'Always wear underwear' and other practical advice for Computer Science students. A transcript of the talk is available at www.netmeister.org/blog/semper-ubi-sub-ubi.html

1. Semper
Ubi
Sub
Ubi
…and
other
advice.
An
incomplete
list
of
things
they
don’t
teach
you
in
school.
@jschauma

3. Know
your
Unknowns.
@jschauma

4. @jschauma

5. @jschauma

6. @jschauma

7. Computering,
at
its
heart,
is
a
people
problem.
@jschauma

8. “A
concept
is
stronger
than
a
fact.”
@jschauma
-­‐-­‐
CharloEe
Perkins
Gilman

9. @jschauma

10. You
need
pracIcal
programming
experience.
@jschauma

11. You
don’t
fully
understand
a
problem
unIl
you
try
to
solve
it
yourself.
@jschauma

12. Prototype…
then
toss
it.
(Beware
Second
System
Syndrome.)
@jschauma

13. @jschauma

14. Perfect
is
the
enemy
of
the
Good.
@jschauma

15. Worse
is
BeEer.
@jschauma
Perfect
is
the
enemy
of
the
Good.

16. Worse
is
BeEer.
@jschauma
Perfect
is
the
enemy
of
the
Good.
“Good
enough”
oPen
is
the
enemy
of
“actually
good”.

17. Simplify.
@jschauma

18. “This
is
the
Unix
philosophy:
Write
programs
that
do
one
thing
and
do
it
well.
Write
programs
to
work
together.
Write
programs
to
handle
text
streams,
because
that
is
a
universal
interface.”
@jschauma
-­‐-­‐
Douglas
McIllroy

19. Know
Unix.
Embrace
the
command-­‐line.
@jschauma

20. Know
your
$EDITOR.
@jschauma

21. Know
how
to
use
a
debugger.
printf(“here: x is now %dn”, x);!
!
does
not
count.
@jschauma

22. Meet
your
new
friends,
the
Straces:
dtrace(1),
ktrace(1),
strace(1)
@jschauma

23. Use
boring
technology.
@jschauma

24. Use
boring
technology.
Write
boring
code.
@jschauma

25. $ echo ‘import this’ | python
@jschauma

26. Readability
counts.
@jschauma

27. Refactor
if:
-­‐
code
trails
off
right
side
of
your
window
-­‐
your
funcIon
does
not
fit
into
<200
lines
@jschauma
Readability
counts.

28. Readability
counts.
You
are
not
charged
per
character.
@jschauma

29. (Most)
comments
considered
harmful.
@jschauma

30. @jschauma
// increment x by 2
x = x + 2;

31. @jschauma
// increment x by 2
x = x + 4;

32. (Most)
comments
considered
harmful.
Comments
should
explain
the
why,
not
the
what.
@jschauma

33. Write
The
Fine
Manual
@jschauma

34. @jschauma
$ cp /usr/share/man/man1/ls.1 hfrob.1
$ $EDITOR hfrob.1
$ nroff -man hfrob.1 | more

35. Write
The
Fine
Test
Suite
@jschauma

36. Write
meaningful
error
messages.
@jschauma
$ hfrob frumbl
Error!
$ echo $?
0
$
$ hfrob frumbl
Unable to open file: ‘/usr/share/hfrob/frumbl’: No
such file or directory.
$ echo $?
1
$
✔︎

37. Learn
to
write
a
bug
report.
@jschauma

38. Try
to
understand
what
you’re
doing.
@jschauma

39. @jschauma

40. Sufficiently
advanced
cheaIng
is
indisInguishable
from
learning.
@jschauma

41. Computering,
at
its
heart,
is
a
people
problem.
SoPware
development
is
a
social
acIvity.
@jschauma

42. Learn
to
write
an
email.
@jschauma
http://www.phdcomics.com/comics.php?f=1795

43. The
internet
does
not
forget.
Anything.
Ever.
@jschauma

44. Other
people
are…
…also
people.
@jschauma

45. @jschauma

46. Own
your
mistakes.
@jschauma

47. You
break
it,
you
own
it.
@jschauma

48. You
break
it,
you
own
it.
You
fix
it,
you
own
it.
@jschauma

49. SoPware
maintenance
is
75%
of
total
cost
of
ownership.
OperaIonal
support
is
the
remaining
75%.
@jschauma

50. ParIcipate
in
Open
Source.
@jschauma

51. Mind
your
filter
bubbles.
@jschauma

52. Seek
diversity.
@jschauma

53. GitHub
is
(not)
your
resume.
@jschauma

54. Interviewing
is
bullshit.
@jschauma

55. Salary
negoIaIon
is
bullshit.
@jschauma

56. Salary
negoIaIon
is
bullshit.
Know
what
you’re
worth.
@jschauma

57. Your
first
salary
defines
future
salaries
for
this
career
path.
@jschauma

58. Your
first
job
does
not
define
your
career,
but
it
may
pidgeon-­‐hole
you.
@jschauma

59. There
is
no
such
thing
as
mulI-­‐tasking.
You
can
either
do
one
thing
well,
or
mulIple
things
poorly.
@jschauma

60. There
is
no
such
thing
as
mulI-­‐tasking.
Eliminate
distracIons.
@jschauma

61. “One
of
my
most
producCve
days
was
throwing
away
1,000
lines
of
code.”
@jschauma
-­‐-­‐
Ken
Thompson

62. Validate
all
your
input!
@jschauma
whitelist
>
blacklist

63. “Security”
can’t
be
added.
@jschauma

64. Your
endpoint
security
model
should
assume
the
network
is
compromised;
your
network
security
model
should
assume
the
endpoint
is.
Both
in
fact
are.
@jschauma

65. Always
use
UTC.
Use
an
unambiguous
format.
2016-­‐03-­‐02T14:22:33
03/02/16
2:22:33
@jschauma

66. @jschauma
https://xkcd.com/1597/

67. Fallacies
of
distributed
compuIng:
@jschauma
•
The
network
is
reliable.
•
Latency
is
zero.
•
Bandwidth
is
infinite.
•
The
network
is
secure.
•
Topology
doesn't
change.
•
There
is
one
administrator.
•
Transport
cost
is
zero.
•
The
network
is
homogeneous.

68. The
internet
is
awesome.
You
should
know
how
it
works.
@jschauma

69. Understand
the
DNS.
(Don’t
monkey
around
with
/etc/hosts.)
@jschauma

70. Know
tcpdump(1).
Be
able
to
read
a
pcap(3)
file.
@jschauma

71. @jschauma
Understand
the
OSI
stack.

72. The
internet
is
awesome.
You
can
help
keep
it
that
way.
You
can
help
make
it
awesomer.
@jschauma

73. The
internet
is
awesome.
You
should
help
keep
it
that
way.
You
should
help
make
it
awesomer.
@jschauma

74. @jschauma
Understand
the
OSI
stack.

75. Don’t
do
drugs.
Use
an
ad-­‐blocker.
Stay
in
school.
Disable
Flash.
Anonymity
is
important.
Yes
means
yes.
Don’t
get
phished.
Black
lives
maEer.
Use
a
password
manager.
Wear
sunscreen.
@jschauma