Developer Interview Tips – Comprehensive Guide

This compilation is ideal for software developers preparing for interviews, assessments, or technical exams. It covers DevOps, databases, frontend/backend frameworks, testing, microservices, programming principles, and more.

🔧 DevOps & CI/CD

1. Tools for CI/CD (Continuous Integration/Continuous Deployment):

   • Jenkins

   • GitLab CI/CD

   • CircleCI

   • Travis CI

   • GitHub Actions

   • Azure DevOps Pipelines
     These tools automate code building, testing, and deployment processes.

2. Monitoring Tools for Performance Checking:

   • Prometheus + Grafana

   • New Relic

   • Datadog

   • Nagios

   • ELK Stack (Elasticsearch, Logstash, Kibana)

3. Configuration in Microservices:

   • Use centralized config servers (e.g., Spring Cloud Config, Consul)

   • Load config per environment (Dev, QA, Prod)

   • Secrets management (e.g., Vault)

4. How to Reduce Load in Microservices:

   • Use load balancers

   • Implement caching (Redis, Memcached)

   • Apply circuit breakers (e.g., Hystrix)

   • Queue-based communication (Kafka, RabbitMQ)

5. Function of an API Gateway in Microservices:

   • Acts as a single entry point

   • Handles authentication, logging, rate limiting, API versioning

   • Examples: Kong, API Gateway (AWS), Zuul, NGINX

🧱 Architecture and Frameworks

6. Kubernetes (K8s) in Microservice Architecture:

   • Automates deployment, scaling, and management of containerized applications

   • Key for orchestrating microservices

7. Server-Side Rendering (SSR) Frameworks:

   • Next.js (React)

   • Nuxt.js (Vue.js)

   • NestJS (Node.js) – For server-side API logic

8. State Management in JavaScript:

   • Tools: Redux, MobX, Zustand, Vuex

   • Helps manage shared application state predictably

🧪 Testing

9. Test-Driven Development (TDD):

   • Write tests before writing functional code

   • Follows Red-Green-Refactor cycle

10. Unit Testing:

• Tests individual functions or modules in isolation

• Tools: Jest, Mocha, PyTest, JUnit

11. Integration Testing:

• Tests interaction between components or services

• Ensures that combined modules work together as expected

12. Tools for Testing RESTful APIs:

• Postman

• Swagger (OpenAPI)

• Insomnia

• JUnit (Java)

• Pytest + requests (Python)

🌐 REST, GraphQL & API Essentials

13. What is REST?

• Representational State Transfer

• An architectural style for designing scalable APIs using HTTP verbs: GET, POST, PUT, DELETE.

14. REST vs. GraphQL:
    | Feature | REST | GraphQL |
    |----------------|-------------------|-------------------|
    | Data Fetching | Multiple endpoints| Single endpoint |
    | Overfetching | Possible | Avoided |
    | Flexibility | Fixed response | Client-defined queries |

15. API Versioning:

• Helps manage breaking changes

• Approaches: URI versioning (/v1/users), Header versioning, Media Type versioning

16. Query Parameters in APIs:

• Allow clients to pass optional information (e.g., /users?sort=asc&limit=10)

• Used for filtering, sorting, and pagination

💻 Frontend Essentials

17. Angular Key Features:

• Two-way data binding

• Dependency Injection

• Routing module

• Component-based architecture

• RxJS for reactive programming

18. Single Page Application (SPA):

• Loads a single HTML page and dynamically updates the content

• Uses AJAX for server communication

• Frameworks: Angular, React, Vue.js

19. CSS Box Shadow:

• Adds shadow effects to elements

20. To Increase Space Between Border and Content:

• Use padding property in CSS

21. CSS Attribute Selector (Correct):

🗃️ Database Concepts

22. SQL vs NoSQL:

• SQL: Structured, relational (PostgreSQL, MySQL)

• NoSQL: Unstructured or semi-structured (MongoDB, Cassandra)

23. Indexes in Databases:

• Speed up data retrieval

• Created on columns frequently used in WHERE clauses

24. Database Views:

• Virtual tables based on result of a query

• Useful for abstraction, filtering, and security

25. Self-Referencing Table:

• A foreign key refers to the same table

• E.g., employee-manager relationships

26. Splitting One Table into Multiple:

• This is done using Normalization to avoid redundancy

• Often results in One-to-Many or Many-to-One relationships

27. Can a Table Have Multiple Primary Keys?

• No, but a composite primary key (using multiple columns) is allowed

• Multiple foreign keys are allowed

🧠 Programming Concepts & Logic

28. Object-Oriented Programming (OOP) Features:

• Encapsulation, Inheritance, Polymorphism, Abstraction

29. Encapsulation:

• Wrapping data and methods in a single unit (class)

• Controls access via access modifiers (private, public)

30. Single Responsibility Principle:

• A class should have only one reason to change (only one responsibility)

31. Function Truths:

• Functions can return other functions

• Closures can access outer scope variables

32. Recursion:

• Function that calls itself

• Requires a base case to avoid infinite loops

33. Output of console.log(this) in Global Scope:

• In browsers: Logs the window object

• In strict mode or modules: undefined

34. Output of 10 + 20 + "30":

• 30 + "30" = "3030"
  Answer: "3030"

35. Try-Catch-Finally Concept:

• Try: Contains code that might throw an error

• Catch: Handles the error

• Finally: Executes always, regardless of try/catch outcome

36. Modularity (Qn 34 concept):

• Design principle to split programs into independent, reusable modules

• Improves maintainability, scalability, and readability

💡 Miscellaneous

37. Difference Between Upgrade vs Update:

• Update: Minor change (e.g., security patch)

• Upgrade: Major version change with new features

38. Real-Time Collaboration Design Tool:
    Correct Answer: a) Figma

• Others: Adobe XD, InVision, Sketch (not real-time collaboration)

39. Write Once, Run Anywhere (WORA) Frameworks:

• React Native

• Flutter

• Ionic

• Xamarin
  These allow cross-platform mobile app development

40. How to Decrease Loop Workload:

• Reduce iterations using better logic

• Use array methods (map, filter)

• Cache calculations

• Use async/parallel processing where possible