I am bad at my job.

App Academy - September 28th 2017

Transcript

1. I am bad at my job. App Academy September 28th 2017 Matt Robenolt Matt
2. hello @mattrobenolt
3. Principal Software Engineer
4. This computer stuff is really hard.
6. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; }
7. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } $ ./program
8. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } $ ./program 10 20 619512036
9. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } $ ./program 10 20 619512036 $ ./program 10 20 369033241
10. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } Physical Memory Chip 0x0000 0x0004 4 bytes 0x0008 0x000C 0xFFFF
11. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } Physical Memory Chip 0x0000 0x0004 4 bytes 0x0008 0x000C 0xFFFF 0x0000 (0)
12. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } Physical Memory Chip 0x0000 0x0004 4 bytes 0x0008 0x000C 0xFFFF 0x000A (10) 0x0014 (20) 0x0000 (0)
13. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } Physical Memory Chip 0x0000 4 bytes 0x0008 0x000C 0xFFFF 0x000A (10) 0x0014 (20) 0x0000 (0) 0x0004
14. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } Physical Memory Chip 0x0000 4 bytes 0x0008 0x000C 0xFFFF 0x000A (10) 0x0014 (20) 0x0000 (0) 0x0004 “address of things” + (i * sizeof(int))
15. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } Physical Memory Chip 0x0000 4 bytes 0x0008 0x000C 0xFFFF 0x000A (10) 0x0014 (20) 0x0000 (0) 0x0004 0x0004 + (0 * 4) == 0x0004 &0x0004 == 0x000A (10)
16. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } Physical Memory Chip 0x0000 4 bytes 0x0008 0x000C 0xFFFF 0x000A (10) 0x0014 (20) 0x0001 (1) 0x0004
17. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } Physical Memory Chip 0x0000 4 bytes 0x0008 0x000C 0xFFFF 0x000A (10) 0x0014 (20) 0x0001 (1) 0x0004 0x0004 + (1 * 4) == 0x0008 &0x0008 == 0x0014 (20)
18. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } Physical Memory Chip 0x0000 4 bytes 0x0008 0x000C 0xFFFF 0x000A (10) 0x0014 (20) 0x0002 (2) 0x0004
19. #include <stdio.h> int main() { int i = 0; int things[] = {10, 20}; for (; i < 3; i++) { printf("%d\n", things[i]); } return 0; } Physical Memory Chip 0x0000 4 bytes 0x0008 0x000C 0xFFFF 0x000A (10) 0x0014 (20) 0x0002 (2) 0x0004 0x0004 + (2 * 4) == 0x000C &0x000C == ???? ????
20. JavaScript is especially hard.
21. sentry $ find node_modules -type f | wc -l 36882 sentry $ du -hs node_modules 308M node_modules
22. function multiply() { var rv = 1; for (var i = 0; i < arguments.length; i++) rv += arguments[i]; return rv; } > multiply(2, 2) <- 4
23. test('multiply 2 * 2 to equal 4', () => { expect(multiply(2, 2)).toBe(4); }); 100% test coverage btw
24. > multiply(2, 2) <- 4
25. > multiply(2, 2) <- 4 > multiply() <- 1
26. > multiply(2, 2) <- 4 > multiply() <- 1 > multiply(1, 1) <- 3
27. > multiply(2, 2) <- 4 > multiply() <- 1 > multiply(1, 1) <- 3 > multiply(1, {}) <- "2[object Object]"
28. Shipping code is the worst.
29. window.Notification.requestPermission().then(function() { new Notification("I see you."); });
30. Yas, I did it!
31. I think my computer is broken.
32. Step 1:
33. Step 1: Acceptance
34. This is hard. But that’s ok.
35. Step 2:
36. Step 2: Self-awareness
37. You won’t know everything. You will make mistakes. But that’s OK.
38. Step 3:
39. Step 3: Do your best
40. Learn from mistakes. assume the worst.
41. How to deal with production.
42. Bug-free code is very rare.
43. Respond quickly when things are broken.
44. Monitoring is good.
45. Meet Sentry.
46. Error reporting
47. window.Notification.requestPermission().then(function() { new Notification("I see you."); });
50. Context is good.
51. Questions? I may or may not have answers. @mattrobenolt github.com/mattrobenolt sentry.io github.com/getsentry/sentry