rafaeljesus

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    return document.querySelectorAll('button.is-following') || [];
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rafaeljesus

Updated, easy to remember numbers for back-of-the-envelope calculations in system design interviews

Powers of two table

Power    Approx Value (Bytes)       Bytes
-----------------------------------------
10                 1 thousand        1 KB
16                16 thousand       64 KB
20                  1 million        1 MB
30 1 billion 1 GB

rafaeljesus

Why gRPC load balancing is so tricky?

At a high-level, we need to understand two points:

• gRPC is built on HTTP/2, and HTTP/2 is designed to have a single long-lived TCP connection (a sticky and persistent connection);
• To do gRPC load balancing, we need to shift from connection balancing to request balancing;

Some interesting articles about this subject

• Load Balancing gRPC services

rafaeljesus

package facebook;

import java.util.HashSet;
import java.util.Set;

/**
 * The complexity of that algorithm is O(n^m), where:
 *  n - the length of a string.
 *  m - number of permutations.
 */

rafaeljesus

package main

import (
	"bufio"
	"flag"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"regexp"

rafaeljesus

Quick cheat sheet of helpful tmux commands

1. tmux new - Create and attach to a new session.
2. tmux new -s NAME_HERE - Create and attach to a new session named NAME_HERE.
3. CTRL-b, d - Detach (i.e. exit) from the currently-opened tmux session (alternatively, tmux detach). Note, this means press and hold CTRL, press b, release both, press d.
4. tmux ls - Show list of tmux sessions.
5. tmux a - Attach to the previously-opened tmux session.
6. tmux a -t NAME_HERE - Attach to the tmux session named NAME_HERE.
7. CTRL-d - Delete (i.e. kill) currently-opened tmux session (alternatively tmux kill-session).
8. CTRL-b, [ - Enter copy mode, and enable scrolling in currently-opened tmux session. Press q to exit.
9. CTRL-b, " - Split window horizontally (i.e. split and add a pane below).

rafaeljesus

Important Notice

• ❗ All flags and settings described here are subject to change without any notice.
• Last update: September 2017

Introduction

This document describes a set of MySQL flags that have been tuned in Google Cloud SQL (Second Generation) to make the out-of-box experience better on Google Cloud. This is for your reference only, with the hope that some of the settings might also be useful outside the Google Cloud environment.

innodb_buffer_pool_size

rafaeljesus

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.

rafaeljesus

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:set nolist

" show hidden characters in Vim
:set list

" settings for hidden chars
" what particular chars they are displayed with
:set lcs=tab:▒░,trail:▓,nbsp:░
" or

rafaeljesus

What to Expect and Tips

• 45-minute systems interview, focus on responding to real world problems with an unhealthy service, such as a web server or database. The interview will start off at a high level troubleshooting a likely scenario, dig deeper to find the cause and some possible solutions for it. The goal is to probe your knowledge of systems at scale and under load, so keep in mind the challenges of the Facebook environment.
• Focus on things such as tooling, memory management and unix process lifecycle.

Systems

More specifically, linux troubleshooting and debugging. Understanding things like memory, io, cpu, shell, memory etc. would be pretty helpful. Knowing how to actually write a unix shell would also be a good idea. What tools might you use to debug something? On another note, this interview will likely push your boundaries of what you know (and how to implement it).

Design/Architecture 

Interview is all about taking an ambiguous question of how you might build a system and letting