Video summary

Infosys Real Interview For Experienced Candidate

Main summary

Key takeaways

Technology

Key technical concepts & features discussed

Microservices (and comparison to monoliths)

  • Definition/meaning: Microservices are independent services that can be:

    • Deployed independently
    • Scaled independently
    • Developed independently

  • Monolith vs microservices scaling/deployment:

    • With monolithic services, the whole application must be scaled together.
    • With microservices, only the required service(s) can be scaled and deployed.

API Gateway request routing

  • Incoming requests go to an API Gateway.
  • The gateway uses port/IP information to forward requests to the correct microservice.

Microservice reliability & observability patterns

  • Circuit breaker pattern: Used when one microservice calls another and the called service fails; it returns an appropriate response.
  • Distributed tracing: Used to trace a request across multiple microservices (i.e., follow request flow across services).

REST APIs / Spring Boot (web service concepts)

RESTful endpoints & HTTP methods (as asked)

Mentioned/used in Spring Boot with mappings such as:

  • GET (retrieve data)
  • POST (create/save data)
  • PUT (intended as “save/update data”)
  • PATCH (partial update)
  • DELETE (delete)

Status codes discussed:

  • 200 (“OK”)
  • 404 (“page not found”)
  • 500 (“internal server error”)
  • 401 was mentioned, but other success codes (e.g., 201/204) were not clearly recalled.

Spring Boot layer flow (request → response)

Client request (e.g., Postman) goes through:

  • Dispatcher Servlet / Front controller
  • Controller
  • Service layer (business logic)
  • View resolver & View (described as part of the flow; implies MVC-style handling)

Follow-up asked about common layer names:

  • Controller layer
  • Service layer
  • Repository / Persistence layer (mapped to persistence concept)

Spring Boot project configuration

  • Maven dependencies:
    • Dependencies are added in pom.xml.
    • They are stored in an internal Maven repository/cache location (a local user location was mentioned, but the exact path wasn’t clearly detailed).

Java access specifiers

Covered:

  • private
  • protected
  • public
  • default/package-private

With basic intended visibility:

  • class-only
  • subclass-only
  • any
  • same package

Client/server flow exercise (algorithm sketch)

The candidate gave a structured flow example:

  • POST mapping to save data to the database
  • GET mapping to retrieve data by path variable (e.g., studentId)

Example architecture in the sketch:

  • Controller receives request body/params
  • Service processes and calls
  • Repository (DAO/persistence layer) for persistence methods like:
    • save(...)
    • findAll(...) / retrieval methods (mentioned generally)

Docker concepts & commands

  • Docker described as a containerized platform.

Dockerfile components (conceptually)

  • FROM (base image, e.g., Java)
  • Working directory (WORKDIR)
  • Optional metadata (LABEL)
  • Execution command via ENTRYPOINT

Docker lifecycle commands

  • Docker build (build image from Dockerfile)
  • Docker run (run container from image)
  • Docker stop (stop container)
  • Docker push (push image to Docker Hub/repository)

Commands for inspection

  • Docker images (list images)
  • Docker ps (list running containers)

Hosting / running Spring Boot microservices locally

  • Hosting/run explained as:
    • Configure port/IP in application properties
    • Start Spring Boot application; it runs on the configured port

Mentioned:

  • Default Tomcat support
  • A confusing statement about “default port is 80” (though typical Spring Boot defaults are often 8080 unless changed)

Reviews / guides / tutorials

  • No formal “review” of products/tools; the video functions mainly as a mock interview / technical Q&A.
  • Includes a mini tutorial-style request flow walkthrough for REST:
    • POST (save) and GET (fetch) across Controller → Service → Repository.

Main speakers / sources

  • Interviewer: Jack
  • Interviewee (candidate): S (appears as “Sh Jack…;” full name not captured)

Original video