Friday, 14 September 2012

The Next Innovation

Here's a little comic strip I put together ...

When you have created so many innovative products, it's always going to be difficult to come up with enough differentiation between one version of a product and the next to keep getting people to spend their cash. Creating an entirely new product line is even more of a challenge. I'm wondering where our favourite fruit named company is going to go next.

Tuesday, 17 July 2012

Unit Testing with MongoDB

Back in June I presented at the London Scala User Group (video here) on our experiences on a recent Scala project that used MongoDB.

One of the questions I was asked was how we go about mocking MongoDB for testing purposes (especially unit testing)? My answer was that we don’t! This raised a couple of eyebrows in the audience, but we’ve found this works just fine for us.

In this blog post I will explore our thoughts and reasoning in a bit more detail.

How do we test with MongoDB?

I’ll be honest: for the majority of our tests (even the unit ones) we just run against a local MongoDB instance. When we are testing repository classes we write tests against a real repository wired up against a real MongoDB instance. We assert against the contents in the MongoDB collections. In some cases, we even test service classes or even controllers with a live repository backend that writes to and retrieves from a real MongoDB instance.

“But you can’t do that!”, I hear you cry. Traditional thinking says that writing tests directly against the database will be too slow. We’ve actually found MongoDB (especially when running locally) to be so blindingly fast that we don’t need to consider doing anything else. For most updates and queries we tend to get sub-millisecond responses.

It’s also a hell of a lot easier and less fragile to back tests with real repository instances than it is to create and configure a load of mocks or strange database testing frameworks.

I’m pragmatic. If using a real database backend was making our tests run too slow or causing them to be too complex then I’d happily consider alternatives. Our experience with MongoDB is that it is both fast enough and that it’s query syntax is succinct enough that we don’t need to bother with those alternatives.

Do we use mocks at all for the database then?

Actually, I rarely use mocks in any of my Scala project now days. I’ve switched much more towards a style of isolating my calls to dependencies and then using mixin traits to override specific behavior for testing. (I’ll write a blog post about this approach soon).

From time to time we do need to write tests that make a repository dependency exhibit a specific behavior which is difficult to emulate against an actual database. In these cases we just use a custom test trait mixed into the repository in order to override methods to exhibit the behavior that we require. Keeps it simple and makes the tests much more readable and much less fragile than using mocks or other frameworks.

Thursday, 12 July 2012

Making Agile Go Fast

Just recently I was speaking with a potential customer who had concerns about the velocity of their Scrum teams. They had recently (9 months ago) switched to an agile approach and had expected to get much more delivered than they had.

Now they were looking in to scaling up the number of Scrum teams on the project to try and increase velocity and deliver more quickly. In my experience of many agile projects, increasing the number of people on the project, especially one that is struggling, never has the desired effect of making things go faster. The advice to this customer was to therefore look at making their existing teams and process more effective rather than increasing the number of people on the project.

This got me thinking about what makes agile projects go slow. Across a number of projects that I have experienced, I’ve identified four common traits: two related to people and process and two related to technical concerns.

The Wrong People

Agile is all about using the right people. In fact this is true for any project or process, but for agile it is even more important. Use the right people and the agile process will work. Use the wrong ones and you will struggle.

The people who you don’t want on your agile project are those who are not disciplined enough to follow sound engineering practices and those who try to build complex frameworks/toolkits and who conduct personal science projects on your codebase. If you want to go fast then it’s vital that you have a clean, simple and well-refactored codebase that is backed up by a set of quality tests. Team members who don’t support this vision slow down the whole team.

To get back on track, remove those devs who aren’t following good engineering discipline and those who keep making things more complex. Bring in experienced agile developers to pair with the remaining team, giving them the responsibility of ensuring quality engineering practices are followed.

Putting The Process First

Another common mistake of companies starting out with agile projects is that they assume the process will make them go faster. Sorry to disappoint, but this is just not true. What makes agile teams go fast is creating open channels of communication and self organising and empowered teams.

If an organisation can’t create an excellent environment for communicating then no agile process will help. Agile helps teams go faster by eliminating the unnecessary documentation and waterfall steps. However, this information transfer must still happen and it happens through closer communication and collaboration.

Sadly, many organisations create agile teams and give them a process to follow but then insist on telling them how to organise, what tools and techniques to use, how to work and exactly what to do. This isn’t agile, it’s just another way of organising a traditional team. If you want agile to go fast then the team need total control over how they work and what they do.

To get back on track from here, relax on the process. Work on increasing communications. Give the agile teams the chance to decide how they will organise and work. Give them control and they will go faster. Agile is not a process, it’s about letting people get the job done.

Using The Wrong Technologies

So many agile projects struggle because they are using the wrong technologies. When this is the case it’s usually because the technology approach has been foisted on the team by an ‘ivory-tower’ architect or some senior manager who was wooed by the sales consultant from a large vendor. In other cases it may be that the team are forced into using a ‘corporate standard’ technology set.

In many cases the team will repeatedly identify the technology as a major factor in retrospectives. However, more often than not they will be told that this is not something that can be changed and that they have to stick with it. Why throw away hundreds of thousands or even millions on staff costs when backtracking on some poor technology choices would make so much difference.

Again, giving the teams the authority to make technology decisions is essential. Allowing technology choices to be reversed if they prove to be hindering delivery is also an important part of being agile.

Making The Architecture Too Complex

Many software systems are designed, or become, far too complex. In an agile environment this is a guaranteed way of making things go slower. Software must be kept as simple as possible so that it is easy to continually change and enhance.

If the architecture of an agile system has become so complex that it hinders development then it must be revisited and greatly simplified. Layers must be removed, interfaces reduced and code and technologies radically refactored to make everything simpler. Once that is done then the project must work all out on stopping it from getting more complex again in the future.


Only by using the right people, correctly empowered and communicating can the team have the ability to go fast and be truly agile. Only by making the correct technology choices, reversing bad technology choices and keeping everything simple can the ability to turned into real agile delivery.

Friday, 22 June 2012

Cucumber JVM Support for SBT

I am happy to announce release 0.5.0 of my xsbt plugin for cucumber. This is a major new update that finally switches from using the Ruby version of Cucumber (running under JRuby) to the newly released Cucumber-JVM.

Full details of how to use the plugin can be found on the github page: https://github.com/skipoleschris/xsbt-cucumber-plugin

A list of significant changes for this release include:

  • Switched to cucumber-jvm
  • Less configuration options due to no longer requiring JRuby
  • Improved control of output options

Sunday, 10 June 2012

Pairing is Wearing

In this post back in August 2011 I was talking about the many benefits of Pair Programming. Having now been full-time pair programming for almost an entire year, I wanted to mention one of the downsides that I have discovered.

A Holiday

I've just finished my holiday. It wasn't the best one ever, mainly due to camping in the UK in June: which meant heavy rain and strong winds. Still, we had a good time and it was very relaxing.

As the week progressed and I had a chance to relax, unwind and get some lie-ins I started to discover that my mind was starting to become more alert. I was feeling less tired. Great ideas were starting to flow again. It was at this point I realised just how weary I had been at the start of the holiday. I had known I was feeling pretty knackered, just not quite how much.

This then got me thinking as the the possible cause of this tiredness and how it could gradually build up over time without me being fully aware of it. I looked back at what I've been doing for the past year...

  • I've been travelling a lot to get to/from work - but less than my previous job.
  • I've been learning lots of new stuff - but I'm a compulsive learner, so nothing new here.
  • We've put at least 3 major releases live - but I've put plenty of software live before.
  • We've been pairing full time - this is new!

Is Pairing More Tiring?

The conclusions that I have had to draw is that working in a paired environment is more mentally tiring that working alone or individually within a team. There's more of a requirement to stay focused when working as a pair - it's particularly noticable when one member of the pair is feeling unwell or tired. Also while pairing you are multitasking more - writing code, thinking about solutions but also communicating your thoughts and maintaining a running dialogue. All of this extra work requires extra mental energy and thus increases fatigue.

So, how can we pair over a period of time without burning out? Here's some thoughts that I hope to experiment with over the coming months:

  • Take more frequent and longer breaks than you would do while working individually. The productivity gain of working in pairs easily allows this to be supported
  • Do a lot more walking at lunchtime!
  • Try to provide team members regular tasks that they can undertake outside of a pair to give their mental energy drain a rest. Stuff that doesn't require extensive multitasking.

Anyone else got any thoughts or ideas?