Professional software developer vs a hobbyist - part 1
There are certain skills that professional software developers have that hobbyists typically lack. And no, those aren’t related to the knowledge of the syntax of a programming language or being able to solve algorithmic challenges.
While every developer needs to know the syntax of their programming language and be able to write code that solves problems, these are not enough to make one a professional developer. There are some other skills that people need to learn, too.
Surprisingly, as I have been helping both software businesses and individual developers for years, I have found that sometimes even the people who are officially employed as software developers lack some of these skills. And this is dangerous.
Firstly, lacking these skills prevents them from being as effective as they can be at their job, which puts the company that employs them at a disadvantage when it has to compete with other businesses that have more competent teams. Secondly, some of these skills are a determining factor for whether or not AI will replace your job in the near future. If you have all the skills that we will talk about shortly, then you definitely have no reason to fear AI.
There are many skills to choose from that make developers more effective at their craft. However, I chose the 10 areas that I see as the most important. I based this list on years of working as a software engineer, helping software engineering teams, and mentoring individual developers. For each skill area I’ll talk about, I will explain why it’s essential to master, even if it doesn’t seem this way for someone who’s not familiar with it.
Also, I deliberately excluded those skill areas that are too niche, such as test-driven development (TDD) and extreme programming (XP). Don’t get me wrong. I have nothing against those practices. However, I’ve seen too many successful software engineering teams that don’t follow these practices to conclude that, while these practices might be good, they are more of “nice-to-haves” rather than the essential things that every professional developer should master.
In order not to overwhelm you with information, this article will talk about the first five skill areas. We will cover the other five in the upcoming article. So, let’s begin.
1. Industry-standard best practices
Knowing how to write code to solve an immediate problem in front of you isn’t enough. As a professional developer, you need to do it in such a way that it doesn’t compromise your ability to solve problems in the future.
Moreover, professional developers don’t work as individuals. They work as a team. Therefore, the code you write must be easily readable by other team members.
Both code maintainability and readability problems are solved by the industry-standard best practices. I won’t go into details on each one because that would require a whole long-form article on its own. However, here’s a brief overview of some of the practices that every professional developer must be familiar with:
DRY (don’t repeat yourself) principle: dictates that you should not be duplicating the same piece of logic in several different places. If you need to reuse a piece of logic, turn it into a shared method or a function.
KISS (keep it simple, stupid) principle: don’t over-complicate things. Don’t add more functionality than strictly necessary. Try to express the functionality in simple terms that are easy to understand.
SOLID principles: a collection of guiding principles on the structure of the elements in your code, so your code base becomes easily readable and maintainable.
Clean architecture: principles of structuring your application at a high level, such as separating it into different layers of clear responsibilities (e.g., presentation layer vs business logic layer).
This list is non-exhaustive, and there are many more. I will cover some of these principles in more detail in my future articles.
2. Naming convention of your programming language
When you just learn to code, your first priority is to figure out how to get your code to run. However, when you start writing code professionally, this is no longer enough. You also need to adhere to the standard styling practices and naming conventions.
From the compiler’s perspective, it doesn’t matter whether your function starts with a lowercase or an uppercase character. Likewise, if your programming language uses curly braces, it doesn’t matter whether the opening brace starts on the same line as the function name or the next line.
It’s very common to see people arguing online about these “personal preferences”. However, when they do, they immediately reveal themselves to be either amateurs or novices.
True professionals don’t argue about these things. And it’s not because they are “above it all”. It’s because these things aren’t personal preferences at all. Each programming language has its own set of accepted stylistic standards, and if you want to be perceived as an experienced professional, you will need to learn the ones your language uses.
As an example, here’s a list of C# conventions that I wrote about some time ago.
3. Source control
Source control (also called version control), of which the most popular is git, is the bedrock of modern-day software engineering. It treats code as a living, collaborative artifact rather than a static deliverable. Source control will be useful to you even if you are merely an amateur. However, for a professional developer, it is absolutely essential.
One of the biggest reasons to use source control is risk management. Bugs, failed experiments, or accidental deletions can happen at any stage. A source-control system keeps a complete, timestamped history of every change, letting developers roll back to a known-good version.
But risk management is not the only benefit of using it. Whether you’re two or more engineers sharing a side project or thousands contributing to a global codebase, source control provides the canonical “single source of truth.” Branches and pull/merge requests let people work in parallel without trampling on each other’s work.
Finally, there’s traceability and accountability. Every commit records who changed what and why (via commit messages and issue links). This audit trail is invaluable for regulatory compliance, post-incident forensics, onboarding new teammates, and demonstrating progress to stakeholders.
4. Systems thinking
When you develop software, you don’t just write code for the sake of writing code. In fact, people who hired you don’t care about the code at all. You’ll need to look at the bigger picture.
Systems thinking is the habit of looking past an individual class, function, or service and instead reasoning about the whole socio-technical system: the code, the runtime environment, the data flows, the people who build and operate it, and the business context it serves.
Rather than reducing problems to isolated parts and only focusing on a narrow technical implementation, you model how those parts interact, spotting feedback loops, bottlenecks, emergent behaviors, and unintended side effects. In practice, this can involve drawing causal-loop diagrams, mapping the “value stream” from commit to customer, or simply asking “what else does this touch?” every time you add or change a feature.
Why is systems thinking important? The same reason the programming best practices are important. When you look at the bigger picture, you don’t just solve the immediate problem in front of you. When you consider how the component that you are modifying interacts with other parts, your solution to the current problem won’t compromise your ability to solve similar problems in the future.
But there’s more to it than this. Systems thinking allows you to question whether or not you are even solving the right problem. This is true engineering at its finest. If you master this, you will be irreplaceable.
5. Writing tests
Once you've written your code, you need to make sure that it works. One of the ways of doing it is to launch your application and test it manually. However, as your application grows, this becomes harder and harder. If we are talking bout full-scale enterprise applications, this may take hours.
Of course, you can reduce the scope of testing to only do those parts of the app that you modified. However, this isn’t a good strategy. There’s a type of software defect known as a “regression”. This is where a part of the system that was working absolutely fine previously was accidentally broken by something else. And there is always such a risk present!
However, there is a solution to both testing your software and preventing regressions from happening. Both can be solved by adding automated tests.
When tests run on every commit, they instantly tell you whether a change preserves the intended behavior, letting you move fast without the fear of silent breakage. This continual feedback loop not only catches defects early, when they’re cheapest to fix, but also encourages bolder refactoring and experimentation, since you can always prove you didn’t break anything important.
Automated tests also serve as executable documentation. Clear, well-named test cases illustrate how the system is expected to behave in edge conditions that prose alone rarely captures. New team members can read and run the suite to understand key workflows much faster than combing through code or wiki pages, accelerating onboarding and reducing reliance on tribal knowledge.
Wrapping up
These are the skill areas that differentiate a professional software developer from an amateur. But we have only started. In the next article, we will talk about the other five skill areas that are just as essential. If you haven’t subscribed already and want to find out what they are, feel free to subscribe to make sure you don’t miss the upcoming article.
Also, I wanted to let you know that I routinely help both individual developers and software engineering teams to upskill. If you are interested in learning more, you can book me via the following website:
https://scientificprogrammer.net/
I hope you have a great day, and I’ll speak to you next time!