Peter Seibel - Coders at Work - Reflections on the craft of programming

Looking at where we’ve come on the timeline of programming, we started with machine codes and then we took a leap to symbolic assembly language and then we took a leap to high-level languages and then we took a leap to structured programming and then we took a leap to object-oriented programming. And each of these leaps takes about a human generation.

We’re overdue on the next one. We’ve been at object for a while. You could argue it was Smalltalk-80. You could go back a little bit earlier, but we’ve been sitting on these ideas for a long time.

I think the next leap, we don’t know what the name of it is yet, but I think it’s something related to mash-ups where we can casually take bits of program and put them together and immediately make new programs. We’ve been talking for decades about a model of programming in which we snapped programs together like LEGO and make stuff. That hasn’t happened yet. But I think it is starting to happen now and the place it’s happening is in JavaScript, which is the least likely place.

Seibel:When you’re hiring programmers, how do you recognize the good ones?

Crockford:The approach I’ve taken now is to do a code reading. I invite the candidate to bring in a piece of code he’s really proud of and walk us through it.

Seibel:And what are you looking for?

Crockford:I’m looking for quality of presentation. I want to see what he thinks is something he’s proud of. I want to see evidence that in fact he is the author of the thing that he’s defending. I find that is much more effective than asking them to solve puzzles or trivia questions. I see all that kind of stuff as useless. But how effectively they can communicate, that’s a skill that I’m hiring for.

Seibel:Do you have any advice for self-taught programmers?

Crockford:Yeah, read a lot. There are good books out there. Find the good ones and read those. And if you’re doing web development, find the best sites and look at their code. Although I’m a little reluctant to give that advice yet. Most web developers learned to do web development by doing “view source,” and until fairly recently, most of the source that was out there was very bad. So you had a generation of programmers who were raised on really bad examples, thinking bad code was the way to write.

That’s getting better now, but there’s still so much bad stuff out there that I’m reluctant to give that advice yet.

Seibel:What about advice for someone who’s actually getting a C.S. degree who wants to work as a programmer?

Crockford:I would focus on the communication aspect. Learn to write; learn to read.

My advice to everybody is pretty much the same, to read and write. I generally don’t hire for specific skills. Until very recently, you couldn’t hire good JavaScript programmers. They were extremely rare. There are a lot of really good ones out there now, but that’s a fairly recent thing. So until that happened, I would just hire for quality. Are you a good Java programmer, a good C programmer, or whatever? I don’t care. I just want to know that you know how to put an algorithm together, you understand data structures, and you know how to document it. If you can do that, you should be able to figure out JavaScript.

Seibel:Have you ever had problems with that? People who’ve been successful in one language sometimes have a hard time giving up their old ways, even when working in a new language where they don’t really make sense.

Crockford:I have with, say, Windows programmers. Windows has a number of very complicated APIs and you can spend years just understanding how those APIs work. And that’s pretty much all you do, is you know that one API. You can write a window handle but there’s not much else you can do. I tend not to look for that kind of overspecialization unless I have a really specific niche. Generally, I prefer generalists. I want someone who’s capable of learning any of those APIs but isn’t necessarily skilled in any one.

Seibel:You said earlier that you got into computers because you thought they would make the world a better place.

Crockford:That’s my intention.

Seibel:How’s that working out?

Crockford:For the most part, we’ve done pretty good. I think the world is a better place, although it’s not always moving forward. Looking at, say, international politics over the last ten years, the consolidation of big media and the corrupting effects of that have not been compensated for by the open network. That’s a big disappointment.

Hundreds of thousands of people have died as a direct consequence of that. That’s really sad. I would like for the network to be doing a better job so that kind of stuff doesn’t happen again. It’s not clear yet what transformations to the network have to occur in order to accomplish that. And maybe it’ll be fine on its own, but I’m more pessimistic. I think we need to figure out the next leap in order to overcome whatever is not working now.

Seibel:Wouldn’t the gazillion bloggers out there say, “Hey, we’re out here blogging about everything and the mainstream media is taking it in the pants.”

Crockford:Yeah, that’s great. We still got it wrong. We’ve got this great thing where we can all get wired together and we can all get the message out to each other, but it’s not working. It’s just a lot of noise at this point.

Seibel:And do you think that part of that solution of that problem will be technical? Is there something programmers or system designers can do to tweak the architecture that will help? Or is it a social problem?

Crockford:It may be that new social systems have to evolve on top of this new network infrastructure and it’s just immature at this point and that’s why it’s not working. Maybe it just solves itself. I’m hoping that’s the case. But I think there may be more involved. Right now, the network does an extremely poor job of identity, does an extremely poor job of security, and those are a necessary component, I think, of building robust social systems. So that aspect of the Web is still deficient and maybe that’s why it’s so noisy still.

Creator of JavaScript, perhaps the most widely used and most reviled programming language on the modern Web, Brendan Eich is now CTO of the Mozilla Corporation, the subsidiary of the Mozilla Foundation responsible for continuing development of the Firefox browser.

With an appreciation of both elegant theory and good pragmatic engineering, Eich spent the early days of his career hacking network and kernel code at Silicon Graphics and MicroUnity. After MicroUnity, he moved to Netscape, where he worked on the Netscape browser and, under intense time pressure, invented JavaScript.

In 1998, along with Jamie Zawinski, he was one of the leaders of the effort to convince Netscape to open-source its browser, leading to the formation of mozilla.org, where he was chief architect.

In recent years Eich has been involved in both high-level direction setting for the Mozilla platform and in low-level hacking on a new JITing JavaScript virtual machine called TraceMonkey. And, as he explains in this interview, he has also been trying to find ways for the Mozilla project to “move the research needle,” bringing practical-minded academics into the Mozilla fold in order to bridge the gap between academic theory and industrial practice.

Other topics we touched on include why JavaScript had to look somewhat like Java but not too much, why JavaScript does still need to grow as a language despite the failure of the ECMAScript 4 project, and the need for more kinds of static code analysis.