"Effective approaches on working with huge ​˜legacy˜​ codebase" from Paul Taykalo

Did you ever face solution that has been transforming to legacy even before production? Paul Taykalo will reveal the scenarios how to handle this, how to postpone code transformation into legacy so the code will leave comfortable to work with through the whole project lifecycle. What's included: refactoring, unit tets, how to give the new life to already existing legacy, what's tech debt and how to pay it and even more interesting things. And the main one - how to stay with stable and qualitative feature delivery.

Transcript

1. EFFECTIVE APPROACHES WHEN WORKING WITH HUGE LEGACY CODEBASE BY PAUL TAYKALO, STANFY 1 — Paul Taykalo, UMT 2016
2. HELLO PAGE 2 — Paul Taykalo, UMT 2016
3. PLAN > What is Legacy Code > Problems with Legacy Code > Dealing with Legacy Code > Features vs Refactoring balance > Measure our Success :) 3 — Paul Taykalo, UMT 2016
4. WHAT IS LEGACY CODE? 4 — Paul Taykalo, UMT 2016
5. LEGACY CODE ISN'T ALWAYS A BAD CODE 5 — Paul Taykalo, UMT 2016
6. OTHER PEOPLE'S CODE IS NOT A LEGACY CODE 6 — Paul Taykalo, UMT 2016
7. Code without tests is bad code. It doesn't matter how well written it is — Michael C. Feathers 7 — Paul Taykalo, UMT 2016
8. WHY DO WE CARE ABOUT LEGACY CODE? 8 — Paul Taykalo, UMT 2016
9. LEGACY CODE IS... 9 — Paul Taykalo, UMT 2016
10. LEGACY CODE IS... UNMAINTAINABLE 10 — Paul Taykalo, UMT 2016
11. LEGACY CODE IS... COMPLEX 11 — Paul Taykalo, UMT 2016
12. LEGACY CODE IS... UNPREDICATABLE 12 — Paul Taykalo, UMT 2016
13. LEGACY CODE IS... TIME CONSUMING 13 — Paul Taykalo, UMT 2016
14. LEGACY CODE... STOPS FEATURES DELIVERY 14 — Paul Taykalo, UMT 2016
15. WHY DO WE WRITE IT? 15 — Paul Taykalo, UMT 2016
16. UNMAINTAINABLE CODE GENERATORS 16 — Paul Taykalo, UMT 2016
17. UNMAINTAINBLE CODE GENERATORS > "Technical Debt" > Code without Tests > Yet Another Architecture > Super Awesome Library X > Other people* 17 — Paul Taykalo, UMT 2016
18. DEALING WITH LEGACY CODE PREVENTIVE MEASURES 18 — Paul Taykalo, UMT 2016
19. JUST STOP WRITING CODE! 19 — Paul Taykalo, UMT 2016
20. JUST STOP WRITING CODE! > Less code - less errors > Less code is easier to read 20 — Paul Taykalo, UMT 2016
21. START ADDING TESTS! // TODO: Geek IMG 21 — Paul Taykalo, UMT 2016
22. If you don't write tests you will never learn how to write them, its better to write bad tests then not to write any 22 — Paul Taykalo, UMT 2016
23. DO CODE GENERATION 23 — Paul Taykalo, UMT 2016
24. LET OTHER PEOPLE READ YOUR CODE 24 — Paul Taykalo, UMT 2016
25. DEALING WITH LEGACY CODE KNOW YOUR STATUS 25 — Paul Taykalo, UMT 2016
26. DEALING WITH LEGACY CODE DECREASING AMOUNT OF UNWANTED CODE 26 — Paul Taykalo, UMT 2016
27. REMOVE OLD UNUSED CODE 27 — Paul Taykalo, UMT 2016
28. DEPRECATE UNWANTED CODE LEAVE WARNINGS AND TODOS 28 — Paul Taykalo, UMT 2016
29. LEAVE COMMENTS 29 — Paul Taykalo, UMT 2016
30. RECHECK YOUR DEPENDENCIES 30 — Paul Taykalo, UMT 2016
31. ADD TESTS ON CHANGES YOU MAKE DON'T USE "CHANGE AN PRAY" APPROACH 31 — Paul Taykalo, UMT 2016
32. USE TOOLS FOR REFACTORING 32 — Paul Taykalo, UMT 2016
33. ONE REFACTOR AT THE TIME 33 — Paul Taykalo, UMT 2016
34. STAY TO THE SAME ARCHITECTURE WITHIN THE PROJECT 34 — Paul Taykalo, UMT 2016
35. MAKE TEMPLATES FOR CLASSES OR BIG CODE PARTS 35 — Paul Taykalo, UMT 2016
36. DECREASE PROJECT SIZE 36 — Paul Taykalo, UMT 2016
37. DEALING WITH LEGACY CODE UNDERSTANDING WHAT'S GOING ON 37 — Paul Taykalo, UMT 2016
38. UNDERSTANDING WHAT'S GOING ON > Crashes > Bugs > Deadlocks > Data loss > Unexpected behaviours 38 — Paul Taykalo, UMT 2016
39. UNDERSTANDING WHAT'S GOING ON CRASH LOGGING 39 — Paul Taykalo, UMT 2016
40. UNDERSTANDING WHAT'S GOING ON CRASH LOGGING TOOLS > Crashlytics > HockeyApp > TestFlight 40 — Paul Taykalo, UMT 2016
41. UNDERSTANDING WHAT'S GOING ON DEBUGGING 41 — Paul Taykalo, UMT 2016
42. UNDERSTANDING WHAT'S GOING ON DEBUGGING TOOLS > Xcode > LLDB > Chisel > View Debugging 42 — Paul Taykalo, UMT 2016
43. UNDERSTANDING WHAT'S GOING ON REMOTE LOGGING 43 — Paul Taykalo, UMT 2016
44. UNDERSTANDING WHAT'S GOING ON REMOTE LOGGING TOOLS > Crashlytics > LogEntries 44 — Paul Taykalo, UMT 2016
45. REMINDER FIGHTING LEGACY CODE IS NOT OUR GOAL 45 — Paul Taykalo, UMT 2016
46. FEATURES DELIVERY WE AREN'T PAID FOR FIGHTING WITH TECHNICAL DEBT 46 — Paul Taykalo, UMT 2016
47. BUT EACH FEATURE > Adds more code > Adds complexity > Increases project size > Increases testing time 47 — Paul Taykalo, UMT 2016
48. BALANCING FEATURES AND TECH DEBT GROWTH 48 — Paul Taykalo, UMT 2016
49. DIFFERENT FEATURES TYPES 49 — Paul Taykalo, UMT 2016
50. DIFFERENT FEATURES TYPES > Affects nothing (independent) > Affects one localized previous feature > Affects multiple previous features > Affects all application 50 — Paul Taykalo, UMT 2016
51. 90/10 PRINCIPLE* 51 — Paul Taykalo, UMT 2016
52. MEASURE 52 — Paul Taykalo, UMT 2016
53. MEASURE PROJECT HEALTH 53 — Paul Taykalo, UMT 2016
54. MEASURE PROJECT HEALTH > Tests count > Test coverage > Code Lines Count > Tests Lines Count 54 — Paul Taykalo, UMT 2016
55. MEASURE PROJECT HEALTH > Crash-free users/sessions > Number of days since last incident > Amount of bugs create in the last X days > Regressions count 55 — Paul Taykalo, UMT 2016
56. MEASURE PROJECT SPEED 56 — Paul Taykalo, UMT 2016
57. MEASURE PROJECT SPEED > Project Features count 57 — Paul Taykalo, UMT 2016
58. RECAP 58 — Paul Taykalo, UMT 2016
59. RECAP > Get the project status > Set up goals > Tack changes > Stop writing Legacy Code 59 — Paul Taykalo, UMT 2016
60. STOP WRITING LEGACY CODE THANK YOU 60 — Paul Taykalo, UMT 2016
61. LINKS > https://vimeo.com/138774243?utmcampaign=iOS%2BDev %2BWeekly&utmmedium=email&utmsource=iOSDevWeeklyIssue _251 > https://tech.blacklane.com/2015/12/13/test- automation-for-ios/ > http://inessential.com/2016/06/03/ thecleanscreenhabit?utmcampaign=iOS%2BDev 61 — Paul Taykalo, UMT 2016
62. EFFECTIVE APPROACHES WHEN WORKING WITH HUGE LEGACY CODEBASE BY PAUL TAYKALO, STANFY 62 — Paul Taykalo, UMT 2016