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Programmers, Teach Non-Geeks The True Cost of Interruptions

Interruptions are one of the biggest sources of inefficiency for programmers. Now, to be fair, they’re probably a big source of inefficiency for everyone, but relatively speaking, they’re worse for programmers. To understand what I mean, let’s take someone whose job is in sales. A lot of the day is probably spent on the phone or in transit to and from meetings. In a given meeting or while reviewing notes prior to a meeting, an interruption to a sales person means time spent dealing with the interruption, a shake of the head, and a “where was I… oh, right.” For a manager, the day is often just a series of never-ending interruptions. In a management capacity, I find it common to sit down at lunch, still not having done the first thing I planned to do that day. Paul Graham has an excellent article about the different natures of the day for managers and for people he calls “makers,” a group that clearly includes programmers.

For a programmer, an interruption is oh-so different. There you sit, 12 calls into the call stack. On one monitor is a carefully picked set of inputs to a complex form that was responsible for generating the issue and on the other monitor is the comforting dark theme of your IDE, with the current line in the debugger glowing an angry yellow. You’ve been building to this moment for 50 minutes — you finally typed in the right inputs, understood the sequence in which the events had been fired, and got past the exact right number of foreach and while loops that took a few minutes each to process, and set your breakpoint before the exception was triggered, whipping you into some handler on the complete other end of the code base. Right now, at this exact moment, you understand why there are 22 items in the Orders collection, you know what the exact value of _underbilledCustomerCount is and you’ve hastily scribbled down the string “8xZ204330Kd” because that was the auto-generated confirmation code resulting from some combination of random numbers and GUIDs that you don’t understand and don’t want to understand because you just need to know what it is. This is the moment where you’re completely amped up because you’re about to unlock the mysteries of what on earth could be triggering a null reference exception in this third party library call that you’re pretty sure —

“HI!!! How’s it going? So, listen, you know that customer order crashing thing is, like, bad, right? Any chance I can get an ETA on having that fixed?”

Interrupted

DAMNIT!!!!

The project manager just startled you while you were getting ready to hit the next instruction and you hit “step over” instead of “step into!” He’s droning on and on about the importance of himself or the customer or something that you’re not listening to because you’re trying to control your rage at having lost all of your debugging context while also starting to think ahead to how you can get back to the point you were at in maybe 30 minutes instead of 50. But it’s no use. PM’s boss sees PM talking to you, walks over, and now there’s a full-blown discussion about the Initrode account going on next to your desk, loudly, complete with ridiculous buzzword BS bingo and sports metaphors about “closing out the game in the endzone” or something. By the time the dust settles and you’ve been Six-Sigma-ed into submission by 3rd degree black belts, you know that you’re going to be ordering a pizza and doing this again at 7 PM after everyone else leaves so that you can have some peace and quiet to work. All you can do is shake your head in sad disgust and wonder, “what on earth does 8xZ204330Kd mean and why did I write that down?”

But here’s the real insult-to-injury moment. When you try to explain to the PM how insanely destructive to your productivity that interaction was, he snorts at you and tells you not to be so melodramatic. He wanders off, wondering why programmers are such overdramatic prima donnas. Your non-techie peers just don’t get it, no matter how many times you try to make them understand. When part of your job is walking around all day demanding status updates and having the same demanded of you, it’s easy not to understand how different the programmer’s work paradigm is. I’ve been on both sides of it, and now that I spend a good portion of my day doing planning and overhead activities, I have to fight the impulse to drop by the area where my team sits and interrupt them regularly to get a piece of information so that I can put it in some email or add it to a list of resolved issues. PMs, managers, etc. all have real problems, many of which involve attempting to provide timely support to partners, clients, or internal staff, and issues and problems are interruptive, by their very nature.

Well, worry not, because I think I have a way that you can actually demonstrate to them just how devastating interruptions are to your productivity compared to, say, theirs. In other words, here’s how to make someone understand that, for you, an interruption isn’t just a delay after which you can get right back to work but a complete total of your efforts up to that point. Here’s how.

Invite the PM/manager/sales/whatever person to sit at his desk and tell him to humor you. Open up notepad and type a series of 3 or 4 digit numbers in sequence, like so:

123
234
345
543
432
321
999
888
777

Now, tell him to add those numbers in his head. He can look at the screen and talk/whisper/mutter to himself, but he can’t write anything down and he can’t type anything. He may laugh. Tell him that you bet him lunch he can’t get it done in five minutes, only getting one shot at getting the answer right. Maybe he’ll stop laughing and get to work.

Sit down, curl your hands behind your head and give him half a minute or so. Listen to him muttering. Then, get out your cell phone and call his office line. If he ignores it, ask him if he’s planning to answer it, since it could be important. He’ll grunt and mumble something about having to start over.

Give him another 30 seconds or so and say, “So, harder than you thought, huh? Which number are you on? You know which number always gets me? 333. Something about that number. Or maybe it’s 221. Or anything that adds to 9,365. Numbers, amirite! Oh, crap, sorry, you were concentrating. I’ll be quiet.”

Give him a minute. Pull out your phone and start talking loudly to no one on the other end, simulating a call. Start reciting imaginary phone numbers. Look sheepish and apologize.

Give him another minute. Blurt out that you’re low on work today, and ask him if he still wants you to add those three things about the four or five other things to six or seven of the upcoming performance presentation slides, and, oh, geez, numbers again, your bad.

Give him yet another minute. Then tell him that he’s only got 20 seconds left. Or is it 30? Maybe 25. Whatever the case may be, he’s getting into crunch time. Oh well, you guess he failed. Thank him in advance for lunch, but offer to let him keep his lunch money if he promises to stop constantly doing what you just did to him while you’re trying to code, which is a lot like keeping track of numbers all day in your head.