Lessons Learned from a Re(design|write)

My thoughts on redesigning and rewriting an application from PHP -> Python

Transcript

1. Lessons Learned from a Re(write|design) Diving into the world of feature-flipping, performance optimization and removing of technical debt.
2. Adam McKerlie WWCC 2 About me Hi, I’m Adam McKerlie. I’m a python developer at G Adventures. I like good beer, optimizing SQL queries and making stuff run. You can contact me at Twitter @adammckerlie IRC silent1mezzo Web procrastinatingdev.com
3. Adam McKerlie 3 Then vs Now
4. Adam McKerlie 4 Why Rewrite a Working Application? • Other teams were using Python/Django • Codebase was getting unmaintainable • Easier to hire
5. How Did We Do It?
6. Two Applications One Login
7. Adam McKerlie 7 • Authenticated on the PHP side • PHP sent a request to Django with the username, password hash and secret • Authenticated in Django when the user visited the site
8. One App at a Time
9. Adam McKerlie 9 • Built what we thought users would need the most • Specifications from Business • Launched side-by-side with old site • Turned off old site once we confirmed everything was working
10. Feature Flipping
11. Adam McKerlie WWCC 11 • Django Waffle (https://github.com/jsocol/django-waffle) • Views • Templates
12. Contest Rollout
13. Adam McKerlie 13 • Small core group of users • We gave out invites to those users when they suggested ideas • Those invites were then sent out to other users • Eventually we flipped the flag for everyone
14. Template Structure
15. Adam McKerlie 15 • New design moved to new/ • Same for Static
16. Realization #1 Specifications Change Quickly
17. Adam McKerlie WWCC 17 • Don’t get too attached • Need to know the business to anticipate changes • Learn to say no
18. Realization #2 Your Users aren’t Always Right
19. Adam McKerlie 19 • They only know from what they’ve seen • They don’t know the technology • You can tell them what they want • Be ready to learn from them
20. Realization #2 The ORM is Great...Until it’s Not
21. Adam McKerlie Realization #2 The ORM is Great...Until it’s Not 21 Bad
22. Adam McKerlie Realization #2 The ORM is Great...Until it’s Not 22 Better
23. Adam McKerlie Realization #2 The ORM is Great...Until it’s Not 23 Wat?
24. Adam McKerlie Realization #2 The ORM is Great...Until it’s Not 24 Best
25. Adam McKerlie 25 • Can produce some very weird (slow) joins • Hundreds of fast queries can kill a page • One slow query can also kill a page
26. Realization #4 People with Slow Internet Connections Don’t Notice Performance Gains
27. Adam McKerlie WWCC 27 • When they’re used to waiting a few minutes per page load, 45 second page decrease doesn’t make much of a difference • Youtube
28. Realization #5 Simple Features get the Most Praise
29. Adam McKerlie 29 • Lots of feedback and praise • *Crickets*
30. Realization #6 People Don’t Use Your Application in Ways You Expect
31. Adam McKerlie 31 • Saving after every change instead of a final save • Importance of seeing what your users do • Mixpanel, Clicktale, In Person
32. Thanks! Questions?