Full Stack Developer Interview Questions

1.1The full stack developer role - owning features end to end and the skills required

1.2Web architecture fundamentals - client-server model, HTTP, browsers, and how a web request flows

1.3The modern web stack - frontend frameworks, backend runtimes, databases, and deployment infrastructure

1.4Choosing the right tool - how full stack developers make technology decisions for different problems

2.1JavaScript fundamentals - event loop, closures, promises, async/await, and the language mechanics that matter

2.2Frontend frameworks - component model, state management, hooks, and building performant UIs

2.3CSS and layout - flexbox, grid, responsive design, and making interfaces that work across devices

2.4Frontend performance - bundle size, lazy loading, Core Web Vitals, and optimising the user experience

3.1RESTful API design - resources, methods, status codes, versioning, and building APIs others want to use

3.2Authentication and authorisation - sessions, JWT, OAuth 2.0, and implementing security correctly

3.3Server-side architecture - MVC, service layer, dependency injection, and organising backend code maintainably

3.4Background jobs, queues, and async processing - how to handle work that should not block an HTTP response

4.1Relational database design for full stack developers - schemas, migrations, and working with SQL confidently

4.2ORMs - how they work, when they are useful, and when to go around them

4.3NoSQL for full stack - when to use document stores, key-value stores, and the trade-offs vs relational

4.4Database performance - query optimisation, indexing, and diagnosing slow queries in a full stack application

5.1Integrating third-party APIs - authentication, rate limiting, error handling, and designing for failure

5.2Payment integration - the concepts, PCI compliance scope, and the developer responsibilities

5.3Email, SMS, and notification services - integration patterns and managing deliverability

5.4Webhooks - receiving, validating, and processing real-time events from external systems

6.1Testing strategy for full stack - what to test at each layer and the right balance between test types

6.2Backend unit and integration testing - testing business logic, database interactions, and API behaviour

6.3Frontend testing - component tests, user interaction tests, and testing what the user actually sees

6.4End-to-end testing - testing the full application flow and managing the brittleness of e2e tests

7.1CI/CD for full stack developers - automated testing, build pipelines, and deployment workflows

7.2Containerisation - Docker for development consistency and production deployment

7.3Cloud deployment - deploying full stack applications to managed platforms and cloud infrastructure

7.4Environment management - development, staging, and production environments and managing differences between them

8.1OWASP Top 10 in a full stack context - XSS, CSRF, SQL injection, and preventing them in your own code

8.2Secure authentication - password storage, MFA implementation, and common authentication mistakes

8.3Input validation and output encoding - the defences every full stack developer must implement

8.4Dependency security - managing third-party package vulnerabilities and keeping dependencies current

9.1Monolith vs microservices - the trade-offs and what is right for different stages of a product

9.2API gateway and BFF patterns - structuring the backend for different client types

9.3Caching strategies - client-side, server-side, and CDN caching for full stack applications

9.4Designing for scale - how to architect a full stack application that can grow without a rewrite

10.1Technical questions - JavaScript, frontend frameworks, APIs, databases, and security specific to full stack

10.2Coding exercises - building a small feature end to end under interview conditions

10.3System design questions - designing a full stack application for a given set of requirements

10.4Salary negotiation for full stack roles, evaluating a tech stack and team quality, and questions that reveal what working there is really like