Start In The Middle

I start in the middle of a sentence and move both directions at once.
— John Coltrane

Newspaper reporters are taught to write fractal articles: summarize the entire article in the title. Elaborate a little in the first sentence, then fill out the most important details in the first paragraph. A reader should be able to stop at any point without having missed any important details. We should approach programming projects in the same way.

As a child – after some experimentation and a lot of thought – I decided the best way to eat cornflakes was as follows:

Cornflakes, by Mike Haufe

1. Pour the cool milk over the golden roasted flakes
2. Sprinkle the one allowed teaspoon of sugar over the top
3. Start eating around the edges, saving the sugary middle section for one last big spoonful of joy at the end

I stand by that decision. In fact, I’ve noticed I do similar things in other areas of my life. I’m sure a psychologist would talk for hours on the subject. Luckily for you I’m not a psychologist, I’m a programmer. And it turns out that this is an awful way to work on software projects.

Has this ever happened to you? You wake up one day with a great new idea for applying bayesian filtering to twitter streams to filter out the pictures of Joel’s new puppy spam. You’re totally convinced it’s what the world needs. It’s the startup that’s finally going to help you to break out of your day job maintaining PHP payroll software stock supermarket shelf stockers. So what do you do? You do this:

1. Fire up your IDE and start a new website project
2. Whip up a login page and get the user account basics set up
3. Decide OpenID’s really where it’s at these days and hit stackoverflow for a good OpenID provider plugin
4. Run into problems getting it to accept Google accounts and spend half the night debugging it

Wait, what? How did this happen? Getting OpenID working isn’t fun. It’s almost the definition of not fun.

I didn’t want to do all this, I just wanted to make an awesome bayesian twitter filter, but somehow there’s all this stuff I have to get through first.
— Me (swear words redacted)

My hard disk is littered with projects that I started, got half way through setting up without ever really getting to the good bit, then abandoned. I suspect yours is, too.

The right way to start a bayesian twitter filter is to apply a bayesian filter to content from a twitter stream. I know. It looks like this:

1. Google for some bayesian filter code
2. Dump whatever’s in your twitter client logs to a file and write three lines of python to parse it into a form the bayesian filter can work with
3. Train the filter and see what happens

Compared to the original approach it looks awesome, right? So what stops us approaching all projects like this? Well, there’s something beguiling about wanting to get the framework right from the start this time. It’s more comfortable starting with something we already know how to solve. Sometimes we have a clear vision of how it should end up in our heads and simply start to create that vision from the beginning through to the end.

Start in the middle
— Paul Graham (lightly paraphrased)

Lean startups and the Minimum Viable Product are all about starting in the middle. Paul Graham’s advice for startups can be summed up as ‘first solve the interesting part of the problem, then build the business around it’, but the process is also fractal – starting in the middle applies right down to the level of writing a new class, or a single function. First write some code that solves the problem even if it’s imperfect or partial, then expand it out with your favourite blend of accessors, inheritance and polymorphism (Note: don’t even bother with that bit unless you hate yourself).

I’ve seen four key benefits to starting in the middle:

Benefit 1: Ideas that turn out to be impossible or just plain bad are discovered early. This is classic lean startup advice: fail early.
Benefit 2: Spend most of your the time solving interesting problems and not fine-tuning framework skills. Which would you rather get better at?
Benefit 3: Discover interesting things while your project is still young and flexible enough to adapt to them.
Benefit 4: Once you’ve solved a problem, you’re so motivated to use it that you finish up the surrounding areas in no time. You add extra users because you want to show it to your friends; you add keyboard shortcuts because you’re getting tired of using the mouse all the time. This is programming the right way around – first the need, the desire, and then the solution.

I’ve recently seen all of these benefits while working on my own side-project-turned-startup. Ages ago I had this great little idea for making profiling so simple that it just told you which line of code was slowest in a nice little report and I whipped up some C# code to do just that. The results weren’t making much sense, so I tried plotting the data to a canvas to see what was going on. Pretty soon I was looking at a poor man’s sketch of this:

Visualizing a program's execution

Instantly I knew I’d been working on the wrong thing; seeing the execution of a program laid out before me in all its glory was so rich and so interesting; something I had no hope of summarizing in a small table of figures. I just had to explore it – I added function names, colour, a breakdown of time spent in each and over time it grew into such a valuable part of my toolkit that I’ve started sharing it with the rest of the world.

Would I have changed direction if I had already created a website, a login system, a messaging layer, a database schema all geared around the original idea? No. I’d have reached the interesting part of the problem with a half-finished framework and close to zero energy and enthusiasm. The discouragement at seeing the futility of my cherished profiling-via-pdf idea would’ve seen me put the whole thing back on the shelf and go play Altitude to forget about it.

So start in the middle, start with the interesting, challenging, core of the problem you’re trying to solve. Cut down everything else to ridiculous minima and see what happens; you may create something fascinating.

Note: Yield Thought has moved to http://yieldthought.com – check there for the latest posts!