June 27, 2018

...Learn TDD with Codemanship

Team Craft

We're a funny old lot, software developers.

90% of us are working on legacy code 90% of the time, and yet I can only think of one book about working with legacy code that's been published in the last 20 years.

We spend between 50%-80% of our time reading code, and yet I can only think of a couple of books about writing code that's easier to understand that have ever been published.

We have a problem with our priorities, it would seem. And maybe none more so than in the tiny amount of focus we place on how we work together as teams to get shit done.

Our ability to work together, to communicate, to coordinate, to build shared undersanding and reach shared decisions and to make stuff happen - I call it Team Craft - rarely gets an airing in books, training courses and conferences.

In my TDD workshop, we play a little game called Evil FizzBuzz. If you've applied for a developer job in recent years, you may well have been asked to do the FizzBuzz coding exercise. It's a trivial problem - output a list of integers from 1 to 100, replace any that are divisible by 3 with "Fizz", any that are divisible by 5 with "Buzz", and any that are divisible by 3 and 5 with "FizzBuzz". Simple as peas.

I made it "evil" by splitting the rules up and requiring that individual pairs only work on code for their rule. (e.g., they can only work on generating a sequence from 1..100, or only on replacing numbers with Fizz, or Buzz etc).

They must coordinate their efforts to produce a single unified solution that passes my customer acceptance test - a complete comma-delimited sequence of the required length, with the numbers, the Fizzes, the Buzzes and FizzBuzzes in the right place. This is an exercise - superficially - in Continuous Integration. But, it turns out, it exercises far more than that.

An average developer can complete FizzBuzz in less than 30 minutes. An average team can't complete it in under an hour. No, seriously. 9 out of 10 teams who attempt it don't complete it. Go figure!

Watching teams attempt Evil FizzBuzz is fascinating. The first observation I've made - from dozens of teams who've tried it - is that the individual technical skills of the developers on the team appears to have little bearing on how they'll fare.

FizzBuzz is easy. It doesn't require strong Code Fu. And yet, somehow, it defeats 90% of teams. There must be something else at play here; some other skillset outside of coding and unit testing and refactoring and Git and wotnot that determines how a team will perform.

Over the years since it was introduced, I've developed an instinct for which teams will crack it. I can usually tell within the first 10 minutes if they're going to complete Evil FizzBuzz within the hour, just by looking at the way they interact.

Here are the most typical kinds of rocks I've seen teams' ships dashed on trying to complete Evil FizzBuzz.

1. Indecision - 45 minutes in and the team is still debating options. Should we do it in Java or JavaScript? Jenkins or TeamCity? NUnit or xUnit.net? Making affirmative decisions as a group is a hard skill. But it can be learned. There are various models for group decision making - from a show of hands to time-boxed A/B experiments to flipping a coin. I maintain that the essence of agility is that ability to make effective decisions quickly and cheaply and move on.

2. Priorities - the team spends 30 minutes discussing the design, and then someone starts to think about setting up the GitHub repository and a CI server.

3. Forgetting They're In a Team - I see this one a lot. For example, someone sets up a repository, then forgets to invite the rest of the team to contribute to it. Or - and this is my favourite - someone writes their code in a totally different set of project files, only realising too late that their bit isn't included in the end product. To coordinate efforts in such a small solution space, developers need to be hyper-aware of what the rest of the team are doing.

4. Trying To Win The Argument Instead Of The Game - as with 1-3, this is also very common on development teams. We get bogged down in trying to "win" the debate about what language we should use or whether we should use the Chain of Responsibility design pattern or go for tabs or spaces, and completely lose sight of what we're setting to achieve in the first place. This effect seems to escalate the more technically strong individuals on the team are. Teams of very senior developers or software architects tend to crash and burn more frequently than teams of average developers. We've kind of made this rod for our own backs, as a profession. Career advancement tends to rely more on winning arguments than achieving business goals. Sadly, life's like that. Just look at the people who end up in boardrooms or in government: prepared for leadership in the debating societies of our top schools and colleges. Organisations where that isn't part of the culture tend to do much better at Evil FizzBuzz.

5. All Talk, No Code, No Pictures - the more successful teams get around a whiteboard and visualise what they're going to do. They build a better shared understanding, sooner. The teams who stand around in a circle talking about it invariably end up with every pair walking away with a different understanding, leading to the inevitable car crash at the end. It's especially important for each pair to understand how their part fits in with the whole. The teams that do best tend to agree quickly on how the parts will interact. I've known this for years: the key to scaling up development is figuring out the contracts early. Use of stubs and mocks can help turn this into an explicit executable understanding. Also, plugging their laptops into the projector and demonstrating what they intend is always an option - but one that few teams take up. To date, no team has figured out that Mob Programming is allowed by the rules of the exercise, but a couple of teams came close in their use of the available technology in the room.

6. Focus On Plans, Not Goals - It all seems to be on track; with 5 minutes to go the team are merging their respective parts, only to discover at the very last minute that they haven't solved the problem I set them. Because they weren't setting out to. They came up with a plan, and focused on executing that plan. The teams that crack it tend to revisit the goals continually throughout the exercise. Does this work? Does this work? Does this work? Equally, teams who get 30 minutes in and don't realise they've used 50% of their time show a lack of focus on getting the job done. I announce the time throughout, to try and make them aware. But I suspect often - when they've got their heads down coding and are buried in the plan - they don't hear me. The teams who set themselves milestones - e.g. by 20 minutes we should have a GitHub repository with everyone contributing and a CI server showing a green build so we can start pushing - tend to do especially well.

From long experience on real teams, I've observed relationships between these elements of Team Craft. Teams that lack clear objectives tend to consume themselves with internal debate and "pissing contests". It also tends to make prioritising nigh-on impossible. Tabs vs spaces matters a lot more when you think you have infinite time to debate it. Lack of visualisation of what we're going to do - or attempt to do - tends to lead to less awareness of the team, and less effective coordination. And all of these factors combined tend to lead to an inability to make shared decisions when they're needed.

But before you conclude from this that the individual technical skills don't matter, I need to tell you about the final rule of Evil FizzBuzz: once the build goes green for the first time, it must not go red again. Breaking the build means disqualification. (Hey, it's an exercise in Continuous Integration...)

A few teams get dashed on those rocks, and the lesson from that is that technical discipline does matter. How we work together as teams is crucial, but potentially all for nought if we don't take good care of the fundamentals.

Posted 2 weeks, 5 days ago on June 27, 2018