rafaeljesus

type HttpResp struct {
    Id   string
    Resp *http.Response
    Err  error
}
 
func AsyncGet(urls map[string]string) []*HttpResp {
    ch := make(chan *HttpResp)
    responses := []*HttpResp{}
 

rafaeljesus

var Promise = require('bluebird');

var funcs = Promise.resolve([500, 100, 400, 200].map((n) => makeWait(n)));

funcs
  .each(iterator)       // logs: 500, 100, 400, 200
  .then(console.log)    // logs: [ [Function], [Function], [Function], [Function] ]

funcs
  .mapSeries(iterator)  // logs: 500, 100, 400, 200

rafaeljesus

(() => {
  let count = 0;

  function getAllButtons() {
    return document.querySelectorAll('button.is-following') || [];
  }

  async function unfollowAll() {
    const buttons = getAllButtons();

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

module "vpc" {
  source = "git::git@github.com:rafaeljesus/vpc?ref=master"

  vpc_id          = var.vpc_id
  vpc_cidr_block  = var.vpc_cidr_block
  azs             = slice(data.aws_availability_zones.available.names, 0, 3)
  public_subnets  = var.vpc_public_subnets
  private_subnets = var.vpc_private_subnets
  igw_id          = var.vpc_igw_id

rafaeljesus

receivers:
###################################################
## Slack Receivers
- name: slack-code-owners
  slack_configs:
  - channel: '#{{- template "slack.monzo.code_owner_channel" . -}}'
    send_resolved: true
    title: '{{ template "slack.monzo.title" . }}'
    icon_emoji: '{{ template "slack.monzo.icon_emoji" . }}'
    color: '{{ template "slack.monzo.color" . }}'