Blog: December 2022

Most of these posts were originally posted somewhere else and link to the originals. While this blog is not set up for comments, the original locations generally are, and I welcome comments there. Sorry for the inconvenience.

Online payments and credit cards

As I make the rounds doing year-end donations, I'm reminded of two things that have long puzzled me:

  1. Some web sites auto-detect the type of credit card based on the number. Apparently all credit-card numbers that begin with "4" are Visa. (I don't know if the reverse is true: do all Visa numbers start with 4?) Being me, I've cycled through the other nine digits and nothing else produces a match based on a single digit. What are the patterns for other providers? And are all these sites using some standard library for this, or are programmers really coding that by hand?

  2. Years ago, a three-digit code ("CCV") was added to cards to mitigate fraud. On a physical credit card, this number is stamped rather than embossed, so those old-style manual credit-card gadgets that took an imprint of your card (on actual paper, with a carbon!) couldn't record it. Um, that's fine I guess, but online, that number isn't any more secure than the card number itself. And someone who steals your physical card has the number; it's not a password. Does that number have another purpose?

Adventures in cat-sitting

A friend is traveling (with her housemate) and I offered to go feed her cat and give him some people-time each day. Her original flight was delayed to Sunday, so I made my first visit Monday morning.

It was 39 degrees in her house. The thermostat said it was holding at 60, but...no. I walked around the house checking for open or broken windows (none found). I went down to the basement and stared at the furnace -- no error codes or blinking lights, one steady light (so it had power), and that exhausted my knowledge of furnaces. I fed the cat, cycled through the thermostat programming to double-check things, reset the hold, built up some warm places to burrow, and tried to reach my friend (who was several timezones west of me, so I didn't expect an immediate response). I asked if she minded if I brought her cat to my house if we couldn't figure out the problem.

When she got my message she asked if the power was out (no, there were lights), and we speculated about whether power had gone out and come back on. I said I'd look for blinking or wrong clocks when I went back. Offhandedly, she wondered if a power outage would have somehow turned the thermostat off -- had I noticed if it was on? Um, I assumed it was because it showed me programming and let me set a hold temperature, and my thermostat doesn't let you do that if it's not on, and also it would be dangerously bad design if a power outage killed your post-power-resumption heat. So I went back later, and sure enough, the three-way toggle (cold - off - heat) was in the "off" position.

It's a physical switch, so I suspect my friend and the other person living in that house are going to have Conversations. Ouch. (Also, no blinking or very-wrong clocks.)

I turned on the heat and waited for the temperature to rise several degrees to make sure everything was on track. When I left last night the house was up to 45 degrees and the cat was very friendly. This morning everything was fine -- up to 65. (Yeah, maybe I overshot a little on that hold, but...)

Here's the scary part: originally they were going to leave on Friday, when the daytime high was 3F and the temperature was sub-zero before Shabbat started. When we were making the original plans, she'd said she'd feed the cat Friday so I didn't need to come until Saturday, and I said I wouldn't be able to come until Saturday night and that was fine with her. Friday night was frigid-cold here. I shudder to think what temperature the house would have been on my first visit if her flight hadn't been cancelled.

Standup meeting

Product manager: this resolved bug needs a severity.

Me (scrum master): would the product owner (that's a scrum role) and the developer who fixed it please handle that?

Developer: I am the product owner.

Me: I know. I assume it won't take the two of you(r roles) long to reach consensus.

Am I doing it right? :-)

Office check-in

Before the pandemic, I went to the office every day, as one does. Our office manager did what he could to make it an ok environment, but it has the usual pathologies. Pandemic-induced working from home has been good for me in oh so many ways. I'm fortunate to be at a point in my career where I am quite comfortable telling my employer "I really do insist". (There's some pressure, mild so far.) I'll go to the office if there's a specific reason to, like the group outing we had a few months ago, but most of the people I work with aren't local, so going to the office is social, not productive.

On the day of that outing, I learned -- via a coworker finding out the hard way -- that corporate security disables badges that haven't been used in 90 days. That makes sense, though doing it silently isn't so great. Fortunately for me, I last changed my domain password around the time of that outing, so the "time to change your password" reminder serves double duty.

A few days ago I changed my password, and today I went to the office to wave a badge at a sensor. While I was there I cleared out the last of my personal belongings; demonstrably, I no longer need to keep an umbrella or a spare USB charging cable in my desk drawer there.

Order matters

"I put the lemonade and limeade on the door next to the Coke."

"Is it Coke or Pepsi?"

"Uh, Pepsi."

"Ok, then that's the correct order."

Look, they're in unmarked bottles and almost the same color so I needed a way to tell, and alphabetical order is obviously the way to solve that problem, and why are you looking at me like that?

(If it had been Coke, I'd've asked him to swap; reverse-alphabetical would also be fine.)