Programs
Nowadays, full-stack developers are in high demand in the fast-paced technology industry. These professionals can work on both front-end and back-end development. They are an important part of any programming team. Their duties include making websites that are functional and easy to use.
This blog post will discuss what you need to become a full-stack developer. We will focus on the kind of skills required for a given role as well as provide comprehensive sets of interview questions with answers for beginners and experienced developers. If you have an upcoming job interview or just want to boost your knowledge of full-stack development, then go through our guide!
A full-stack developer is a versatile IT professional who works on both sides of web development: front-end & back-end. They can perform various tasks such as user interface design, database management, and server-side operations, among others. This means they have the capacity to make everything about software development a success by ensuring it works well enough, has fast performance rates, and looks attractive.
These specialists employ different techniques plus frameworks when finishing final products which users can interact with. Take an example of someone conversant with developing top-most responsive pages like HTML5, CSS3, and JavaScript, including processing form response at the backend and storing response into the database too.
| Aspect | Agile Methodology | Waterfall Methodology |
| Approach | Iterative, incremental development with regular feedback | Linear, sequential approach with defined phases |
| Flexibility | Highly flexible, changes can be incorporated throughout the project | Rigid, changes are difficult to implement once a phase is completed |
| Customer Involvement | High, customers provide continuous feedback | Low, customer involvement is typically at the beginning and end |
| Risk Management | Continuous assessment and mitigation of risks | Risks are identified at the beginning, with limited reassessment |
| Use Case | Best for projects with evolving requirements | Best for projects with clearly defined and unchanging requirements |
CORS (Cross-Origin Resource Sharing) is a security feature implemented by web browsers that allows or restricts resources (like fonts, scripts, or data) on a web page from being requested from another domain. It’s a way to control access to resources on a server from a different origin. For instance, if a webpage on domain-a.com wants to fetch data from domain-b.com, CORS headers determine whether the request should be allowed or blocked.
Both <div> and <span> are HTML elements used for grouping and styling content, but they serve different purposes.
| Feature | <div> | <span> |
| Display | Block-level | Inline-level |
| Width | Occupies full width | Occupies only the width of its content |
| Usage | Wrapping sections of content like paragraphs | Wrapping small portions of content like text |
| Starts New Line | Yes | No |
An Iframe (Inline Frame) in HTML is an element that lets you put another HTML document inside the current page. This could be advertisements, videos or other websites which are added as small sections in your webpage for example.
Example:
| Aspect | Attributes | Properties |
| Definition | Defined in HTML markup | Accessed and manipulated through JavaScript |
| Example | <img src=”image.jpg” alt=”image”> | document.getElementById(‘myImage’).src = “new.jpg”; |
| Persistence | Static, doesn’t change unless updated via script | Dynamic, reflects the current state of the element |
Multithreading allows for the simultaneous execution of multiple threads within a single process. It is useful when undertaking tasks like parallel processing, handling multiple tasks simultaneously and running background tasks without affecting the performance of the main thread.
Example in Python:
An Application Server is software that provides an environment for running web applications. It handles the business logic, manages database connections, and serves dynamic content to users. Examples include Apache Tomcat, Microsoft IIS, and JBoss.
| Design Pattern Category | Examples | Purpose |
| Creational Patterns | Singleton, Factory Method, Builder | Deal with object creation mechanisms |
| Structural Patterns | Adapter, Composite, Proxy | Handle object composition and structure |
| Behavioral Patterns | Observer, Strategy, Command | Manage object interactions and responsibilities |
| Technology Stack | Frontend | Backend | Database | Tools |
| MEAN Stack | Angular | Node.js | MongoDB | Express.js |
| MERN Stack | React | Node.js | MongoDB | Express.js |
| LAMP Stack | HTML/CSS/JavaScript | PHP | MySQL | Apache Server |
| Django Stack | HTML/CSS/JavaScript | Python (Django) | PostgreSQL/MySQL | Django ORM |
SDLC (Software Development Life Cycle) is a structured process for developing software, ensuring high quality and meeting user requirements. It involves the following stages:
| Aspect | JavaScript | TypeScript |
| Type Checking | Dynamically typed | Statically typed; type errors are caught at compile-time |
| Syntax | Basic, can be prone to runtime errors | Extends JavaScript syntax, adding type annotations and interfaces |
| Tooling | Supported by all modern browsers, requires no compilation | Requires a transpiler like tsc to compile TypeScript to JavaScript |
| Error Handling | Errors are caught at runtime | Errors can be caught during development, reducing runtime errors |
| Use Case | Suitable for small to medium-sized projects | Ideal for large-scale applications where maintainability is key |
MongoDB is a NoSQL database known for its flexibility and scalability. Key features include:
CSS (Cascading Style Sheets) is a language used to describe the presentation of a web page. It controls the layout, colours, fonts, and overall visual appearance of HTML elements. CSS allows developers to create consistent and visually appealing web pages that work across different devices and screen sizes.
The CSS Clear Property is used to control the behaviour of floating elements. It specifies whether an element should be moved down below floating elements that precede it, ensuring that it does not overlap or wrap around the floated elements.
Example:
| Aspect | RGB | RGBA |
| Definition | Stands for Red, Green, Blue | Stands for Red, Green, Blue, Alpha |
| Color Channels | 3 colour channels (Red, Green, Blue) | 4 channels (Red, Green, Blue, and Alpha for opacity) |
| Opacity Control | Does not support opacity | Supports opacity through the Alpha channel |
| Usage Example | rgb(255, 0, 0) for solid red colour | rgba(255, 0, 0, 0.5) for semi-transparent red colour |
My favourite coding language is Python. It’s versatile, easy to read, and has a vast range of libraries that make it suitable for tasks ranging from web development to data science. Python’s simplicity and readability make it an excellent choice for both beginners and experienced developers. Its large community and extensive documentation further enhance its usability.
| Aspect | GraphQL | REST (Representational State Transfer) |
| Data fetching | client specifies exactly what data it needs | The server defines the data structure in each response |
| Flexibility | highly flexible; allows fetching multiple resources in a single request | less flexible; often requires multiple requests to fetch related resources |
| Versioning | no versioning needed; schema evolves with time | requires versioning as APIs change |
| Aspect | Thread | Process |
| Definition | a lightweight, smaller unit of a process | a heavy, independent program in execution |
| Memory | shares memory with other threads within the same process | has its own separate memory space |
| Communication | easier to communicate between threads | inter-process communication is more complex |
| Crash impact | a crash in one thread may not affect others | a crash in a process may terminate the entire process |
Optimising an existing website involves several steps:
| Aspect | React | Angular |
| Type | JavaScript library focused on building UI components | Full-fledged framework for building single-page applications |
| Learning Curve | Easier to learn, especially for developers familiar with JavaScript | Steeper learning curve due to more concepts and tools |
| Flexibility | Highly flexible; can be integrated with other libraries and frameworks | More opinionated with built-in tools and patterns |
| Data Binding | Uses one-way data binding | Supports two-way data binding |
| Performance | Generally faster due to virtual DOM and focused updates | Can be slower for large-scale applications due to real DOM manipulation |
| Use Case | Best for building component-based UI applications | Best for large, enterprise-level applications with complex requirements |
Continuous integration (CI) typically consists of several steps that ensure code quality and smooth integration:
| Aspect | GET Method | POST Method |
| Purpose | Retrieves data from the server | Sends data to the server to create/update a resource |
| Data in URL | Appends data to the URL as query parameters | Sends data in the request body, not visible in the URL |
| Idempotency | Idempotent, meaning multiple identical requests should have the same effect | Not necessarily idempotent, multiple identical requests may result in different outcomes |
| Data Length | Limited by URL length restrictions | No significant limit on data length |
| Security | Less secure, as data is visible in the URL | More secure, as data is hidden in the request body |
| Use Case | Ideal for fetching data, such as loading a webpage | Ideal for submitting form data, such as login credentials |
To find a memory leak, follow these steps:
| Aspect | INNER JOIN | OUTER JOIN |
| Purpose | Returns only the rows with matching values in both tables | Returns all rows from one table and matched rows from the other |
| Matching Records | Only includes rows where there is a match in both tables | Includes rows even if there is no match in one of the tables |
| Types | Single type (INNER JOIN) | Multiple types (LEFT OUTER JOIN, RIGHT OUTER JOIN, FULL OUTER JOIN) |
| Use Case | Ideal when you only need data common to both tables | Ideal when you need all data from one table, regardless of matches in the other table |
I am quite comfortable with design patterns. I have experience implementing various design patterns, such as Singleton, Factory, Observer, and MVC, in different projects. I understand when to use each pattern and how they contribute to code reusability, maintainability, and flexibility.
Successful integration requires careful planning and attention to several key factors:
| Aspect | HTTP (Hypertext Transfer Protocol) | HTTPS (Hypertext Transfer Protocol Secure) |
| Security | Data is transmitted in plain text, which can be intercepted | Data is encrypted, providing a secure connection |
| Port | Uses port 80 by default | Uses port 443 by default |
| Certificates | No SSL/TLS certificate required | Requires an SSL/TLS certificate |
| Use Case | Suitable for non-sensitive information exchange | Essential for sensitive transactions like banking, login forms |
I prefer CommonJS for server-side JavaScript, particularly with Node.js, because it’s widely supported and follows a synchronous loading model, which is straightforward and easier to debug. AMD is more suitable for browser-based development due to its asynchronous loading, which can improve performance in the browser environment. The choice depends on the environment and specific use case, but CommonJS is more commonly used in server-side development.
| Aspect | Monolithic Architecture | Microservices Architecture |
| Structure | Single, unified codebase | Composed of small, independent services |
| Deployment | Deployed as a single unit | Services are deployed independently |
| Scalability | Harder to scale, requires scaling the entire application | Easier to scale individual services as needed |
| Technology Stack | Typically uses a single technology stack | Allows for diverse technology stacks per service |
| Use Case | Suitable for small to medium-sized applications | Best for large, complex applications with multiple independent components |
To optimise a website for efficiency and scalability, consider the following strategies:
| Aspect | Normalisation | Denormalization |
| Purpose | Organises data to reduce redundancy and improve data integrity | Introduces redundancy to improve read performance and reduce query complexity |
| Data Structure | Divides data into multiple related tables | Combines related tables into fewer tables |
| Complexity | More complex queries, as data is spread across multiple tables | Simpler queries, as data is often in a single table |
| Use Case | Ideal for transactional systems where data integrity is crucial | Ideal for read-heavy systems where performance is a priority |
| Storage | Requires less storage space | May require more storage space due to redundancy |
Flask, a Python lightweight web framework, helps developers build web apps quickly. It is simple to use and has fewer built-in features offering flexibility. Flask adheres to the standard of WSGI (Web Server Gateway Interface) and comes with basic tools such as routing, request handling, and templating which makes it ideal for small to medium projects or for developers who like picking their own libraries.
ReactJS is a library in JavaScript created by Facebook for creating user interfaces, specifically single-page applications. This means that it allows developers to create reusable UI components, thus making it easier to manage the view layer of an application. React applies virtual DOM so that it can efficiently update and render components resulting in better performance in dynamic web applications.
| Aspect | Git Merge | Git Rebase |
| Functionality | Combines two branches by creating a new merge commit | Re-applies commits from one branch onto another, creating a linear history |
| Commit History | Preserves the full history of both branches, including the merge commit | Rewrites commit history, creating a clean, linear history |
| Conflict Resolution | Conflicts are resolved during the merge process | Conflicts are resolved during the rebase process |
| Use Case | Ideal when you want to preserve the history and context of all commits | Ideal for maintaining a clean project history, often used before merging a feature branch |
| Result | Maintains a branch structure in history | Results in a linear history, as if all changes were made sequentially |
Next.js, a React framework, enables server-side rendering and static site generation for React apps. It provides routing capabilities, automatic code splitting, server-side rendering features etc., thus reducing development time. Use Next JS to build high-performance SEO-friendly web apps.
| Aspect | MVC (Model-View-Controller) | MVVM (Model-View-ViewModel) |
| Structure | Separates application into Model, View, and Controller | Separates application into Model, View, and ViewModel |
| Data Binding | Typically uses one-way data binding | Typically uses two-way data binding |
| Component Responsibilities | Controller handles user input and updates the Model | ViewModel handles most of the presentation logic, binding View and Model |
| Ease of Testing | Controllers can be difficult to test due to tight coupling with Views | Easier to test as ViewModels can be tested independently |
| Use Case | Suitable for traditional web applications | Suitable for modern, data-driven applications, especially with frameworks like Angular |
Django is a high-level Python-based web framework that promotes quick development as well as clean pragmatic design principles. This framework employs the Model-View-Template (MVT) architectural pattern and has in-built facilities such as user authentication, database interactions and URL routing among others. It scales well, and guarantees the safety of your systems while still being fully documented.
MySQL is an open-source Relational Database Management System (RDBMS) that uses Structured Query Language (SQL) for data management purposes. It is widely used in web applications where data needs to be stored or retrieved because it supports features like transactions, indexing and replication. This popularity lies in its reliability, scalability and simplicity hence ideal for both small-scale and large-scale applications.
| Aspect | List | Array |
| Data type flexibility | Can store different data types in a single list | Typically stores elements of the same data type (when using numpy arrays) |
| Built-in type | Python’s built-in data structure | Requires importing the array module or numpy |
| Functionality | Supports a wide range of operations and methods | More limited in operations compared to lists, but optimised for numerical computations |
| Usage | Ideal for general-purpose data storage | Ideal for numerical operations where performance is critical |
| Memory efficiency | Less memory efficient compared to arrays | More memory efficient, especially for large data sets |
| Aspect | Structured Databases | Unstructured Databases |
| Data Format | Stores data in a fixed, predefined format (e.g., tables with rows and columns) | Stores data in a flexible, undefined format (e.g., documents, images, videos) |
| Schema | Requires a defined schema before data is entered | No predefined schema; data can be stored as-is |
| Query Language | Uses structured query languages like SQL | Uses various query mechanisms, often specific to the database |
| Use Case | Best for applications requiring consistent, structured data | Best for applications dealing with large volumes of varied data |
The event loop on Node.js handles asynchronous operations on this platform. To manage non-blocking I/O operations on Node.js’ single-threaded approach, the event loop comes to use. It keeps checking the call stack and callback queue and then executes callbacks when the former is empty to ensure efficient execution of asynchronous code.
In certain scenarios, particularly those with complex queries requiring multiple REST API calls, GraphQL can be faster compared to REST API. Clients in GraphQL can request specific data they require which may reduce how much data is being transferred and how many network requests are made. Performance varies depending on implementation details, query complexity, and how the server handles those queries. For simple single-resource requests, rest can be simpler and faster.
| Aspect | Server-side Scripting | Client-side Scripting |
| Execution | Runs on the server before the content is sent to the client’s browser | Runs on the client’s browser after the content is loaded |
| Languages | Examples include PHP, Python, Ruby, Node.js | Examples include JavaScript, HTML, CSS |
| Use Cases | Used for database interactions, server logic, and dynamic content generation | Used for user interface interactions, form validations, and enhancing user experience |
| Security | Generally more secure, as code is hidden from the client | Less secure, as code is visible and can be modified by the client |
| Aspect | SQL Databases | NoSQL Databases |
| Data Model | Relational, uses tables with rows and columns | Non-relational, uses document, key-value, graph, or columnar models |
| Schema | Requires a fixed schema before data is added | Flexible schema, allowing dynamic and unstructured data |
| Query Language | Structured Query Language (SQL) | Varies by database (e.g., MongoDB uses BSON queries, Cassandra uses CQL) |
| Scalability | Vertical scaling (adding more power to a single server) | Horizontal scaling (adding more servers) |
| Examples | MySQL, PostgreSQL, Oracle | MongoDB, Cassandra, Redis, Elasticsearch |
‘use strict’ is a directive in JavaScript that enables strict mode, which helps catch common coding errors and ‘unsafe’ actions, such as assigning values to undeclared variables. It makes debugging easier and helps avoid potentially problematic JavaScript features.
Example:
Using strict mode is recommended as it promotes better coding practices and can prevent subtle bugs.
| Aspect | Synchronous Programming | Asynchronous Programming |
| Execution | Code is executed sequentially, one operation at a time | Code allows multiple operations to run concurrently |
| Blocking | Operations block the next operation until complete | Operations don’t block; they proceed to the next task while waiting |
| Use Case | Simple, linear tasks where each step depends on the previous | Tasks involving I/O operations, timers, or network requests |
| Complexity | Easier to write and understand | Can be more complex due to callbacks, promises, or async/await |
| Performance | Can be slower as it waits for each operation to complete | Typically faster and more efficient, especially in I/O-bound tasks |
| Aspect | Docker | Virtual Machines (VMs) |
| Virtualization Type | Container-based virtualization | Full hardware virtualization |
| Resource Efficiency | Lightweight, shares the host OS kernel | Heavyweight, requires its own OS and more resources |
| Startup Time | Fast, near-instant startup | Slower startup, as a full OS must boot |
| Portability | Highly portable, can run on any system with Docker installed | Less portable, as VMs are tied to specific hypervisors |
| Use Case | Ideal for microservices, CI/CD pipelines, and development environments | Suitable for running different OS environments on the same hardware, legacy application support |
| Aspect | <div> | <span> |
| Display | Block-level | Inline-level |
| Width | Takes up full width | Takes up only the width of its content |
| Usage | Used for grouping large sections of content | Used for styling small portions of text |
| Line Break | Starts on a new line | Does not start on a new line |
| Aspect | PUT | PATCH |
| Purpose | Replaces the entire resource | Updates part of the resource |
| Idempotence | Idempotent, multiple identical requests produce the same result | Not necessarily idempotent |
| Use Case | When you need to update the whole resource | When you need to modify only specific fields |
| Aspect | OAuth | JWT (JSON Web Token) |
| Purpose | Authorization protocol for third-party access | Token format for securely transmitting information |
| Token Structure | Uses access tokens and refresh tokens | Self-contained, stateless tokens with payload, signature |
| Use Case | Best for third-party app access (e.g., social login) | Best for stateless, server-to-client authentication |
Clearing floats is necessary when you want to ensure that elements after a floated element do not wrap around it. This is often needed after using floating elements for layout purposes to prevent issues with layout or overlapping content.
Example:
| Aspect | RESTful API | SOAP API |
| Protocol | Uses HTTP/HTTPS | Uses XML-based protocol over HTTP, SMTP, etc. |
| Flexibility | More flexible, can return data in various formats | Strict, uses XML exclusively |
| Learning Curve | Easier to learn and implement | Steeper learning curve due to complexity |
| Use Case | Best for web services with lightweight communication | Best for enterprise-level, secure communication |
ACID is the abbreviation of Atomicity, Consistency, Isolation and Durability. These four qualities make certain that database transactions take place in a smooth way.
| Aspect | Static Typing | Dynamic Typing |
| Type Checking | Types are checked at compile-time | Types are checked at runtime |
| Error Detection | Errors are caught during the compilation | Errors are caught during the execution |
| Flexibility | Less flexible, but safer | More flexible, but riskier |
| Use Case | Best for large, complex applications where type safety is crucial | Best for smaller projects where flexibility is needed |
An application server refers to a software framework that provides an environment for running web applications. It manages business logic, database connections and client-server communications. Examples include Apache Tomcat, Microsoft IIS and JBoss.
Referential transparency describes the property of functions where their output will always be consistent given the same input without depending on any external state or side effects. This is very important in functional programming as it leads to a more predictable and maintainable code base.
| Aspect | Abstract Class | Interface Class |
| Methods | Can have both abstract and concrete methods | Only abstract methods (in most languages) |
| Multiple Inheritance | Typically supports single inheritance | Supports multiple inheritance |
| Fields | Can have fields with implementation | No fields, only method signatures |
| Use Case | When you need to share common behaviour and implementation | When you need to define a contract without implementation |
A docstring is a string literal used to document a Python module, class, function, or method. It is placed right after the definition and can be accessed using the __doc__ attribute.
Example:
Entity Bean is a type of Enterprise JavaBean (EJB) that represents persistent data stored in a database. Each instance of an Entity Bean corresponds to a row in a database table, and the bean’s state is synchronised with the database.
An Iterator is an object that allows traversal of elements in a collection (like lists or arrays) one at a time. In Python, an iterator must implement the __iter__() and __next__() methods.
Example:
| Aspect | Continuous Integration (CI) | Continuous Deployment (CD) |
| Purpose | Automated testing and integration of code changes | Automates the release of code to production |
| Focus | Ensures code integrates and passes tests | Ensures code is deployed quickly and consistently |
| Manual Intervention | Requires human approval for deployment | Fully automated, no human intervention required |
Dependency injection is a design pattern where an object’s dependencies are provided externally rather than the object creating them itself. This promotes loose coupling and easier testing.
Continuous integration (CI) is a development practice where developers frequently integrate code into a shared repository. Each integration is verified by an automated build and testing process to detect issues early.
The Bootstrap grid system is a layout system that uses a series of containers, rows, and columns to arrange content. It’s based on a 12-column grid, allowing responsive layout designs that adjust across different screen sizes.
| Aspect | XML (eXtensible Markup Language) | JSON (JavaScript Object Notation) |
| Data Structure | Uses a tree structure with nested elements | Uses a key-value pair structure |
| Syntax | More verbose with opening and closing tags | More concise, uses curly braces and arrays |
| Use Case | Best for documents with complex hierarchies | Best for data interchange between systems |
| Readability | Less readable due to verbosity | More readable due to simplicity |
| Parsing | Requires more complex parsers | Easily parsed with built-in functions in most languages |
To add a badge to a list group item in Bootstrap:
Long polling is a technique where the client requests information from the server, and the server holds the request open until new data is available, reducing the need for frequent polling. This helps simulate real-time updates.
Use calc() in Tailwind CSS by applying it directly in your custom CSS or inline styles, as Tailwind does not have a built-in utility for calc():
The Alert component in Bootstrap is used to display important messages to the user. It comes with various contextual styles (e.g., success, danger, warning) and can be dismissible.
| Aspect | HTTP/1.1 | HTTP/2 |
| Connection | Opens a new connection for each request | Uses a single connection for multiple requests (multiplexing) |
| Speed | Slower due to connection overhead | Faster due to multiplexing and header compression |
| Header Compression | Headers are not compressed | Uses HPACK header compression |
| Priority | No request prioritisation | Allows prioritisation of requests |
| Use Case | Still widely used but less efficient for modern web | Preferred for high-performance web applications |
The ‘this’ keyword in JavaScript refers to the object from which the function was called. Its value depends on the context in which it is used (e.g., global, object, or function context).
Example:
Callback hell refers to the situation where multiple nested callbacks make the code hard to read and maintain. This often occurs in asynchronous programming when each callback depends on the previous one, leading to deeply nested structures. Using promises or async/await can help mitigate this issue.
| Aspect | Encryption | Hashing |
| Purpose | Converts data into a secure format for transmission | Converts data into a fixed-size hash value |
| Reversibility | Reversible with the correct key | Irreversible, designed to be a one-way function |
| Use Case | Protects data in transit or at rest | Verifies data integrity, stores passwords |
| Algorithms | AES, RSA | MD5, SHA-256 |
| Security | Depends on key strength | Vulnerable if weak hash algorithms are used |
Preparing for a full-stack developer interview requires a solid understanding of both front-end and back-end technologies. By mastering the key concepts, tools, and techniques discussed in this blog, you’ll be well-equipped to answer even the most challenging questions. From understanding the nuances of various programming languages to knowing the intricacies of web development frameworks, being prepared will set you apart from other candidates.
As you continue your journey in full-stack development, remember that the industry is always evolving. Staying up-to-date with the latest trends and continuously practising your skills will not only help you in interviews but also in your overall career growth. Keep learning, stay curious, and embrace the challenges ahead.
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