Kleyguerth was having a hard time tracking down a bug. A _hasPicked flag was "magically" toggling itself to on. It was a bug introduced in a recent commit, but the commit in question was thousands of lines, and had the helpful comment "Fixed some stuff during the tests".

In several places, the TypeScript code checks a property like so:

Calendars today may be controlled by a standards body, but that's hardly an inherent fact of timekeeping. Dates and times are arbitrary and we structure them to our convenience.

If we rewind to ancient Rome, you had the role of Pontifex Maximus. This was the religious leader of Rome, and since honoring the correct feasts and festivals at the right time was part of the job, it was also the standards body which kept the calendar. It was, ostensibly, not a political position, but there was also no rule that an aspiring politician couldn't hold both that post and a political post, like consul. This was a loophole Julius Caesar ruthlessly exploited; if his political opposition wanted to have an important meeting on a given day, whoops! The signs and portents tell us that we need to have a festival and no work should be done!

A ticket came in marked urgent. When users were entering data in the header field, the spaces they were putting in kept getting mangled. This was in production, and had been in production for sometime.

Mike P picked up the ticket, and was able to track down the problem to a file called Strings.java. Yes, at some point, someone wrote a bunch of string helper functions and jammed them into a package. Of course, many of the functions were re-implementations of existing functions: reinvented wheels, now available in square.

We're going to start with the code, and then talk about it. You've seen it before, you know the chorus: bad date handling:

C_DATE($1)
C_STRING(7;$0)
C_STRING(3;$currentMonth)
C_STRING(2;$currentDay;$currentYear)
C_INTEGER($month)

$currentDay:=String(Day of($1))
$currentDay:=Change string("00";$currentDay;3-Length($currentDay))
$month:=Month of($1)
Case of

: ($month=1)
$currentMonth:="JAN"

: ($month=2)
$currentMonth:="FEB"

: ($month=3)
$currentMonth:="MAR"

: ($month=4)
$currentMonth:="APR"

: ($month=5)
$currentMonth:="MAY"

: ($month=6)
$currentMonth:="JUN"

: ($month=7)
$currentMonth:="JUL"

: ($month=8)
$currentMonth:="AUG"

: ($month=9)
$currentMonth:="SEP"

: ($month=10)
$currentMonth:="OCT"

: ($month=11)
$currentMonth:="NOV"

: ($month=12)
$currentMonth:="DEC"

End case

$currentYear:=Substring(String(Year of($1));3;2)

$0:=$currentDay+$currentMonth+$currentYear

Chris's company has an unusual deployment. They had a MySQL database hosted on Cloud Provider A. They hired a web development company, which wanted to host their website on Cloud Provider B. Someone said, "Yeah, this makes sense," and wrote the web dev company a sizable check. They app was built, tested, and released, and everyone was happy.

Everyone was happy until the first bills came in. They expected the data load for the entire month to be in the gigabytes range, based on their userbase and expected workloads. But for some reason, the data transfer was many terabytes, blowing up their operational budget for the year in a single month.

Guy picked up a bug ticket. There was a Hiesenbug; sometimes, saving a new entry in the application resulted in a duplicate primary key error, which should never happen.

The error was in the message-bus implementation someone else at the company had inner-platformed together, and it didn't take long to understand why it failed.