josethz00

Senior Frontend Interview Questions

Some questions about frontend development that might be in your next job interview. The questions were formulated by @mauvieira, a super senior fullstack developer

General Frontend

• What are the strategies we can use to optimize the performance of web applications?

  • CDNs, GraphQL (maybe) to reduce overfetching, improve backend performance, use SSR and/or SSG, lazy loading for loading assets only when it's needed, minimize and compress HTML, CSS and JS files, and optimize images by compressing and resizing them.

• What are Web Vitals (LCP, FID, CLS)? And how are they applied in the real world?

getify

What Hiring Should Look Like

This is definitely not the first time I've written about this topic, but I haven't written formally about it in quite awhile. So I want to revisit why I think technical-position interviewing is so poorly designed, and lay out what I think would be a better process.

I'm just one guy, with a bunch of strong opinions and a bunch of flaws. So take these suggestions with a grain of salt. I'm sure there's a lot of talented, passionate folks with other thoughts, and some are probably a lot more interesting and useful than my own.

But at the same time, I hope you'll set aside the assumptions and status quo of how interviewing is always done. Just because you were hired a certain way, and even if you liked it, doesn't mean that it's a good interview process to repeat.

If you're happy with the way technical interviewing currently works at your company, fine. Just stop, don't read any further. I'm not going to spend any effort trying to convince you otherwise.

Andrey2G

ffmpeg -i "c:/videos/sample.mp4
-map 0:v:0 -map 0:a:0 -map 0:v:0 -map 0:a:0 -map 0:v:0 -map 0:a:0
-c:v libx264 -crf 22 -c:a aac -ar 48000
-filter:v:0 scale=w=480:h=360  -maxrate:v:0 600k -b:a:0 64k 
-filter:v:1 scale=w=640:h=480  -maxrate:v:1 900k -b:a:1 128k 
-filter:v:2 scale=w=1280:h=720 -maxrate:v:2 900k -b:a:2 128k 
-var_stream_map "v:0,a:0,name:360p v:1,a:1,name:480p v:2,a:2,name:720p"
-preset slow -hls_list_size 0 -threads 0 -f hls -hls_playlist_type event -hls_time 3
-hls_flags independent_segments -master_pl_name "name-pl.m3u8"
"c:/videos/encoded/name-%v.m3u8"                    

paulfranco

Interview Questions

Node.js

Q1: What do you mean by Asynchronous API? ☆☆

Answer: All APIs of Node.js library are aynchronous that is non-blocking. It essentially means a Node.js based server never waits for a API to return data. Server moves to next API after calling it and a notification mechanism of Events of Node.js helps server to get response from the previous API call.

Source: tutorialspoint.com

bradtraversy

Node.js Deployment

Steps to deploy a Node.js app to DigitalOcean using PM2, NGINX as a reverse proxy and an SSL from LetsEncrypt

1. Sign up for Digital Ocean

If you use the referal link below, you get $10 free (1 or 2 months) https://m.do.co/c/5424d440c63a

2. Create a droplet and log in via ssh

I will be using the root user, but would suggest creating a new user

Stanback

const net = require('net');

//
// A Node.js port of this original Gist: https://gist.github.com/danielfaust/998441
// To find hosts on the network: nmap -Pn -p55000 192.168.12.1/24
//
// Note: This is for Samsung TVs circa 2012-2015 that use a service running on port 55000
//       Samsung TV's circa 2016 and later use a WebSocket service on port 8001 which is different
//

amantheroot

// EXAMINE THE DOCUMENT OBJECT //

// console.dir(document);
// console.log(document.domain);
// console.log(document.URL);
// console.log(document.title);
// //document.title =  123;
// console.log(document.doctype);
// console.log(document.head);
// console.log(document.body);

alexrqs

// The events are from https://www.w3.org/TR/html5/semantics-embedded-content.html#media-elements-event-summary
import videojs from 'video.js'

const Plugin = videojs.getPlugin('plugin')
const EVENTS = [
  'loadstart',
  'progress',
  'suspend',
  'abort',
  'error',

oilsinwater

[TOC]

Caching files Service Workers

@(js study notes)[js|dev|web]

##What is Cache API?

While this API was intended for service workers, it is actually exposed on the window so it can be accessed from anywhere in your script. The entry point is caches.

• ** Used to store assets that have a URL

everget

JavaScript Bitwise Hacks

It assumes the highest positive signed 32-bit float value for numbers. In other words, 2147483647 (or 0x7FFFFFFF or 2^31-1).

Table of Contents

1. Toggle switch
2. Variable swap
3. Math.pow
4. Determine if an integer is a power of 2
5. Round up to the next highest power of 2