It is a popular perception in software engineering that there exists a trade-off between code health and delivering software fast. This is a huge misconception fueled by the fact that we very often maneuver ourselves into such a situation, where we suddenly have to decide between improving the quality of our codebase and delivering new features.
Yes, this trade-off is real and I have experienced it myself more often than I would have liked to, but the underlying problem is that we allow this trade-off to materialize in the first place without actually getting anything in return.
In the remainder of this post I will look into some of the reasons that create such trade-off situations, how we could avoid them and what we could do to get out of them.
Before going more into detail, a short disclaimer: Everything I present in this post (and in this blog in general) is my personal view and does not represent the view of my current employer, my former employers or any future employers.
Accumulating Technical Debt
Having a large amount of technical debt is the reason why we experience this trade-off between code health and delivering features fast. So why are we getting into this vortex of technical debt? There are three reasons for that.
First, we very often incorrectly perceive that by going into technical debt we are able to gain short-term advantages which potentially outweigh all the long-term downsides. But in software development this is just not possible. Alright, there are a few notable exceptions here, like the one-off script, the small prototype or the feasibility study. But even in those cases, how often did we need our one-off script more than once? How often did our small prototype grew over time until it made it into production? How often did our feasibility study require time-consuming debugging until it gave correct results? I do not want to claim that those exceptions do not exist, but they are extremely rare. In all other cases, there are no significant short-term benefits from going into technical debt. Technical debt hits us much faster than we expect, even for single-person short-term projects, but more so for multi-developer projects with a long lifetime.
Second, we sometimes just do not know how to do it better. Each developer has a specific set of skills and experiences. Even by doing our best, we might immediately introduce additional technical debt. And this is one of the reasons why I personally do not like the term technical debt. While we go into technical debt consciously, but based on false premises, in some cases (first point), we mostly go into technical debt accidentally (this point and the next one). And this is not how you typically get into other forms of debt.
And third, even in cases where we do know how to implement things perfectly, we get it wrong. Actually, we get it wrong all the time. And not because we are missing skills or experiences, but because we are not able to predict the future. We are implementing something in software (and not hardware), because we expect the implementation to change over time. Even in cases where our current implementation is perfect (whatever that means, but this is a different story), it might be far from ideal in one month from now or in half a year. And that means that we get additional technical debt just because the context (e.g. constraints, requirements, scale, etc.) changes over time. Again, the term debt does not seem appropriate here.
How to avoid Technical Debt?
Looking at the three different ways in which we are adding technical debt, how can we best avoid it? First of all, lets not get lured into consciously adding technical debt by the false premises of short-term gains. In most cases, this is not what we get back in return. So what about the other two cases in which we accidentally add technical debt?
We can reduce the amount of technical debt that is added because we were not able to find better ways of implementing or designing a feature by getting better ourselves. Continuous learning and improvement is something I am very passionate about. It takes time, but there are plenty of resources (books, videos, courses, etc.) available that could help us to avoid repeating the same mistakes we (or other developers) did in the past. Those are techniques like test-driven development, pair programming, code reviews, refactoring, patterns and many more. I always wanted to compile a list of useful resources and might be able to add it in the next days, so you have some starting points.
What about the technical debt that is added because the context of our project has changed? Well, we can easily avoid this by getting better at predicting the future. Just kidding. While we might get better over time about making reasonable predictions of the future, this will never be sufficient to avoid this issue altogether. What we can do is to accept that we will get things wrong and to design the system with that in mind. This is not easy at all and in my opinion one of the most difficult things in software development. But by designing the system for change, by deferring decisions and by keeping the codebase simple and modular, we can mitigate a lot of technical debt as soon as it occurs.
Whatever we do, we will sooner or later accumulate technical debt. Even a team with the most experienced and skilled engineers will have to deal with technical debt. The important thing here is to continuously deal with it and to reduce it as soon as it occurs. As long as we are able to keep technical debt below a critical threshold (and this threshold is not very large), we are not getting into the situation where we have a trade-off between code health and feature development. This is what we should aim for. But what if we are above that threshold?
How to reduce Technical Debt?
Working in a project with a large amount of technical debt is not a pleasant situation to be in. As I said before, this is something we should try to avoid from the very beginning. Don’t get into such a situation.
But what if it is too late or if you just joined a new project which is in an unhealthy state? It can be extremely stressful to work in such an environment. If that is the case for you and if the situation is not improving, I would recommend to look for other opportunities and to not remain in that situation for too long.
In any case, if we are in such a situation, we basically have to deal with the uncomfortable trade-off between code health and feature development. That means there has to be someone in the decision chain which supports reducing technical debt. If that is not the case, I doubt that such an endeavour could be successful and would like to refer to what I said in the previous paragraph. If, on the other hand, reducing technical debt is a priority, it will still be a very difficult task, but there are a few things we can (at least try to) do.
Replacing the whole system is most of the times very risky and something I would generally advice against. Instead, I would try to reduce technical debt more locally. I would start by improving testability and test coverage in order to increase the confidence in the codebase and to make further changes easier. Being able to change code with confidence might allow us to modularize some components and decouple them from the rest of the system. Replacing such components with better implementations does not come with the same risks as doing it for the whole system and is something that worked very well for me in the past. Apart from that, as a general rule we could try to simplify any code we touch for maintenance or for feature development. This allows reducing technical debt while developing new features and might slowly move the whole project into a more healthy state (where other changes might become feasible).
All in all, this is not easy. I am not sure if I mentioned that before, but the whole point of my post is to avoid getting here in the first place. And if you end up here, then good luck.
There is no fundamental trade-off between code health and delivering features fast. We experience this trade-off because of a large amount of technical debt. Being in such a situation is very unpleasant and significantly slows down the progress of projects. In the extreme, it makes projects fail.
And this is why we should be mindful about technical debt, the reasons why we accumulate technical debt, how to reduce technical debt and most importantly, how to avoid adding technical debt in the first place.
This is easier said than done and I hope I will find the time to get into more concrete examples here in this blog. Please let me know if there are any specific topics you would be interested in.