Migrating to Clojure. So much fn.

Slides from a talk I delivered on 27.02.2014 at Lambda Days in Kraków, Poland.

1. Migrating to Clojure So much fn @janstepien
2. I work at
3. I work at
5. © Seph Swain 2008 flickr.com/photos/seph_swain/2735367665
6. (something new)
7. © Seph Swain 2008 flickr.com/photos/seph_swain/2741483308
9. feature freeze! no
10. ↓ ╭────────────╮ │ http proxy │ ╰────────────╯ ↓ ↓ ╭───────────────╮ ╭─────────────╮ │ ruby on rails │ ← │ widgets! │ ╰───────────────╯ ╰─────────────╯ ↓ ╭──────╮ │ db │ ╰──────╯
11. ↓ ╭────────────╮ │ http proxy │ ╰────────────╯ ↓ ↓ ╭───────────────╮ ╭─────────────╮ │ ruby on rails │ │ widgets! │ ╰───────────────╯ ╰─────────────╯ ↓ ↓ ╭──────╮ ╭─────────────╮ │ db │ ← │ data acc. │ ╰──────╯ ╰─────────────╯
12. ↓ ╭───────────────────────╮ │ │ │ ╭───────╯ │ ruby on rails │ ↓ │ │ ╭─────────────╮ │ │ │ widgets! │ ╰───────────────╯ ╰─────────────╯ ↓ ↓ ╭──────╮ ╭─────────────╮ │ db │ ← │ data acc. │ ╰──────╯ ╰─────────────╯
13. /colour-red /50-100-euro /jeans/esprit
14. ↓ ╭───────────────────────╮ │ │ │ ╭───────╯ │ ruby on rails │ ↓ │ │ ╭─────────────╮ │ │ │ widgets! │ ╰───────────────╯ ╰─────────────╯ ↓ ↓ ╭──────╮ ╭─────────────╮ │ db │ ← │ data acc. │ ╰──────╯ ╰─────────────╯
15. ↓ ╭───────────────────────╮ │ │ │ ╭───────╯ │ ruby on rails │ ↓ │ │ ╭─────────────╮ │ │ │ clojure │ ╰───────────────╯ ╰─────────────╯ ↓ ↓ ╭──────╮ ╭─────────────╮ │ db │ ← │ data acc. │ ╰──────╯ ╰─────────────╯
16. (cons )
17. a slide intentionally left blank
18. widgets the cornerstone
19. {:fetch (fn [env] (get-data-for env)) :view (fn [fetched-data] (render fetched-data))}
20. (map render widgets) ↓ (pmap render widgets)
21. templating worst nightmare
22. © omefrans 2010 flickr.com/photos/omefrans/4238610113
23. <div id=”main”> text </div> {:tag :div :attr {:id ”main”} :content [”text”]}
24. repl everywhere
25. tools to the rescue
26. before 54 machines
27. after 10 machines* * traffic grew twofold
28. mistakes we made a lot
29. (my {:yet :another} (somewhat [:helpful]) (dsl!))
30. hiring not as bad as it seems
31. future a lot to be done
32. summing it up it was a good idea
33. Migrating to Clojure So much fn jan.stepien@stylefruits.de jan@stepien.cc @janstepien