When to repeat yourself

As a developer one of the first concepts you will be introduced to is DRY (Don’t Repeat Yourself) – if logic is re-used around your codebase it often makes sense to bring it into a central place to be standardised and easily maintained.  Later on in your career you might learn the hard way that there is value to be had in duplication and redundancy for the right reasons.

At Songkick we spent some time learning the hard way, so now the value of centralising common logic versus promoting weak coupling is something we actively explore and re-evaluate in our architectural decisions.

Tracking an artist versus tracking an event – be DRY on concepts, not code!

On the face of it, the concept of tracking an artist might look similar to tracking an event. For this reason we originally leveraged the same table and used a polymorphic association.

Tracking an artist vs tracking an event

Tracking an artist vs tracking an event

Looking closer and actually these two things are conceptually quite different. Tracking an event implies attendance on a specific date, and has a concept of “interested in/might go”. There is no equivalent granularity for tracking an artist (though maybe there should be a “I would consider seeing them under the right circumstances” option, look out for that in the future!).

When we split out our domain into services some years later we had to run migrations on this table to split out our attendance data from our artist tracking data, and similarly, separating logic out is much harder than combining it. Code-wise, the complexity added to handle both tracking concepts as the use cases evolved outweighed any benefit of the early abstraction.

See further reading for advice on avoiding early “optimisations” (such as abstractions).

Duplication of client models – DRY not necessarily suitable when weak coupling is required

Our front ends implement their own client models when reading data from a service, rather than making use of a client library.

Fewer dependencies gives us ease of deployment

A client library that provided standard client models may well result in less code duplication but it creates a coupling between client and service. Upgrading the client library would require a new deployment of each frontend, even if only a single frontend benefitted from the change – with our approach, we can deploy our frontends without this dependency.

If you’ve read any of our other blog posts, you’ll know we don’t like restrictions (or directives) on when we deploy!

Easier to reason about

Each frontend uses only the resources it needs and we can track our data dependencies to a service endpoint easily without the client library abstraction sitting in the middle.

Duplication of components – DRY benefits can be negligible with fast rates of change

The shared "upcoming event" component;, used on venue, metro area and user pages

The shared “upcoming event” component, used on venue, metro area and user pages

The artist "upcoming event" component

The artist “upcoming event” component

We unashamedly copy code from one front-end html component to another, making each one self-contained and with no dependency on other components. Front-end components are changed and iterated on quickly, and we usually want changes to affect a single component on a page. Any shared components are mapped out by the designer and PM so we know they will change together – if requirements differ we create a new component.

Because we make our components as dumb and atomic as possible, copying is low-cost and low-risk, and we can avoid complicated branching logic.


Optimising for code re-use might not be the right approach – consider that use cases might change, unnecessary dependencies can be created and that at the line level, code can become unreadable with an overly DRY mindset.  Be DRY, but not too DRY.

Further reading

Let’s make the Android community better

Romain Piel and I decided to submit a talk about the Android community to several conferences, on how much it has improved, the major problems it still has, and how we can all collaborate to make it better.  In one of the conferences our submission was categorised as “weird”.

Although I am passionate about fighting the lack of diversity in the tech industry, talking about it at a conference scared the bejesus out of me. How can you call out the different issues there are in the industry without pointing fingers and making people feel defensive? And besides that, I’ve never done a talk before. Is doing a non-technical talk as my first talk classifying me as a bad developer? Will it affect my career in the future? Will I forever have a stamp on my face saying I can only talk about diversity and not about other technical problems?

I had to set all my fears aside to prepare this talk. But I have the feeling the Android community is not open, yet, to this type of talks. At Android conferences, there are no talks about non-technical subjects. There are no talks about the impostor syndrome, the lack of diversity, lack of empathy, harassment, nor other problems the industry, and community currently face.

So what I am trying to do with this blog post is state why we need to start talking about the biggest problems our community has, and start addressing them.

Why I think we need to start educating each other on what causes these problems, and how can we solve them together.

Because there is not just one solution. Everyone has had different experiences, encountered different difficulties, and will have different suggestions on how to approach and solve a problem.

So here’s why I think talks on our community should be supported/promoted, and not seen as “weird”?

Because we need to acknowledge the problems

“The first step in solving any problem is recognizing there is one”. Will McAvoy, The Newsroom.

The first step to recovery is being honest, acknowledging there is a problem. That step is common for every problem we want to solve, even though it’s always related to the 12 step programs for AAs.

Acknowledging the problem is the hardest part. Many will argue that things were way worse in the past and that we should just be satisfied. I agree that we have come very far, but the problems are not completely solved and there is still a long way to go. The best example for this is diversity in the industry. Yes, we are more diverse, but women still only hold 26 percent of all tech jobs, and black and latino people only 4 and 5 percent.

Lena Reinhard – Works on my machine, or Problem exists between Keyboard and Chair

As we can see from the diagram, our community is not isolated from the rest of the world, we are not separated from society, from the tech industry, or from the companies we work for. All these different pieces have an impact on how our community behaves, how we act, how we make decisions, or what we consider wrong or normal.

So unfortunately for us, we need to understand the problems each and every one of these pieces have, and understand how they impact us.

And the piece that brings all of it together is us. And sadly we are human, which means we are not perfect, at all. So we also need to acknowledge our own flaws, biases, privileges, etc.

If we don’t start acknowledging these problems, we won’t have any incentives to start fixing them, so they will remain unfixed, and they will become the new normal. And I am sure no one wants that.

We need to start acknowledging these problems to help the people impacted by them, so we don’t leave them, or push them out of the community, to make them feel welcomed, and part of the community.

Because we need to fix these problems

“Right now, most of the people who are already working on debugging this industry are members of underrepresented groups in tech. That’s a bit like telling the QA team in your company that they have to fix the bugs they find themselves, because you have better things to do”. Lena Reinhard – Works on my machine, or Problem exists between Keyboard and Chair

It is really easy to ignore a problem, in fact it is the easiest thing to do, to turn your back to it. But that is not going to make it go away, it will probably make it worse (believe me, trying to ignore a kitchen fire doesn’t help make it go away).

K.C. Green, “On Fire”

We need to start addressing the problems and start thinking about solutions. If we are all aware of what is happening, and what the issues are, we can work together towards solutions to fix them (you know, a thousand brains work better than one).

If we ignore the problem we are limiting ourselves to a small proportion of people, we are limiting our point of view, our understanding of the world, our ideas and solutions.

If we ignore the problem we are closing the community to new people with different background and experiences, with fresh and different ideas, that probably have more to contribute than us. We would be preventing new ideas coming along and making Android better, including the community.

It is not going to be an easy process, nor fast, and it is an ongoing process. New problems will come along, and we need to be open to acknowledging them and solve them.

Because we are a community

“Sense of community is a feeling that members have of belonging, a feeling that members matter to one another and to the group, and a shared faith that members’ needs will be met through their commitment to be together” (McMillan, 1976).

If we are truly a community we should be supporting each other to be the best we can be. We need to be aware of each other’s opinions and needs, be aware of what makes people leave the community or even the industry, make new members feel welcome and meet their expectations.

We need to be supportive of each other, and empower those who don’t have the confidence to speak up.

Because other communities are doing it

The truth of the matter is that as a community, we are way behind in comparison to other tech communities when it comes to talking about social problems in the industry, or about non technical skills to become a better developer, or doing psychology talks.

Ruby conferences, Python conferences, PHP conferences, lead developer conferences, open tech conferences, JavaScript conferences, and even iOS conferences! These are just a few of them, there are a lot more communities that openly talk about these issues at their conferences. Just check the reference list to get an idea.

So, if all these communities are doing it, why are we still so far behind?

References and good videos you should watch