Make legacy great again @ PHPAmersfoort

How to deal with legacy code? Where to start? What is legacy code anyways? This talk was held during PHP user group meetup at Amersfoort at 13th of Dec

Transcript

1. MAKE LEGACY GREAT AGAIN. It was perfect when I wrote it!
2. DONATAS. Part of Coolblue.
3. • One of the largest e-commerce companies in the Benelux • > 2,5k employees, > 300 webshops, 8 physical stores, 2 warehouses • All mission-critical software developed in-house • 100% growth every 20 months ABOUT COOLBLUE.
4. MAKE LEGACY GREAT AGAIN. It was perfect when I wrote it!
6. OLDEST PIECE OF CODE. 2004. PHP4.
7. AGENDA.
8. NOT A SILVER BULLET.
9. EVERYTHING. is legacy.
10. DIVING INTO LEGACY.
11. ITS YOUR LEGACY.
12. CODE FOR SILENT PSYCHOPATH WHO KNOWS WHERE YOU LIVE.
13. SOLID LEGACY = GOOD LEGACY.
14. LEGACY MAKES YOU MONEY.
15. WE ARE DETECTIVES.
16. POKE IT.
17. FIDDLE AROUND.
18. TAME THE BEAST.
19. UNDERSTANDING HOW LEGACY WORKS = PATH TO WIN.
20. HALF A YEAR TO MAKE RATIONAL CHOICES.
21. 100% IS NEVER WORTH IT.
22. WRITE NEW CODE. you must
23. DON’T WRITE MORE LEGACY.
24. SIMPLE START:
 PSR, SOLID, TESTS AFTER.
25. MIX OLD AND NEW, 
 SPREAD WIDELY.
26. WHY REPEAT THE SAME MISTAKES?
27. DON’T BREAK MORE WINDOWS.
28. MINDSET IS HARDEST THING TO CHANGE.
29. EMBRACE THE FAILURE.
30. BAD LEGACY ALWAYS BREAKS.
31. BETTER DETECTIVES CREATE LESS BROKEN BUILDS.
32. SECRET INGREDIENT 1/2: 
 BREAK PRODUCTION.
33. SECRET INGREDIENT 2/2: 
 LEARN FROM MISTAKES.
34. THE WHEEL. Already invented.
35. EVERYTHING IS CUSTOM IN LEGACY CODE.
36. SOLID LEGACY = GOOD LEGACY.
37. DO YOU CREATE NEW FUNCTIONALITY IN BAD LEGACY?
38. STAND ON THE SHOULDERS OF GIANTS.
39. FOCUS ON VALUE FOR THE CUSTOMERS.
40. FOCUS ON BUSINESS PROBLEMS WHICH ARE NOT IN PACKAGIST.
41. TOOLS. Automate all the things.
42. • PHP_CodeSniffer • PHPMetrics • PHPMD • PHP Depend TOOLS.
43. AWARENESS AND VISIBILITY HELPS TO IMPROVE.
44. PREVENTING BAD LEGACY.
45. WAR STORIES.
46. MAIN(), INIT(), LOAD(), __CALL().
47. AUTOMATIC REFACTORING WITH PHPSTORM.
49. INPUT/OUTPUT METHOD IS 
 CLEAN AND TESTABLE CODE.
50. LEAVE MESS FOR LATER, 
 BUT LESS EVERY TIME.
51. ROUTING MESS.
52. ROUTING CHOICE.
53. WORK WORK WORK 
 (WITH TDD).
54. D-DAY - SO SMOOTH.
55. TEMPLATES. BUSINESS LOGIC, DB CALLS, UNTESTED CALCULATIONS.
56. INTERFACE TEMPLATES FOR EASIER REFACTORING.
57. HOW DID YOU IMPROVE CODE TODAY?
58. WHAT IS THE MOST IMPORTANT SKILL FOR DEVELOPER?
60. REWIRING AND UNDERSTANDING.
61. EXERCISE OF MIND, 
 NOT BODY.
62. SCIENCE FAILED 
 THE FIRST TIME.
63. REFACTORING.
65. REFACTORING - IMPROVING CODE WITHOUT CHANGING BEHAVIOUR.
66. REFACTORING - AN ART FORM.
67. COMMUNICATION IS IMPORTANT.
68. FAIL, READ, LEARN.
 RINSE AND REPEAT.
69. GRUMPY CATS. They’re always everywhere and grumpy
70. DEVELOPERS WANT TO BUILD QUALITY CODE.
71. YOU DECIDE YOUR LEGACY.
72. CUSTOMERS DEPEND ON YOU.
73. SHARE THE BENEFITS.
 VISUALISE THE PROBLEMS.
74. GRUMPY = LOST OR DEFENSIVE.
 HELP THEM. 
 DON’T SCOLD.
75. OUTRO. Yes, I’m finally shutting up.
76. REFACTORING IS A BIG TOPIC.
77. NOT A SILVER BULLET.
78. • Working Effectively with Legacy Code • sourcemaking.com • … ? SOURCES FOR INSPIRATION.
79. I WANT YOU TO EMBRACE IT.
80. FAVOUR TESTED, SOLID LIBRARIES OVER CUSTOM CODE.
81. SOFTWARE IS ALIVE.
 FOCUS ON TODAY.
82. KNOWING ART OF REFACTORING
 WILL MAKE LEGACY GREAT!
83. THANK YOU. Questions/Feedback? Tweet @donis_plays
 Spam donis@gildija.lt