There are many difficulties related to solution development. One of the key stumbling blocks for many of us is the tendency to focus on the solution before we properly understand the problem.

For me (and many other people smarter than me) a critical tool to overcome this tendency is the Domain Model. When done correctly, a domain model enables us to focus our attention squarely on the problem domain - ensuring we understand the concepts at play, their interrelationships, and the terminology used.

Of course there are many other tools in our toolbox as analysts, and we'll start using many of them in the coming weeks, but I generally find myself reaching towards the domain model as my starting point.

Below is a WIP (Work in Progress) domain model for the skills domain. Like any good model, it is very likely to evolve over time, but at this stage it is stable enough to be valuable already. This is a key lesson to avoid analysis paralysis: Use your analysis artefacts as soon as possible. Much like software: if you use it yourself, you will notice the flaws and improve it incrementally.

So let's look at the model:

DevSkillDojo Domain Model

A good way of looking at this model would be to break it up into separate areas of concerns. The areas of concern are:

  • Skills
  • Learning Resources
  • Assessments
  • Party / Person
  • Project and Capability Requirements

In "microservice-lingo", AKA DDD (Domain Driven Design), these areas of concern could even become bounded contexts, but I think we're getting ahead of ourselves here.

For now it is more important for us to simply understand what the concepts are, and how they relate to each other.


Skills comprise the following important concepts:

  • The skills themselves.
  • The parent-child relationship that exists between skills. For example, Web Development is considered a skill, but it has many child skills, like HTML, CSS, JavaScript, etc.
  • Skills Perspective, from the skills framework, which allows us to approach different skills in different ways.
  • An enumeration of standardised proficiency levels for skills.
  • Leveled Skill, which allows us to differentiate between skills at different proficiency levels.
  • The dependency relationship that exists between skills at different levels. For example, as a Spring Cloud developer, you do require some skills in docker containers, but you certainly do not need to be an expert.

Learning Resources

Learning resources cover the vast area of learning resources that are available on the web and via other channels.

The important concepts include:

  • The learning resource itself.
  • A standardised enumeration that allows us to classify resources into types. For example: Distinguishing between a YouTube video vs. a blog article. This is important because different people learn in different ways.
  • A standardised enumeration for the size of a given resource. For example, will it take 10 minutes to complete or 10 weeks.
  • The creator of the resource, i.e. the person or team who created the content.
  • The provider through which the resource can be accessed.
  • A standardised enumeration for the different types of providers.

Additionally it is important to be aware that there are two critical association between the Learning Resources area of concern and the Skills area of concern:

  • At a general level, a skill can be developed by consuming a learning resource/
  • At a more specific level, a learning resource is associated with a skill at a specific proficiency level.

Party / Person

Skills are inherently linked to individual people, but the relationship is not a simple one.

The important concepts in this area of concern are:

  • The person.
  • A rated skill that the person possesses.

Also note that the person area of concern has three critical associations with other areas:

  • A rated skill is associated with a skill at a particular proficiency level.
  • A person may have conducted many proficiency assessments.
  • A person may be working on a particular project.


Assessments are used to determine an individual person's proficiency in one or more skills. The important concepts in this area of concern are:

  • The proficiency assessment itself.
  • A standardised enumeration of the different types of assessments (Note: This enumeration still needs some work).

As always, the assessments area of concern has a set of critical associations with other areas of concern:

  • An assessment is done by a specific person.
  • An assessment tests proficiency of one or more skills.

Projects and Capability Requirements

This area of concern is the one that recruiters are normally very interested in. You find it represented in job ads, with sentences like: "Our client is looking for a seasoned developer with experience in X, Y and Z"

It is easy to think of X, Y and Z above as just a listing of skills, but there is a subtle difference. Projects have a requirement for people with certain capabilities. And a capability is really a complex thing. As mentioned in the skills framework: A CAPABILITY is generally:

  • The application of one or more HARD SKILLS,
  • Guided by pre-existing underlying KNOWLEDGE
  • Using one or more TOOLS or TECHNOLOGIES
  • By a person with a set of SOFT SKILLS


As highlighted at the start of this post, the domain model presented here is a starting point. The model may look similar to a Class Diagram or even an ERD (if you're old-school, like me), but it's goal is very different. It allows us to talk about the concepts in this problem domain with a fair amount of intellectual rigour.

In addition to the model helping us think through the problem domain, each time we do so we may uncover additional aspects and the model may likely be adjusted. In fact, even though I prepared the diagram about 2 weeks ago, prior to the corona craziness that swept the globe recently, I made several changes while writing this article.

If you'd like to stay in touch with our progression on this journey of exploration, follow this blog ( or our twitter feed (@devskilldojo). And if you have any feedback on the framework, please drop us a note on Twitter.