vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

karpathy

"""
Minimal character-level Vanilla RNN model. Written by Andrej Karpathy (@karpathy)
BSD License
"""
import numpy as np

# data I/O
data = open('input.txt', 'r').read() # should be simple plain text file
chars = list(set(data))
data_size, vocab_size = len(data), len(chars)

lelandbatey

Description

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

Results

jonathantneal

Font Face

A mixin for writing @font-face rules in SASS.

Usage

Create a font face rule. Embedded OpenType, WOFF2, WOFF, TrueType, and SVG files are automatically sourced.

@include font-face(Samplino, fonts/Samplino);

adamwiggins

Make it real

Ideas are cheap. Make a prototype, sketch a CLI session, draw a wireframe. Discuss around concrete examples, not hand-waving abstractions. Don't say you did something, provide a URL that proves it.

Ship it

Nothing is real until it's being used by a real user. This doesn't mean you make a prototype in the morning and blog about it in the evening. It means you find one person you believe your product will help and try to get them to use it.

Do it with style

Integralist

Table of Contents

• Strings
• Fretboard
• Intervals
  • Quantity
  • Quality
• Scales
  • Chromatic
• Diatonic

bsergean

Getting the code

git clone https://gist.github.com/08be90a2f21205062ccc.git

Executing the code

$ npm install # maybe npm start will take care of it but just in case
$ npm start && open out.png

> offscreen-sample@1.0.0 start /Users/bsergean/src/offscreen_sample

MichaelSimons

Retrieving Docker Image Sizes

There are two metrics that are important to consider when discussing the size of Docker images.

1. Compressed size - This is often referred to as the wire size. This affects how fast/slow images can be pulled from a registry. This impacts the first run experience on machines where images are not cached.
2. Uncompressed size - This is often referred to as the size on disk. This affects how much local storage is required to support your Docker workloads.

The example commands shown below will work on Windows, MacOS, and Linux.

How to Measure the Compressed Size

chrismdp

# You don't need Fog in Ruby or some other library to upload to S3 -- shell works perfectly fine
# This is how I upload my new Sol Trader builds (http://soltrader.net)
# Based on a modified script from here: http://tmont.com/blargh/2014/1/uploading-to-s3-in-bash

S3KEY="my aws key"
S3SECRET="my aws secret" # pass these in

function putS3
{
  path=$1

debashisbarman

Creating a Twitter bot with Node.js

Learn how you can create your own Twitter bot using Node.js and the new Twitter API. The bot will auto retweet in response to tweets with some particular hashtags. (https://goo.gl/4whEIt)

Tools we need

Here are the tools we’ll be using to create the bot — 

• Node.js installed in your machine
• A registered Twitter account

Create a Twitter application