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🧠 System Design Fundamentals — Engineer Gist

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1️⃣ Scalability

Meaning: Ability of system to handle growth (users, data, traffic).

Types

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🧠 Mock Interview: Advanced Ruby (Pure Ruby / Automation)

1. Ruby Object Model

Q1. How does Ruby resolve a method call?

Model Answer

When Ruby receives a method call, it starts lookup from the object’s singleton class, then moves to the object’s class, followed by any prepended modules, then included modules (in reverse order), and continues up the superclass chain until BasicObject.

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🧠 Data Structures & Algorithms – Complexity + Why Cheat Sheet

Quick reference for time/space complexity plus why & when to use each algorithm. Perfect for interviews, revisions, and system thinking.

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🔁 Sorting Algorithms

| Algorithm | Best | Avg | Worst | Space | Why / When to use |

vishalzambre

module StringToBooleanRefinementsService
  refine String do
    def to_bool
      return true  if self == true   || self =~ /(true|t|yes|y|1)$/i
      return false if self == false  || self.blank? || self =~ /(false|f|no|n|0)$/i

      raise ArgumentError, "invalid value for Boolean: \"#{self}\""
    end

    alias_method :to_b, :to_bool

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## Add System Service for Resque

Copy below code and paste to /lib/systemd/system/resque.service
`vim /lib/systemd/system/resque.service`

```shell
[Unit]
Description=Resque Workers

[Service]

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begin
  require "bundler/inline"
rescue LoadError => e
  $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler"
  raise e
end

gemfile(true) do
  source "https://rubygems.org"
  gem "rails", github: "rails/rails"

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begin
  require "bundler/inline"
rescue LoadError => e
  $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler"
  raise e
end

gemfile(true) do
  source "https://rubygems.org"
  # Activate the gem you are reporting the issue against.

vishalzambre

begin
  require "bundler/inline"
rescue LoadError => e
  $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler"
  raise e
end

gemfile(true) do
  source "https://rubygems.org"
  # Activate the gem you are reporting the issue against.

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# lib/tasks/db.rake
namespace :db do

  desc 'Dumps the database to db/APP_NAME.dump'
  task dump: :environment do
    cmd = nil
    with_config do |app, host, port, db, user, password|
      cmd = "PGPASSWORD='#{password}' pg_dump --host #{host} --username #{user} -p #{port} --verbose --clean --no-owner --no-acl --format=c #{db} > #{Rails.root}/db/#{app}.dump"
    end
    puts cmd

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begin
  require 'bundler/inline'
rescue LoadError => e
  $stderr.puts 'Bundler version 1.10 or later is required. Please update your Bundler'
  raise e
end

gemfile(true) do
  source 'https://rubygems.org'
  # Activate the gem you are reporting the issue against.