Metail is a UK fashion technology startup with offices in Cambridge and London, UK. We use Clojure on the front-end and back and currently have vacancies for both Clojure and ClojureScript developers in our Cambridge office. If you’re interested in functional programming and are keen to work with Clojure, we’d love to hear from you. You don’t need to be an expert, we’re a friendly company and there are plenty of people here to help you learn and grow your skills.

Metail were early adopters of Clojure with the first code going into production back in 2010. This was a Clojure implementation of our size recommendation algorithm. Back then we were using Java’s Spring Framework for server-side applications, with the Clojure code embedded into the Spring application as a Java class. Nowadays, our web services are implemented in Clojure using Pedestal and ring-swagger and we are considering Lacinia for one of our newest applications. On the front-end, we use ClojureScript with re-frame and a Material UI library. We also use Clojure to orchestrate cloud deployments (REPL-Driven DevOps) and for large-scale data processing on Amazon’s Elastic Map Reduce clusters.

NonDysfunctional Programmers Meetup

William Byrd at Cambridge NonDysfuntional Programmers

Metail have long been supporters of the local tech community: I met CTO Jim Downing back in 2009, when he was running the local Clojure user group. I took over in 2013, and another Metailer, Rich Taylor, took up the reins this year. When Metail moved into a new city-centre office, we had space to host meet-ups ourselves, complete with data projector and excellent wi-fi. Now we are regular hosts of Cambridge NonDysfunctional Programmers, Data Insights Cambridge, Cambridge AWS User Group, DevOps Cambridge and Cambridge Gophers. As well as providing a free venue, Metail sponsors refreshments at many of these Meetups.

If you’d like to join this growing company and vibrant local tech community, check out our current vacancies. If you’re excited by the prospect of a Clojure career but don’t see your ideal job listed there, please drop us a line anyway – we’re always keen to hear from enthusiastic Clojure developers and there may an opening that hasn’t made it up to the website yet.


Most of the teams I’ve worked on have been not so great at breaking down the work that lands on the development backlog. There are plenty of resources out there on what stories are, and multiple different ways of writing them. There’s also articles written about different story splitting techniques. I couldn’t find anything out there about deliberately applying the theory however so I thought I’d write something.

Sometimes we just don't know how to begin breaking down work.

Before I dive in, lets start with some definitions

Epic – Also known as a “very big” story, that is unlikely to be completed in a single sprint or planning cycle. Would normally be broken down into several stories before being pulled onto a backlog. Epics can also be used for defining the main focus of a development team for a series of sprints.

Story – A smaller piece of work that can fit into a sprint or planning cycle specifically aimed at providing value to the end user and/or the customer. It can be good to apply the INVEST criteria to any story that you’re writing or at the very least include some acceptance criteria to define when a story is complete. Typically a story would be written in non-technical language to make it accessible for all interested parties to discuss. There are lots of different ways to write stories, Here’s a link to some sample formats.

Task – Pieces of a story that describe how the story is going to be achieved. These are usually written by the people doing the work. They should generally be short lived and completed within the sprint or planning cycle.

Splitting patterns

When examining a story (or an epic), you’re going to need to break it down. This has already been written about in much more detail over here. To keep things simple, I’ve summarized some of the commons ones:

  • Most difficult bit first (What’s the hardest piece of the story to solve?)
  • Simple case first (What’s the simple solution to the story?)
  • Functional first (Make it work, worry about performance later.)
  • User flow (What’s the first thing the user does. What’s after that?)
  • Per use case (What does user A want to achieve? User B?)
  • Per operation (buy a subscription, change a subscription, cancel a subscription)
  • Spike (What questions do you need to answer in order to know more about the solution?)

This is great! We now have some lines of thought we can use to think about our stories. We need to practice using these deliberately so as to get used to using them naturally and to ensure we don’t fall into the trap of using one or two of them over and over again.


Much in the same way as you’d practice different coding techniques in a coding kata, you can practice breaking down stories into tasks in a similar way. There is a little preparation to do in advance of your task break down kata.

Before you start, you’ll need to define some problems to split up. The problems should be large enough that they can be solved with multiple steps. Some examples might be:

  • Make a banana split
  • Go on holiday abroad
  • Buy something from an online store
  • Set up a new computer for a relative
  • Organize a party.

Try to work out if your problem is an epic or a story. If you’ve picked an epic, can you split it and write each story against the INVEST mnemonic? You want to end up with a few stories that can the broken down during the task break down kata.

Running the session

Split up in to groups of 2-3. Participants should be anyone that needs practice breaking down stories into tasks. If you can, try to make sure there is a mix of disciplines breaking down the selected story.

Choose a splitting pattern from above or from elsewhere, then take 10-15 minutes to apply the pattern to break down one of the stories. After you’ve applied the pattern, try to think around the edges and work out what was missed. What else needs to be included to make the story “complete”?

If you have lots of participants, compare and contrast results with other groups in the kata. Once you’re done you can try splitting the same problem again using a different pattern or use the same pattern on a different problem. Some problems will lend themselves better to one type of splitting pattern that others. Just keep practicing and you’ll get better at knowing which pattern to use for what kinds of problem.