And what you can do to get to the next level.
Being a junior, mid-level or senior developer is not only about the years of programming experience you have. A junior developer can even be older than a senior developer. It all comes down to skill. That doesn't mean a senior developer has to be an expert in everything, but it's safe to say that senior developers are much more skilled than junior and mid-level developers.
But it's not just coding skills that differentiate a senior developer from a mid-level or junior developer. So what exactly are the differences?
Knowledge
Obviously a senior developer has much more knowledge than a junior or mid level. Knowledge of design patterns, architecture, test automation, performance, security, etc. is a good way for a junior developer to fill the knowledge gap with mid and senior developers.
It is important to know how things should be done in software development. But just knowing all these things doesn't make you a senior developer. Knowledge isn't the biggest difference between developers - it's just one factor.
Coding
Despite what most people think, coding is not about communicating with a computer. Coding is about communicating with people and instructing computers. Eventually the code is compiled and translated into zeros and ones.
The code should make sense to other developers who will work with it in the future. A new team that has never seen the code before should be able to open the code and start working on new features or bug fixes. Here is the big difference between junior and senior developers.
I'm going to omit the mid-level developer in this comparison because the mid-level developer is something of a gray area when it comes to coding skills. It's obviously somewhere between junior and senior. Probably leans more towards the senior side. It's mainly experience related since mid-level developers have probably been through the whole development cycle at least once. They have made many of the simplest mistakes and learned from them.
How to sniff out a junior developer?
Young developers are inexperienced. Most are fresh out of university and starting their first full-time job. The mindset of a junior developer is often just to make the code work. Working software and good software are considered the same.
Programming simple code is hard. And it's something young developers don't do. Young developers write sophisticated code. You can tell a junior developer by weird one-liners and overly complex abstractions. It's a junior developer's way of showing off and letting other developers know how well he can code. And it's wrong.
Young developers focus on the computational side of code at the expense of the human side.
And what about the senior developer?
When you look at the code of a senior developer, you might think: is that it? Where is the rest of the code? A senior developer writes simple, straightforward, and maybe even dumb code. This is one of the greatest qualities a developer can have when it comes to programming. A senior developer follows the KISS principle: Keep it simple, stupid. /Keep it simple, stupid.
A senior developer thinks about their code differently than a junior developer. Code written by a senior developer will be done with maintainability and scalability in mind. This is a completely different mindset from a junior developer - the senior thinks about the people who need to work with the code, while the junior just thinks about making it work for the computer.
More than just coding skills
Aside from coding skills, there are some other factors that can tell you who type of developer you are.
Junior developers, in general, perform the simplest or low-impact tasks. They do not do any architectural design. Mid-level developers don't design solutions either, they just perform tasks. The difference with a junior developer is that they perform these tasks with less supervision as long as they are assigned relatively routine tasks. Senior developers can develop an application completely on their own.
That doesn't mean the senior developer doesn't have issues along the way. Every developer has a lot of questions every day and that's not going to change. This is no different for senior developers.
The difference is that senior developers know how to ask the right questions and how to address those questions. Mid-level developers can ask the right questions when it comes to their relatively routine tasks, but need help with more complex tasks.
The senior developer is never lost and knows how to follow up the issue with the right action. This doesn't mean that a senior developer can't ask for help from other developers. Sometimes the best way is to simply ask other developers with experience in that area for help.
A mid-level developer should also be able to ask the right questions, as long as they are not assigned very complex tasks that require an in-depth level of knowledge.
You shouldn't expect a young developer to ask the right questions right away. Since junior developers are inexperienced, they need guidance from a more experienced developer. The junior developer needs to be given the necessary resources or a big push in the right direction.
Getting to the next level
We all want to improve and become better as a developer. But what are the steps you can take to get to the next level?
Junior to intermediate level
Since junior developers are inexperienced, it is important to go through the entire development cycle at least a few times. This way you will fall into many traps and learn how to avoid them next time.
When it comes to coding, you need to learn how to write simple code. Think about the next person who will be working on that code. You also need to learn how to debug, as this will give you a better understanding of what's going on in the process.
In addition, you should familiarize yourself with best practices and learn about architecture, performance, security, etc. Fill the knowledge gap that is needed to get to the intermediate level.
Middle to Senior
Getting from mid-level to senior can be quite difficult. Some developers will stay at the mid-level their entire career.
Senior developers know which corners can be cut and which corners should never be cut. These are hard-learned lessons from past mistakes.
If you want to reach the top level, you must be willing to take on the tasks that no one knows how to fix. You have to know more than how to get the job done.
As a senior developer, your job is also to help less experienced developers. You're the fallback for other developers when they don't know how to do something.
And it may not surprise you that senior developers are mastering their tech stack. There's more to it than coding skills. Familiarize yourself with all the tools and applications that are used at the company you work for.
Conclusion
The difference between a junior, mid-level and senior developer is not just years of experience. Of course, it can be said that senior developers are more skilled than junior and mid-level developers. But knowledge is not the most important factor.
Senior developers write easier code and come with a different mindset than young developers. But it's about more than coding skills. It's important to know what questions to ask and how to track those questions. And that's something that only a senior developer, with their extensive experience, knows how to do in all situations.
To develop as a junior developer, you need to focus on writing simple code and going through multiple development cycles. To get from mid-level to senior developer, you need to focus on learning more than just fixing routine tasks. You need to be willing to take on the toughest tasks and be a master of your set of technologies. Another responsibility of a senior developer is to be a backup for less experienced developers.
I'll leave you with a quote from Martin Fowler: "Any fool can write code that a computer can understand. Good programmers write code that people can understand."