Sunday, August 1, 2010

Can you do it? A simple web app, start to finish in one week

It's useful in life to set challenging, yet achievable goals. After some recent setbacks I decided to recover my ego with this simple task: given a good, simple idea for a useful web app, go from idea to launch in one week.

I'm happy to say that I completed this goal. The result is: http://www.dotcomroulette.com/

Was this challenging? Of course. I intended to still do all the normal things I need to do during the week, like going to the gym and going to grocery store, and use up extra time that I would have spent puttering around doing nothing of use. I was largely able to accomplish this, but I did stay up late a couple nights. I counted two Wednesdays as one day and found bugs over the next few days, but sometimes you have to make success fit you rather that you fit success.

Several times I was set back my an unexpected obstacle by at least a day. The worst of these was WHOIS. My site is powered by Google App Engine. GAE is ideal in many ways but sandboxes you into a limited environment where the only network calls you can make are over HTTP. I had expected that someone had written some HTTP whois API that I could call to make queries. Instead I had difficulty finding any, and those that did exist were not reasonably priced for my needs since I had to make hundreds of whois queries for each name suggestion (so $0.01 per query is not going to be profitable for me, to say the least).

I ended up writing a threaded HTTP-WHOIS proxy server that I run somewhere else. This is a significant design limitation, since if it goes down the entire site is unusable. Given that both systems are uncorrelated this means of course a multiplicative increase in the failure odds (p(fail) = 1 - (p1(fail) * p2(fail)). It's also a single ugly bottleneck for all those clouded GAE instances out there, sort of defeating the point.

The frontend design also took at least 40% of the time. Design is not one of my strengths and this component of creating the site was a source of anxiety for me. Would I be able to make something passable in a short period of time? I ended up coming up with some that I liked, but it wasn't something that I felt 100% confident about in advance of doing it.

UI-wise I found that I had to rule out doing anything ambitious that I didn't more or less know how to do already in the interest of releasing quickly.

The algorithm was easy. I had this down in a couple hours. Including writing the entire bayes and markov engines from scratch. Goes to show how well I know this stuff now. I later went back and optimized it, for instance, by replacing lists of numbers with python's optimized array.array data structure.

I also cut several features that I felt 1) complicated the layout, forcing me to make decisions about the layout that I wasn't certain about making and would have fretted over endlessly, and 2) didn't add that much value at launch time. For instance, I wanted to have a sidebar that would pull in retweets from the twitter api. Sometimes it's kind of hard to think of key words when you're staring at the input box and I wanted a way for people to get ideas using examples that others had shared. Additionally people could get a little feedback reward from doing a retweet, which gives me the obvious benefit of getting exposure to that person's twitter followers. But I couldn't make up my mind as to where I would put that element so that it wouldn't be distracting for people looking at the page for the first time and I couldn't even test the feature because twitter apparently couldn't even index the .appspot.com name for the site. In the interest of getting a release out the door, I cut the feature.

What did I learn?

I learned that I can make a genuinely useful web app in a week.

What if I could do this every week?