Optimization

Tonight it hit me, as I was giving advice, that I was dispensing wisdom I would do well to listen to myself. It was a question about optimization. Whenever you use that word, you have to know what you are optimizing for. Sometimes I forget.

One of the approximations of social media I engage in is a place called StackOverflow.com. That site and dozens of its sisters are an indispensable resource for programmers and tech folk in general. Some nights, like tonight, when I’m a little adrift, I will stop by over there and see if there are any questions pending I am qualified to answer.

When you’ve been around a while, you realize that there are almost no new questions, and in the major categories there are semi-pro question-answerers who can swiftly point the new question to the ancient answer. For php, you will see the name Barmar time and again, always helpful, always gentle.

But there is a category of question that in general is found to be annoying on Stack Overflow, but that I can answer well. These are questions that go beyond the nuts-and-bolts of a language to get to the heart of what programming really is. I will see the code they post, often a mess, and I can sort through it and figure out what is the actual question.

While others will downvote the question for being a mess, I find an opportunity to teach. I see someone who, with a little help, will see the mess also. My answers are long, and meticulous, but if I feel like I’m answering a homework question I leave out the key stones in the path.

A recent example: Someone had code that took the result of a database query and built an html table. But the result of the query didn’t directly match what was to go into the table. So while drawing the table, the code was also trying to figure shit out.

I suggested that while there was no way I was going to figure out what was wrong with the code as written, I had a simple concept to apply: Think, then Draw. Get all the information set up beforehand so that creating the html was just a brain-dead loop.

I have discovered that I have axioms. One is “Keep the guards close to the gate.” Another, apparently, is “Think, then draw.”

Tonight I came across a question asking for how to optimize a data manipulation operation. Massive data in, then a rearrangement of the data to be more useful later. The code to accomplish the data transform included nested loops, but was pretty tight and pretty clean. “How do I optimize this?” was the question.

I have come to realize that optimization of code is an economic judgement, not a technical one. The most obvious tradeoff: You can use more memory to make your process run faster.

But there is another, more subtle, economic tradeoff. Tonight I answered the optimization question with another economic argument: that Engineer Hours are worth more then CPU milliseconds. I told that person that if their code worked, and there wasn’t a specific problem caused by it, then it was perfect and they should move on to the next problem. I told that programmer to value their own time. Not just for personal reasons, but to better judge how their time could best help their endeavor.

Value your time, but also recognize the cost of your time.

My friends, this is something I do not do well. Where I work, I am moving our stuff from an environment where it was hosted for free, to a place where we will have to pay for the resources. I am, at heart, a cheap bastard. While that does me well at the poker table, it may not always serve the interests of my employer. I am constantly aware that all resources I request will now be billed.

So I spend time, hours of my time, trying to guess how small a footprint I can squeeze into on behalf of our group. I spend hours on elaborate schemes to do more with less. But I am not serving my clients well. I’m not including the cost of my time in the value equation. Things are too slow? I could spend a week doing clever stuff, at a cost to my company of thousands of dollars in my compensation while I defer projects that actually will make things run better, or I could just submit a form and get more RAM for the database, at an incremental cost for the department each month.

In my defense, I HATE filling out forms. I HATE the call that comes after while someone else re-enters the form into a different system, and invariably makes a mistake. I will take a week with the code over an afternoon of nonsense any time. But that is a weakness, not a strength. That is me allowing my own preferences to make decisions that are not properly optimized.

I am, at heart, a person who can take a problem and slice it and slice it and slice it until each part is a simple question, and I can take the answers to those questions and combine them to arrive at the solution. While I’m at it, I’ll make tests so that each part proves itself. When you see my code at the flea market, it will be on the shelf behind the table, where you will have to ask to get a closer look. I am proud of this. But it is not always a good thing.

There was a time I was VP of Software Engineering at a small company, and I did all right in that role. During the dot-com boom I held a pretty dang good team together. I didn’t have to fill out forms then, either. We were all just building something awesome. The calculus of the value of my time was different then; Engineer-hours — my hours — were a commodity; the value only to be realized if the venture succeeded. (Picture Facebook, before Facebook, only far more dynamic, with the fatal flaw of being private.)

Good times, good times. The sleep-optional days of youth. But if I’m going to justify that little walk in the past in this ramble, I have to tie it to the present.

Back then, I was paid well enough but there was never doubt that Engineer Hours were the currency we were paying to make our name. Our data center was a few racks in a room that had once been a bank vault (AWS was decades away yet). Everything, everything, was optimized for minimum CPU.

Tonight, while I was (very gracefully I’m sure) reminding a young coder about the relative value of CPU cycles relative to neuron flashes, I realized that I have not been very good at making that judgement myself. I need to do better. Not just for my team, but for myself. I need to fill out the goddam form, bluster my way to 4x the resources I actually think we need (magnificently tiny, in the scale of my company), and recognize that my time is better spent making new things, rather than helping the old things go.

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