NestJS Developer Interview Questions & Video Screening

Introduction

Hiring the right NestJS Developer is critical for building scalable, maintainable server-side applications in the Information Technology (IT) industry. A good hire reduces technical debt and accelerates delivery of APIs and backend services.

This guide provides role-specific NestJS Developer interview questions at basic, intermediate, and advanced levels, plus five pre-screening one-way video interview questions ideal for ScreeningHive. Use these to standardize screening and speed hiring decisions.

NestJS Developer Interview Questions

Basic NestJS Developer Interview Questions

• What is NestJS and how does it differ from Express or plain Node.js?
• Explain the role of controllers and providers in a NestJS application.
• What are modules in NestJS and why are they important?
• How do decorators work in NestJS and give an example of a common decorator?
• Describe how dependency injection is implemented in NestJS.
• What is the purpose of Pipes in NestJS and when would you use them?
• How does NestJS handle middleware and where is middleware applied?
• What are Guards in NestJS and how do they relate to authentication and authorization?

Intermediate NestJS Developer Interview Questions

• Describe how you would structure a NestJS project for a team working on multiple microservices.
• Explain how to implement user authentication using JWT in NestJS including token issuance and verification.
• How would you create and use custom decorators to extract request metadata from an incoming request?
• Describe a strategy to validate and transform incoming request payloads with class-validator and Pipes.
• How would you implement role-based access control in a NestJS application?
• Explain how to integrate TypeORM with NestJS and handle database migrations in production.
• How can you implement caching for REST endpoints in NestJS and what cache store would you choose?
• Describe how to create a versioned API in NestJS and manage backward compatibility.
• Explain error handling in NestJS and how to create custom exception filters for consistent API responses.
• How would you instrument a NestJS app for distributed tracing and performance monitoring?

Advanced NestJS Developer Interview Questions

• Design an architecture for scalable microservices using NestJS. Include communication patterns and service discovery approach.
• How would you optimize NestJS application startup time and reduce memory footprint for serverless deployment?
• Discuss strategies for handling database migrations and zero downtime deploys in a NestJS production environment.
• Explain advanced security measures you would implement for a NestJS API handling sensitive data.
• How do you approach designing a GraphQL API with NestJS, including schema design and resolver performance optimization?
• Describe techniques to profile and optimize slow endpoints in NestJS, including instrumenting code and database query tuning.
• How would you implement multi-tenant support in NestJS while ensuring data isolation and performance?
• Explain how to build a plugin or shared library of NestJS modules that can be versioned and consumed by multiple teams.
• Describe an approach to migrate a large monolithic NestJS application into microservices with minimal disruption.
• How do you lead architectural reviews and code standards for a team building multiple NestJS services to ensure consistency and quality?

Pre-Screening Video Interview Questions for NestJS Developer

These five one-way video interview questions are ideal for ScreeningHive to quickly assess candidate communication, problem approach, and practical experience before scheduling live interviews.

1. Describe a recent NestJS project you worked on and your primary responsibilities.

   This evaluates practical experience, project ownership, and the candidate's ability to communicate technical contributions clearly.

2. Explain how you implemented authentication and authorization in one of your NestJS applications.

   This checks understanding of security patterns, JWT or OAuth usage, and how the candidate enforces access control.

3. Give an example of a challenging bug or performance issue you diagnosed in a NestJS service and how you resolved it.

   This reveals debugging skills, use of logging and profiling tools, and problem solving under real conditions.

4. How do you structure error handling and API responses to ensure consistency across services?

   This evaluates design thinking around user-friendly error messages, exception filters, and API standards.

5. Describe your approach to testing NestJS applications, including unit and integration tests.

   This assesses familiarity with testing frameworks, test isolation, and strategies to maintain reliable CI pipelines.

Conclusion

Using structured NestJS Developer interview questions helps hiring teams and recruiters evaluate technical skills, architectural thinking, and team fit. Candidates benefit by understanding expectations and preparing focused responses.

ScreeningHive one-way video interviews enable faster screening, consistent evaluations, and better candidate experience. Incorporating these questions into your pre-screening process will streamline hiring and improve decision quality.