static memory allocation is done at compile time and is used for variables declared outside functions.

• Stack memory allocation is done at runtime and is used for variables declared inside functions.

• Heap memory allocation is done at runtime and is used for dynamic memory allocation using new and delete operators.

HashSet is an unordered collection that uses hashing to store and retrieve elements efficiently.

• HashSet internally uses a HashMap to store its elements.

• Each element is stored as a key in the HashMap with a fixed value.

• When adding an element, its hash code is calculated and used to determine the bucket in the HashMap where it will be stored.

• If multiple elements have the same hash code, they are stored in the same bucket as a linked list.

• To retrieve an element, its hash code is...read more

HashMap works internally by using a hash function to map keys to their corresponding values in an array of linked lists.

• HashMap uses a hash function to determine the index of the key-value pair in the array.

• Collisions can occur when multiple keys hash to the same index, which is resolved by using linked lists at each index.

• When retrieving a value, the hash function is used to find the correct index and then the linked list is searched for the key.

• HashMap dynamically resizes w...read more

Convert a given digit to its Roman numeral equivalent.

• Create a mapping of digit to Roman numeral values.

• Iterate through the mapping to find the largest Roman numeral that fits the given digit.

• Subtract the Roman numeral value from the digit and repeat until the digit becomes 0.

No, static class cannot be inherited.

• Static classes cannot be inherited because they are sealed by default.

• Static classes are used to create utility classes with static members.

• Example: Math class in C# is a static class with static methods like Math.Max() and Math.Min().

HashSet internally uses a HashMap to store elements as keys with a dummy value.

• HashSet uses a HashMap to store elements as keys with a dummy value.

• It does not allow duplicate elements.

• Elements are stored based on their hash code for faster retrieval.

• HashSet does not maintain insertion order.

Spring Cloud interface is a set of tools for building cloud-native applications.

• Spring Cloud provides tools for building distributed systems and microservices

• It includes features like service discovery, circuit breakers, and distributed tracing

• Spring Cloud interfaces with popular cloud platforms like AWS, Azure, and Google Cloud

• Example: Spring Cloud Netflix provides integration with Netflix OSS components like Eureka and Hystrix

Garbage collection in Java is the process of automatically reclaiming memory that is no longer in use by the program.

• Garbage collection is performed by the JVM to free up memory occupied by objects that are no longer referenced by the program.

• It helps in preventing memory leaks and managing memory efficiently.

• Java provides automatic garbage collection, so developers do not have to manually free up memory.

• Examples of garbage collection algorithms in Java include Mark and Sweep...read more

SOLID principles are a set of five design principles that help make software designs more understandable, flexible, and maintainable.

• Single Responsibility Principle (SRP) - A class should have only one reason to change.

• Open/Closed Principle (OCP) - Software entities should be open for extension but closed for modification.

• Liskov Substitution Principle (LSP) - Objects of a superclass should be replaceable with objects of its subclasses without affecting the functionality.

• Inter...read more

An interceptor is a software component that intercepts incoming and outgoing requests, allowing for manipulation or monitoring of the data.

• Interceptors are commonly used in web development frameworks to add cross-cutting concerns such as logging, authentication, or caching.

• They can be used to modify the request or response before it reaches the intended destination.

• Examples include HTTP interceptors in AngularJS or request interceptors in Axios.

A pointer is a variable that stores the memory address of another variable.

• Pointers are used to indirectly access and manipulate data in memory.

• They are commonly used in programming languages like C and C++.

• Example: int *ptr; // declares a pointer to an integer variable