harlow

Observability in micro-service architectures

Concurrency Is Not Parallelism

General coding

go tooling in action

justforfunc refactoring

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Recently, we were fortunate to bring together top CTO talent from inside and outside the First Round Community to share best practices, challenges and insights. Key topics included how to create a great management team, introducing structure to your org, and tools for better technical productivity. Notes from this session are below.

BUILDING STRONG MANAGEMENT

• It's easy to build a management structure when things are early and small. But don't over-optimize this structure. It will change as you bring people on. For example, don't give out management titles until you have at least four teams.
• The best tactic is to have everyone start out as an engineer, then hire an engineering director and split the team in half. This is the cell-splitting model -- grow a team then split it into different cells.
• Don't promote people into management roles too early. It's better to hire a manager than to promote from within the ranks. The latter only causes conflict.
• Always remember, while someone might be a bril

harlow

aaron,erin,ron,ronnie
abel,ab,abe,eb,ebbie
abiel,ab
abigail,abby,gail,gail,nabby
abner,ab
abraham,ab,abe
abram,ab
adaline,ada,addy,delia,dell,lena
adelaide,addy,adele,dell,della,heidi
adeline,ada,addy,delia,dell,lena

harlow

package main

import (
	"github.com/apex/go-apex"
	"github.com/apex/go-apex/kinesis"
	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/firehose"
)

harlow

console.log('Loading function');

exports.handler = function(event, context) {
    //console.log('Received event:', JSON.stringify(event, null, 2));
    event.Records.forEach(function(record) {
        // Kinesis data is base64 encoded so decode here
        var payload = new Buffer(record.kinesis.data, 'base64').toString('ascii');
        console.log('Decoded payload:', payload);
    });
    context.succeed("Successfully processed " + event.Records.length + " records.");

harlow

{
  "id": "custom_id", // the webhook_id passed in the lookup params
  "status": 200,
  "type": "company",
  "body": {
    // Company attributes
  }
}

harlow

Golang Workers / Job Queue

A running example of the code from:

• http://marcio.io/2015/07/handling-1-million-requests-per-minute-with-golang
• http://nesv.github.io/golang/2014/02/25/worker-queues-in-go.html

This gist creates a working example from blog post, and a alternate example using simple worker pool.

TLDR: if you want simple and controlled concurrency use a worker pool.

harlow

My issues with Modules

In researching topics for RailsCasts I often read code in Rails and other gems. This is a great exercise to do. Not only will you pick up some coding tips, but it can help you better understand what makes code readable.

A common practice to organize code in gems is to divide it into modules. When this is done extensively I find it becomes very difficult to read. Before I explain further, a quick detour on instance_eval.

You can find instance_eval used in many DSLs: from routes to state machines. Here's an example from Thinking Sphinx.

class Article < ActiveRecord::Base

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{
  "id": "d5639304-f15a-48b5-9711-7bd42e6c4d72",
  "name": "HotelTonight",
  "legalName": "HotelTonight, Inc",
  "domain": "hoteltonight.com",
  "url": "http://hoteltonight.com",
  "site": {
    "url": "http://hoteltonight.com",
    "title": "HotelTonight | Last-Minute Deals on Great Hotels",
    "h1": "PLAN LESS. ",

harlow

require 'sinatra/base'

class FakeGitHub < Sinatra::Base
  cattr_reader :emulate_failure
  
  def self.reset!
    @@emulate_failure = false
  end
  
  def self.emulate_failure!