What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.


Box metrics
  • elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
  • elem.clientLeft, elem.clientTop, elem.clientWidth, elem.clientHeight
  • elem.getClientRects(), elem.getBoundingClientRect()
View css
@import url(;
*, *::before, *::after {
box-sizing: border-box;
body {
background: #FDFDFD;
margin: 25px 0;
View The Three Go Landmines.markdown

There are three easy to make mistakes in go. I present them here in the way they are often found in the wild, not in the way that is easiest to understand.

All three of these mistakes have been made in Kubernetes code, getting past code review at least once each that I know of.

  1. Loop variables are scoped outside the loop.

What do these lines do? Make predictions and then scroll down.

func print(pi *int) { fmt.Println(*pi) }
View gist:0b8f26e91f2818bef460

General key themes:

  • Hiring is really hard. You’re not just hiring a “Rails Engineer” or a “Python Programmer” you’re hiring someone who can help you change the world. Tell them why! Talk about the hard problems you’re solving. 2/3 of these talks give ideas and insight into hiring from sourcing to actual interview processes.

  • Rewriting systems is hard. People think they are going to replace their broken down horse and buggie with a bullet train and this often ends up in disaster. Successful rewrites require an incremental approach that takes months/years and often runs way over schedule. 2/3 of these talks go over how to handle rewrites not only from a high level technical perspective but a cultural/management perspective as well.

Two Developers, Many Lines of Code, and A Campaign that Made History

Harper Reed (CTO of Obama for America, now CEO of Modest) and Dylan Richard (Director of Eng of Obama for America, now CTO of Modest)

# List unique values in a DataFrame column
# h/t @makmanalp for the updated syntax!
df['Column Name'].unique()
# Convert Series datatype to numeric (will error if column has non-numeric values)
# h/t @makmanalp
pd.to_numeric(df['Column Name'])
# Convert Series datatype to numeric, changing non-numeric values to NaN
# h/t @makmanalp for the updated syntax!
View sm-annotated.html
<script type="text/javascript">
(function () {
"use strict";
// once cached, the css file is stored on the client forever unless
// the URL below is changed. Any change will invalidate the cache
var css_href = './index_files/web-fonts.css';
// a simple event handler wrapper
function on(el, ev, callback) {
if (el.addEventListener) {
el.addEventListener(ev, callback, false);
#!/usr/bin/env python
from sys import argv
if len(argv) != 2:
print('usage: %s filename.kv' % argv[0])
from kivy.lang import Builder
from import App
View L.CanvasOverlay.js
UPDATE July 2016 , moved and updated to here:
Generic Canvas Overlay for leaflet,
Stanislav Sumbera, April , 2014
- added userDrawFunc that is called when Canvas need to be redrawn
- added few useful params fro userDrawFunc callback
- fixed resize map bug
inspired & portions taken from :
import asyncio
import tornado.concurrent
import tornado.ioloop
import tornado.web
import tornado.platform.asyncio
import tornado.httpclient
class ReqHandler(tornado.web.RequestHandler):
async def get(self):