The Perils Of Software Engineering

My keynote from PyCon SG 2015.

Transcript

1. Andrew Godwin
   @andrewgodwin
   PERILS
   OF
   THE
   SOFTWARE
   ENGINEERING
   

   View Slide

2. Andrew Godwin
   Hi, I'm
   Django Core Developer
   Senior Engineer at
   Far too many hobbies
   

   View Slide

3. "Perils"
   

   View Slide

4. Computer Science
   ≠
   Software Engineering
   

   View Slide

5. Engineering
   Mechanical
   Civil
   Software
   Chemical
   Materials
   

   View Slide

6. Mechanical Engineering
   https://www.flickr.com/photos/mariaeklind/
   

   View Slide

7. Nondeterministic
   

   View Slide

8. Cost of Entry
   

   View Slide

9. Civil Engineering
   

   View Slide

10. Timescales
    

    View Slide

11. Cost of Failure
    

    View Slide

12. Aerospace
    Software Engineering
    

    View Slide

13. Cost of Failure
    

    View Slide

14. Failure: When, not if
    

    View Slide

15. Margaret Hamilton, 1969
    

    View Slide

16. Apollo 11 LM, "Eagle"
    

    View Slide

17. Web/App
    Software Engineering
    

    View Slide

18. Quick to build and test
    

    View Slide

19. Minimal equipment costs
    

    View Slide

20. Well-paid
    

    View Slide

21. Well-paid
    

    View Slide

22. Explicit is better than Implicit
    

    View Slide

23. Code Indirection
    

    View Slide

24. class MyView(View):
    def get(self, request):
    return self.render(request, "template.html")
    

    View Slide

25. class MyView(FormView, AuditMixin, OtherMixin):
    def get(self, request):
    return self.render(request, "template.html")
    class AuditMixin(BaseAuditor, AdditionalStuff):
    ...
    class OtherMixin(MyObject, SomethingElse):
    ...
    

    View Slide

26. Async Uncertainty
    

    View Slide

27. def async_handler():
    with open("my_file.txt", "r") as fh:
    write_socket(1, fh.read())
    redis.incr("key1", 2)
    

    View Slide

28. Schemas
    

    View Slide

29. {
    "id": 342,
    "name": "David",
    "weight": 74,
    }
    {
    "id": 342,
    "name": "Ellie",
    "weight": "85kg",
    }
    {
    "id": 342,
    "nom": "Frankie",
    "weight": 77,
    }
    {
    "id": 342,
    "name": "Frankie",
    "weight": -67,
    }
    

    View Slide

30. Clever code is bad
    Maintainable code is good
    

    View Slide

31. xs = [number for inner in nested
    if len(inner) > 2 for number in inner]
    

    View Slide

32. for inner in nested:
    if len(inner) > 2:
    for number in inner:
    xs.append(number)
    

    View Slide

33. Explore and Discard
    

    View Slide

34. There is no perfect solution
    

    View Slide

35. Throwing everything away
    rarely works
    

    View Slide

36. Backwards compatability
    is your friend
    

    View Slide

37. Nobody is a genius;
    we're all mediocre
    

    View Slide

38. Argue over code,
    not over ideas
    

    View Slide

39. Well-paid
    

    View Slide

40. 10 years?
    100 years?
    1000 years?
    

    View Slide

41. Who will access it?
    

    View Slide

42. What format will it be?
    

    View Slide

43. Is it even important?
    

    View Slide

44. Over thousands of years, the
    machine memories have been
    filled with programs that can help
    “
    “
    A Deepness In The Sky
    Vernor Vinge
    

    View Slide

45. Engineering is collaborative
    

    View Slide

46. Build well.
    

    View Slide

47. Thanks.
    Andrew Godwin
    @andrewgodwin
    

    View Slide