Why?

It's hard enough to find an error in your code when you're looking for it;

it's even harder

when you've assumed your code is error-free. 

              Steve McConnell

Any resemblance to actual browser logos is purely coincidental.

Bugs will still get into production

no matter what.

(c) Matt Robenolt: Everything is broken, and I don't know why! [JSConf2014]

What?

What to track?

• Error message
• Error trace
• Error level
• URL
• Browser & OS
• User ID
• App state
• Release number

Release number

Do know your errors

• Fatal, Warning, Notice

• System vs User

• Local vs Global

and What not?

• localhost (Test/Dev environment)
• old browsers
• known browser extension issues 

How?

All you need to do

• capture error
• send to the server
• own errors
• typeof new Error('lol').stack
• framework specific

Use Tools!

Key features

• SSL
• Notifications
• Webhooks
• Useful Search/Filtering
• Integrations: GitHub, Jira, Slack, HipChat...
• Dupe detection
• Comprehensive read & write API
• Deploy tracking
• Source map support
• Knows your framework

Sourcemaps for

Minified code experience

Providing Sourcemaps

• publicly hosted
• curl
• sentry-cli

Sourcemaps experience:

Being more friendly with you users:

+

Standard flow

Be more proactive!

under the hood

our API

webhook

 API

webhook

our API

 API

shows what user did before the BUG happened

kuoll.com

Demo

70% discount promocode - KUOLL70

How it works

• Record is stored in the browser IndexedDB until a bug
  detected

• Stores/replays using HTML DOM mutations deltas

• Complete HTTP XHR request/response is stored (with
  content and headers)

• Events are connected together into cause-effect
  chains. A chain example: user click -> request ->
  response -> dom-mutation.

Let's do together

https://goo.gl/3W5438