[Engineer Mindset] Why do engineers care about code quality? [2026/04/09]

Why do engineers care about code quality?

[Problem Statement]

"Isn't it fine as long as it works for now?"
Just before the deadline,the features are all complete.
However,in the review,"This code will definitely cause problems later"it gets sent back.
In an atmosphere where release is the priority, why do engineers insist on code quality?.
To put it more simply,
"If it's working, why fix it?"
have you ever wondered that?

[Common Phenomena]

The following situations are often seen in the field.
・It works, but the variable names and structure are hard to understand and are pointed out in reviews
・Refactoring is proposed even though the deadline is approaching
・Implementations that are fine in the short term are rejected as "becoming technical debt"
・Looking back at code you wrote in the past and feeling "why did I write it this way?"
I'm sureyou have experienced each of these at least once.
"It's not a problem now, so why care so much?"is a point where a sense of discomfort easily arises.

[Why does this happen (structure)]

There are several structural factors behind this.

First is thetechnical reason.
Softwareis not something that is "made once and finished"but rathersomething that is "continuously changed"by premise.
As specification changes, bug fixes, and feature additions are repeated, the readability and structural quality of the codedirectly affectsubsequent development costs.
In other words,low-quality code exponentially increases the cost of future changes.

Next is the perspective of project management.
In the short term, ignoring quality can sometimes make things look faster.
However, in the long term, risks such as an increase in bugs, longer correction times, and dependency on specific individuals accumulate.
As a result, the overall progress speed of the project slows down.

Organizational structure also has an impact.
Development teams share code among multiple people.
Low-quality code increases the understanding cost for other members, creating friction in communication.
Because the burden of reviews and handovers increases, it affects the productivity of the entire team.

And then there is human psychology.
Once written, code easily becomes something people do not want to touch.
The more complex and difficult to understand the code is, the more it is avoided, and as a result, it is left alone.
This untouched code accumulates as technical debt over time.

[Engineer Psychology]

Engineers caring about code quality is not just about aesthetics.

Many engineers are conscious of code that will be read by themselves or others in the future when they write it.
The code written by oneself today can feel like someone else's code after a few months.
Whether it is easy to understand at that time is quite important in practice.

Also, code is an output of thought as well.
Code with unorganized structure suggests the possibility that it was implemented while understanding of the problem or design remained ambiguous. In other words,
a commitment to quality is also a desire to think correctly. a desire as well.

Furthermore, past painful experiences are likely a major factor.
The experience of having struggled later because I cut corners at that time experience leads to a strong awareness of quality. Isn't this something that
engineers who have experienced the field feel more strongly?

[Structure of the IT Industry]

This issue is not about individual personality, but is also closely related to industry structure.

IT development is required to have short delivery times and high-frequency releases while also assuming long-term operation. The fact that this
balance between short-term and long-term is constantly required is a characteristic.

Also, there is the issue of evaluation systems. While
short-term results (meeting deadlines, number of features) are easily evaluated, the long-term value of things like code quality is hard to see. Therefore,
quality improvement activities tend to be neglected.

Furthermore, personnel rotation between projects also has an impact.
The person who wrote the code leaves, and someone else maintains it. Because of this premise,
code that anyone can understand is required.

[How can it be improved?]

As a realistic approach, the following methods are effective.

First, create a culture of small improvements. Even if
large-scale refactoring is difficult, making small improvements during daily fixes is possible. The mindset of
improving the parts you touch just a little bit is realistic.

Next, improve the quality of reviews. By sharing
why something is a problem rather than just pointing it out, the team's overall understanding deepens. As a result,
quality standards become aligned.

Also, explicitly stating the trade-off between quality and speed is important.
How much quality to guarantee varies depending on the project situation. Instead of
proceeding while things are ambiguous, making intentional decisions is necessary.

Finally, utilizing automation. By
introducing format checks and static analysis, you can lower the cost of ensuring quality.
Building a system that does not rely too much on human effort is the key.

[Summary]

Engineers care about code quality because of factors such as:
・The fact that software is structured to be continuously modified
・The fact that quality is directly linked to future costs and risks
・The fact that readability is crucial in team development
.

Actions that might seem like obsessing over details at first glance are actually based on long-term rationality.

That said, it is not realistic to always aim for perfection.

What is important is understanding why quality is necessary and then, striking a balance based on the situation, wouldn't you agree?

Thinking about it that way, a commitment to code quality is not just an aesthetic, but perhaps it could be called a survival strategy as an engineer.