The 'Just' Jar

date published : December 12, 2017 read time : 2 mins

Originally posted on

I thought I’d write a quick post to describe one of the little tweaks we recently made to our development process here at Airfinity.

Our dev team works in month long sprints at the moment and we generally take a day to estimate the top of the product backlog as a team, this is then used for a final re-shuffle of priorities by our product owner before we crack on and start building things. Of course things change over the course of the sprint, and we roll with that, the most useful information to facilitate this agility is reasonable estimations of size, complexity and duration.

One of the most common and dangerous words that I have heard when estimating or discussing software features, especially when discussing these with non-technical parties, is the word ‘just’.

Many articles have been written on this so I won’t bore you with why, if you build things you’ll know what the problem is, but for reference two good muses on the topic are here and here.

So to combat our use of the word we set up a swear jar*, or Just Jar^tm as we like to call it. Every time one** of our dev team uses the word just we cough up a pound, the proceeds of this will go towards extra drinks at our Christmas bash.

It’s a fun way to game behaviour and slowly change it, it helps us clarify our thoughts and think through estimation a little more to ensure we allow enough time, and it’s fun calling people out. Plus we have about £30 in the jar after our first month, so it’s pretty lucrative!

I suggest you give it a try, let me know what you think or how you get on in the comments.


*Obviously we still swear every now and then, the odd expletive is ok as long as it’s directed at your own code.

** Edit: I should point out that I am possibly one of the worst offenders/highest contributors, but hey you lead by doing right?