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Codementor Office Hours  ›  Live Mock Technical Interview - ReactJS and JavaScript

Live Mock Technical Interview - ReactJS and JavaScript

 With  Matt Oates
  Wed, Nov 2, 11:00 AM (PST)
Video & Recap
Live Mock Technical Interview - ReactJS and JavaScript

Are you looking to land a job as a front-end developer? An experienced interviewer conducted a live mock technical interview with a candidate looking for a front-end developer job.

Every company has a different interview process, so this mock interview focused on aspects of the technical interview that are common across companies and industries. It included algorithm questions, coding exercises, feedback, and audience Q&A.

Book a mock technical interview with Matt here.

Video timeline:
0:00 Introductions
3:50 Coding exercise
41:00 Technical questions
50:00 Feedback and Q&A

Notes from the interviewer

Coding exercise - https://jsfiddle.net/ssgyre4v/
Implement up and down arrows using the reducer on line 24. The up arrow should move the todo up one spot in the array, and the down arrow should do the opposite.

Key points from technical questions:

  • Redux reducers cannot modify state that's passed in
  • Why use redux over alternatives? (flux, mobx)
    A: Redux is a functional pattern, which makes your application more predictable. This also lends itself well to automated testing.
  • What are some problems with the redux architecture?
    A: A naive implementation of a form input can be tricky. Multiple instances of an input if linked to the same data, would obviously have and show the same data. http://redux-form.com/6.1.1/ is one solution around that. Boilerplate also in some cases.
  • Immutable data structures are not provided natively by JavaScript. (Object.freeze only freezes the top level object)
  • Redux dev tools:
    Redux dev tools implements the Event Sourcing pattern. Big points with interviewers if you can work that into an interview appropriately. React and Redux are great tools, but they will never outlast paradigms like the Event Sourcing pattern.
  • What can be gained by applying the Event Sourcing pattern to a backend service?
  • What have you worked on that you're most proud of? (Always be prepared to answer this in an interview.)

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Codementor Expert
Matt Oates
Matt Oates

As a silicon valley engineer, I've worked on enterprise-scale sites such as Facebook, cultivated Clover's suite of 1st party web applications from scratch, hacked on WebVR, and founded the modern web application boardom.io, I've acquired a deep...

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