| 1 | What is Domain-Driven Design (DDD), and how do its concepts of entities, value objects, and aggregates apply to a Node.js codebase? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Advanced |
| 2 | What is a layered (n-tier) architecture in a Node.js/Express application, and what are its typical layers? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Advanced |
| 3 | What is a Hexagonal Architecture (Ports and Adapters), and what specific benefit does it provide for a Node.js API? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Advanced |
| 4 | How is the Factory pattern commonly applied in Node.js applications, and what problem does it solve? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Intermediate |
| 5 | What is the Singleton pattern, and what are the specific risks of using it in a Node.js application? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Intermediate |
| 6 | What is Dependency Injection, and how is it typically implemented in Node.js given the language has no built-in DI container? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Intermediate |
| 7 | What is the Strategy pattern, and how would you apply it to support multiple payment providers in a Node.js checkout service? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Intermediate |
| 8 | What is a Facade pattern, and how might it be used to simplify a Node.js application's interaction with several third-party SDKs? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Advanced |
| 9 | What is the Saga pattern, and how does it manage distributed transactions across multiple Node.js microservices? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Advanced |
| 10 | What is the Module pattern in Node.js, and how does it enable encapsulation? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Intermediate |
| 11 | What is the Middleware (Chain of Responsibility) pattern as implemented by Express, and how does the 'next()' function drive it? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Intermediate |
| 12 | What is the Repository pattern, and how does it help decouple business logic from a specific database technology? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Advanced |
| 13 | What is the Observer pattern, and how does Node.js's EventEmitter class implement it natively? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Advanced |
| 14 | What is a Circuit Breaker pattern, and why is it important when a Node.js service calls an unreliable downstream dependency? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Advanced |
| 15 | What is the CQRS (Command Query Responsibility Segregation) pattern, and when is it appropriate to introduce in a Node.js system? Node.js › Architecture & Design Patterns | Node.js | Architecture & Design Patterns | Advanced |
| 16 | How should a large, complex PHP application evolve its architecture beyond basic MVC to maintain organization and testability as the codebase and team grow significantly? PHP › MVC Architecture in PHP | PHP | MVC Architecture in PHP | Advanced |
| 17 | How should a large scale application design its file upload architecture to handle high volumes of uploads reliably, including virus scanning and offloading storage to a dedicated service? PHP › File Upload Handling | PHP | File Upload Handling | Advanced |
| 18 | What are the key benefits and tradeoffs of splitting a Node.js monolith into microservices? Node.js › Microservices Architecture with Node.js | Node.js | Microservices Architecture with Node.js | Intermediate |
| 19 | What is an API Gateway, and what role does it play in front of a collection of Node.js microservices? Node.js › Microservices Architecture with Node.js | Node.js | Microservices Architecture with Node.js | Intermediate |
| 20 | How does distributed data ownership work in microservices -- specifically, why shouldn't multiple services share direct access to the same database? Node.js › Microservices Architecture with Node.js | Node.js | Microservices Architecture with Node.js | Advanced |
| 21 | What is the role of a Controller in the MVC pattern, and what responsibilities should typically be kept out of a controller to maintain good separation of concerns? PHP › MVC Architecture in PHP | PHP | MVC Architecture in PHP | Beginner |
| 22 | How do Models in MVC represent both data structure and business logic, and how does this differ from a Model being purely a simple database representation? PHP › MVC Architecture in PHP | PHP | MVC Architecture in PHP | Intermediate |
| 23 | How would you design a multi-channel notification system in Node.js that can send the same logical notification via email, SMS, or push depending on user preference? Node.js › Email & Notifications | Node.js | Email & Notifications | Advanced |
| 24 | How does Kafka's architecture (topics, partitions, consumer groups) differ fundamentally from RabbitMQ's queue-based model? Node.js › Message Queues (RabbitMQ & Kafka) | Node.js | Message Queues (RabbitMQ & Kafka) | Advanced |
| 25 | How does the concept of a Service Layer complement traditional MVC by providing an additional place for complex business logic that spans multiple models? PHP › MVC Architecture in PHP | PHP | MVC Architecture in PHP | Advanced |
| 26 | How would you design configuration for a multi-tenant application where each tenant needs different settings resolved at runtime? .NET › Configuration & Options | .NET | Configuration & Options | Advanced |
| 27 | How can PHP's interface based type hinting combined with abstract classes support building a genuinely extensible plugin architecture within an application? PHP › Interfaces & Abstract Classes | PHP | Interfaces & Abstract Classes | Advanced |
| 28 | What is the difference between a relational (SQL) database and a NoSQL database, and how does this affect a Node.js application's data layer? Node.js › Databases | Node.js | Databases | Beginner |
| 29 | Why should an application typically avoid storing uploaded files directly on the same server instance that runs the web application? Node.js › File Uploads & Media Processing | Node.js | File Uploads & Media Processing | Beginner |
| 30 | What is a feature flag, and how would you implement one in a Node.js application to control a new feature's rollout? Node.js › Cloud & DevOps | Node.js | Cloud & DevOps | Intermediate |
| 31 | What is middleware in Express, and what is the significance of the order in which middleware is registered? Node.js › Express & Middleware | Node.js | Express & Middleware | Intermediate |
| 32 | What is the difference between application-level, router-level, and route-specific middleware in Express? Node.js › Express & Middleware | Node.js | Express & Middleware | Intermediate |
| 33 | What is the purpose of GraphQL fragments, and how do they help avoid duplicating field selections across multiple queries? Node.js › GraphQL | Node.js | GraphQL | Intermediate |
| 34 | What is a database migration, and how do tools like Sequelize's migration system or a standalone tool like Knex help manage schema changes over time? Node.js › Databases & ORMs (MongoDB/Mongoose, SQL/Sequelize) | Node.js | Databases & ORMs (MongoDB/Mongoose, SQL/Sequelize) | Intermediate |
| 35 | How would you structure application configuration to support multiple environments (development, staging, production) cleanly? Node.js › Environment Variables & Configuration | Node.js | Environment Variables & Configuration | Intermediate |
| 36 | How do GraphQL Mutations differ from Queries, and how would you define one to create a new resource? Node.js › GraphQL with Node.js | Node.js | GraphQL with Node.js | Intermediate |
| 37 | When would you choose a message queue/broker (RabbitMQ or Kafka) over simply making direct HTTP calls between Node.js microservices? Node.js › Message Queues (RabbitMQ & Kafka) | Node.js | Message Queues (RabbitMQ & Kafka) | Intermediate |
| 38 | What is the difference between vertical and horizontal performance optimization strategies for a Node.js application, and how do you decide which to pursue first? Node.js › Performance Optimization & Profiling | Node.js | Performance Optimization & Profiling | Intermediate |
| 39 | How do you organize namespaces effectively in a larger application to reflect logical groupings such as models, services, and controllers? PHP › Namespaces & Autoloading | PHP | Namespaces & Autoloading | Intermediate |
| 40 | What is database replication, and how does a Node.js application typically route reads to replicas while sending writes to a primary? Node.js › Databases | Node.js | Databases | Advanced |
| 41 | What is database sharding, and what problem does it solve that replication alone doesn't address? Node.js › Databases | Node.js | Databases | Advanced |
| 42 | What is a database deadlock, and how might it occur between two concurrent transactions in a Node.js application? Node.js › Databases | Node.js | Databases | Advanced |
| 43 | How would you structure a large Express application using the Router to organize routes into feature-based or resource-based modules? Node.js › Express & Middleware | Node.js | Express & Middleware | Advanced |
| 44 | How would you implement GraphQL schema stitching or federation to compose a single unified GraphQL API from multiple underlying microservices? Node.js › GraphQL | Node.js | GraphQL | Advanced |
| 45 | What is the N+1 query problem in the context of an ORM like Mongoose or Sequelize, and how do you avoid it? Node.js › Databases & ORMs (MongoDB/Mongoose, SQL/Sequelize) | Node.js | Databases & ORMs (MongoDB/Mongoose, SQL/Sequelize) | Advanced |
| 46 | How would you implement a custom event that carries multiple pieces of data, and what's the convention for structuring the emitted payload? Node.js › Events & EventEmitter | Node.js | Events & EventEmitter | Advanced |
| 47 | How would you implement distributed tracing across multiple Node.js microservices using OpenTelemetry? Node.js › Logging & Monitoring | Node.js | Logging & Monitoring | Advanced |