Top Interview Questions/Answers When Hiring Node.js Developers?
How do you ensure to develop secure Node.js applications?
Developing a secure Node.js application involves following practices such as input validation and sanitization leveraging ORM(object relational mapping) to prevent SQL injection attacks. Authorization mechanisms such as secure session management, securing secrets via vaults, and implementation of practices to reduce future vulnerabilities.
What is the reason behind Node.js being single threaded?
Node.js is based on a single threaded model because it follows an event-driven, non-blocking I/O model that handles all incoming requests and events using one main thread. This allows Node.js to efficiently manage connections and asynchronous I/O operations without overhead of thread creation and context switching.
What are streams in Node.js and what is their significance?
Streams leverage Node.js developers to read and manipulate data in continuous data flows rather than loading it entirely into memory. They are very useful when working with larger files or network communication with enhanced performance and memory efficiency.
How Are Applications Optimized When You Hire Node.js Developers?
Improving data queries and indexing
Node.js developers integrate quality database optimization techniques such as designing efficient schemas, creating indexes and integrating caching mechanisms for frequently accessed data.
Minimizing blocking operations
To optimize Node.js applications, it is crucial the developer you hire must have knowledge on operations that can cause blocking or serve as a roadblock to the performance. Asynchronous patterns such as callbacks or async/await need to be employed for the app to continue executing other tasks while waiting for operations to be completed.
Connection pooling
When you hire Node.js developers, they must be well-versed with establishing connection pooling which involves reusing and managing database connections efficiently. This can be done utilizing connection pooling supported implementations for SQL/NoSQL databases.
What Are The Key Technical Skills Needed When You Hire Node.js Developers?
Familiarity with popular web applications frameworks
When you hire Node.js developers, it is crucial they hold familiarity with web application frameworks such as Express.js, Koa.js or Nest.js. Each developer must know how to work well with these frameworks to build scalable and maintainable web applications.
RESTful APIs Integration
Node.js developers for hire must have knowledge of HTTP(s) protocols, status codes and implementation strategy for integration efficient API endpoints. Integration of API’s must ensure following authentication mechanisms such as API keys or JWT token specified by the API documentation.
Understanding on programming languages
The Node.js developer you hire should have immense knowledge on multiple programming languages. Deep expertise in the asynchronous programming, features, syntax, design patterns needed on JavaScript, which is the core language of Node.js. Additionally, understanding of web development languages such as HTML and CSS is significant.
Knowledge on database
Node.js developers must have knowledge on integrating databases such as MongoDB, MySQL, PostgreSQL or Redis. This is because the database plays an integral role in application by providing storage for data.
Key Database Languages/Command In Node.js
SQL (Structured Query Language)
SQL leverages developers to retrieve, update, create and delete data by interacting with relational databases such as MySQL, PostgreSQL, Microsoft SQL Server etc. The Node.js libraries including Knex.js and Sequelize provide convenient methods for building SQL queries while offering object relational mapping (ORM) capabilities to simplify database interactions.
Redis Commands
Redis itself is not a language, but rather an in-memory database system with its own command-based interface. Its own set of commands allows Node.js developers to store, retrieve, cache and manipulate data.
NoSQL Query Language
Databases such as MongoDB CouchDB utilize query language specific to the structure of the databases. The query language for MongoDB is based on JavaScript enabling developers to perform CRUD operations such as sorting, filtering and aggregation.
Vast Ecosystem Of Node.js Libraries
Mongoose
An object document mapping(OBM) library leveraging easy access to MongoDB databases. It supports Query building, validation schema-based modeling.
Socket.io
Socket.io is a flexible Node.js library enhancing real-time communication between server and client. Utilizing this library, developers get to integrate features such as real-time chat, collaborative capabilities and server-side push mechanism.
Lodash
Lodash is a utility library which provides functionalities manipulating arrays, objects and strings. Functional programming, data manipulation, and iteration are among the useful methods offered by the program.
Sequelize
This ORM library holds multi-support capabilities for database systems including MySQL, PostgreSQL and Microsoft SQL Server. Leveraging Sequelize, developers get it to integrate API by defining models, executing queries and handling database operations.
