What’s most interesting about reading lots of code is that you get a fairly deep insight into how people think. Building software solutions involves decomposing a bunch of related problems into discrete pieces and then recomposing them back into a solution that allows users to get their work completed. Examining these pieces shows both how the individuals involved break apart the world, and how much they understand of the it to be able to put it all back together again.
Supplemented with an understanding of the history of the development and enough experience to be able to correctly visualize a better solution, this can allow us to analyse various types of common thinking problems.
The first, and most obvious observation is whether or not the programmers are organized. That just flows right from how much structure and consistency is visible. Since most large bodies of code are written over years, there can sometimes be local organization, but that might change radically in different parts.
Organization is both external and internal. It applies both to the overall process of development and to how the analysts, designers and programmers arrived at the code.
Internal organization, as it applies to thinking, is in a sense how fast one can head in the right direction, rather than just wander aimlessly in circles. Often times checking the repo sheds light, in that disorganization usually generates a large number of small fixes that come in sporadically. A good testing stage should hide this from the users, but in broken environments that doesn’t happen. So really messy code, and a boatload of little fixes, generally sets the base thinking quality. If the fixes are spread across fairly large time spans -- implying that they are driven by users, not testers -- then a significant amount of the thinking was rather disorganized.
Disorganized thinking is generally fairly shallow, mostly driven by the constant lack of progress. That is, people who make little progress in their thinking tend to want to avoid thinking about things because it doesn’t ultimately help them. That pushes them to the tendency to react to the world in the short-term. But long-term planning and goal achievement, almost by definition, require deep thinking about both the future and the means to get there. Thus disorganized thinkers are more often a-types that prefer the bull-in-the-china-shop approach to handling problems. For the most part there seems to be a real correlation between the brute force approach to coding and disorganized thinking. It’s the “work harder, not smarter” approach to getting things done.
Another really common thinking problem that is visible is with local simplification. It’s not uncommon to see programmers go from A to B via all sorts of other crazy paths. So instead of going straight there they go A -> M -> Q -> B, or something equally convoluted. Generally if you get a chance to inquire, many of them will rather confidently state that since A -> M is shorter than A -> B, that they have actually simplified the work and that they are correctly following an approach like KISS. What they seem to have difficulty understanding is that A -> M -> Q -> B is inordinately more complex. That the comparison between the two approaches is flawed because they aren’t comparing two equal things, rather just a part of the solution vs. the whole solution. You see this quite frequently in discussions about architecture, tools, design, etc. and of course these types of complexity choices get burned directly into the code and are quite visible.
In a programmatic sense, any code that isn’t directly helping to get to the destination is a possible suspect for being an M. More specifically, if you ignore the code, but follow the data instead, you can see its path through the runtime as being a long series of data copies and translations. If the requirement of the system is to get from the persistence storage to a bunch of widgets and then back again, then unless intermediate destinations are helping to increase performance, they are really just unnecessary waypoints. Quite often they come from programmers not understanding how to exploit the underlying primitive mechanics effectively, or from them blindly following poor conventions. Either way, the code and the practices combine to consume excess work that would have been better spent elsewhere. In that way, local simplifications are often related to shallow thinking. Either the programmer came to the wrong conclusion about what really is the simpler approach, or they just choose not to think about it at all and decided to blindly follow something they read on the web. Either way, the code points back to a thinking problem.
The third, and most complex problem, is with the decomposition of things into primitive parts. It’s easy enough to break a large problem down into its parts, but what isn’t often understood well is that the size and relative positioning of the parts actually matters. There are nearly an infinite number of ways to decompose a problem, but only a select few really make it easy to solve it for a given context. Ideally, the primitives fit together nicely; that is there are no gaps in between them. Also, they do not overlap each other, so that there is a real canonical decomposition. They need to be balanced as well, so that if the decomposition is multi-level, each level only contains the appropriate primitives. This whole approach is mathematical in nature, since it adheres to a rigid set of relative rules, created specifically for the problem at hand.
A problem broken up in this manner is easily reassembled for a solution, but that’s generally not what we see in practice. Instead, people tear off little bits at a time, rather randomly, then they belt them out as special cases. The erraticness of the decomposition provides great obstacles towards cleanly building a solution and as it progresses over time, it introduces significant spaghetti back into the design. It’s the nature of decomposition that we have to start from the top, but to get it reasonable we also have to keep iterating up and down until the pieces fit properly; it's that second half that people have trouble with because that type of refinement process is often mistaken as not providing enough value. However, it really is one of those a-stitch-in-time-saves-nine problems, where initial sloppiness generates significantly more downstream work.
A more formal background makes it easier to decompose into solid primitives, but given the size and complexity of most problems we are tackling, knowledge or even intrinsic abilities does not alleviate the grunt work of iterating through and refactoring them to fit appropriately. This then shows up as two different thinking problems, the first being able to notice that the pieces don’t fit properly, while the second is being able to fix that specific mismatch. Both problems come from the way people think about the underlying system, and how they visualize what it should ultimately look like.
Now so far, I have been using the term ‘thinking’ rather loosely, to really refer to what is in between observations and conclusions. That is, people see enough of the problem, and after some thinking, they produce a solution. That skips over issues like cognitive bias, where they deliberately ignore what they see that does not already support their conclusions. Given that it is internal, I do consider that part of the thinking process; the necessity to filter out some observations that don’t fit the current context and focus. Rose-colored glasses however are very common problem with software development. Sometimes it related to the time pressures, sometimes it's just unreasonable optimism, but sometimes it is an inability to process the relevant aspects of the world around us. It is a thinking failure that prevents us from being able to build up internal models that are sophisticated enough to match observed evidence. To some degree everyone is guilty of wearing blinders, of filtering out things that we should not have, but in some cases it is considerable more extreme than that. It’s really a deep seated need to live within an overly simplified delusion, rather than reality. Strangely that can be as much of a plus as a minus in many cases, particularly if success is initially difficult. Ignoring the obvious roadblocks allows people to make a full hearted attempt. But as much as it can launch unexpected successes (occasionally), it becomes increasingly negative as time progresses and the need for more refined thinking grows more significant.
Analysis, design and programming are all heavily dependent on observation and thought. In the end, a software system is just an instantiation of various people’s understanding of a solution to a problem. In that, it is really only as strong as the sum of its commonly used weakest links (some parts of the system are just irrelevant). So, if the quantity of the observations are compromised by time, and this is combined with poor thinking, the resulting system most often falls far short of actually solving the problem. It is not uncommon to see systems that were meant to cut down on resources, need significantly more resources than they save. That is, a grunt job for 4 people is so badly automated that 6 people have to be involved to keep it running. In that sense, the system is an outright failure and underlying that is not a technical problem, but rather one about how various people came to think about the world, and how they combined their efforts to solve things relative to their conclusions.
Thinking well is a prerequisite for handling complex problems, with or without technology. If people can’t clearly understand the issues, then any attempt to solve them is as equally likely to just make them worse. If they break down the problem into a convoluted mess of ill fitting parts, then any solutions comprised of these is unlikely to work effectively, and is more likely to make things worse. Software, as it is applied to sophisticated problems, is inordinately complex and as such can not be constructed without first arriving at a strong understanding of the underlying context. This comes from observations, but it doesn’t come together until enough thinking has been applied to it to get it into a usable state. Software in this sense is just well-organized intelligence that gets processed by a computer. There is no easy way around this problem.