Target audience : People with intent to be a software developer
Let’s skip the part of reasons and motivations that make you decide to be a developer, it’s maybe your interesting, or it’s just about money, or the life just pushes you to, etc , this post is to give you some guideline to go on this road.
Developers is likely heroes in games you play. What skill that hero should have, how to level up, which criteria to put points to after level up, which bosses to defeat and the most important thing is whether you understand the story behind the game you are playing, to enjoy it !
Let’s start with the story of developer
Software Developer world map
Developers, software developers is to create applications to solve real life problems to serve human need. Finding the need is a difficult task too and it deserves to discuss in another post.
There are many kind of applications. Names of application kinds depends on where it run and how it run. It is up to you to choose to follow one or many.
- Desktop application : Applications that run on computer / laptop with UI for user to interact with
- Web application : Applications that put in a server and you access by using web browsers. There is 2 parts of a Web application called Client side & Server side. Technology used in each side is different too.
- Mobile application : Applications that run on mobile phones, now include Android & iOS
- iOT application : Applications that run on multiple devices connected to each others in some network model
Imagine this is hero class selecting phase of the game you gonna play. Let thanks god because you don’t have to name your character :)). But each kind of application requires you to use appropriate tool sets.
There is another kind of define developer class when model client-server application model is dominant nowaday, it is :
- Front-end developer : Is ones who take care of Graphical User Interface (GUI) for user to interact with. It includes Desktop Application, Mobile Application and the client side of Web Application
- Back-end developer : Is ones who take care of something like system architecture, database, etc, things that are not visible to normal users.
To create any application, you are required to know
- A programing language for your kind of application
- A Integration Development Environment (IDE)
- A framework or libraries for your kind of application
- A database for your kind of application
- A package management tool for your kind of application
- Know how to deploy/release your kind of application
- Know how to test your applications
Programing language is your weapon. It will determine which kind of application you can make. Below is the most popular languages at the moment of this post
- Java : well-known as a cross platform language, Java can be used to create desktop application, server-side of web applications, Android applications
- C# : for Desktop applications on Window
- Python : good for build tools but also good to build Web application
- Kotlin : well-known for Android development and as a replacement for Java in mobile world
- Object-C, Swift : well-known for iOS development
- PHP : well-known for decades in web application development
A lot of languages right ! Everyone wonders which is better than others. The answer is none. Each language has its own benefits and use cases that we will discuss later. And nowaday, it is very normal that a developer can use more than 1 language.
IDE is the software built for developers, to make their life easier when dealing with common problems while writing code:
- Remember syntaxes
- Remember boilerplate codes
- Command lines
- Compile code, debug & run
- Setup environment
- Search usages of a function or varible
- Search a piece of code / text among a bunch of files in a project
- Organize project
- Format your code for readability
The most of IDE provide features like code suggestion or auto complete to that help you type faster and more correct and more readable, to avoid most of typo mistakes. They also have excellent text searching feature that really helpful for troubleshooting problems with your code. Some advance IDEs even can suggest you what need to do and what to do next in what you are doing. And debugging support, this one will save you a lot of time – sometime you have no idea what you are writing, trust me :)), debugging is the only way to figure out. Below is the most advances IDEs currently :
- IntelliJ : the best at my point of view, but it is not free. But you may find some crack somewhere :))
- NetBean : Free, very equal to IntelliJ
- Visual Studio : Free, most popular IDE, usually used in academic courses
- Android Studio : Dedicated for Android developing
- XCode : Dedicated for iOS developing
Learning to use a IDE may take time too but it is worthy. It helps you more efficient and look professional too.
Framework / Libraries
Language is weapon but know how to use weapon deadly is matter too. Imagine it is likely that why you need to learn kung-fu while you have arms & legs already. Framework is built by top level developers and it is embedded with programing experience in decades. It provides ready to use structural solutions in for very common programing problems , kinda of best practices. A little different from framework, Library is a set of tools that help you solve programing problems but not strict in a predefine structure like a framework, you are the one who are responsible for that structure. Below is some most popular nowaday framework/ libraries. The popularity here depends on the demand on job market : (the order is no meaning)
- JavaFX : built from Java, for Desktop application
- .NET : built from C# ,well-known good to build Desktop application, but it also can build Mobile Application, Web Application and iOT application too.
- Spring : built from Java, for server-side of Web application
- ExpressJS : built from NodeJS, for server-side of Web application
- Android Studio itself contains a framework to develop Android application
- XCode itself contains a framework to develop iOS application
- Laravel : built from PHP, for Web application
- Django : built from Python, for Web application
Database to store data. Depend on your purpose , it can be the most advanced storing technology or just simple files.
Below is some popular database technologies to learn about database for Web application:
- SQL : Typical relational database.
– Relational database means it requires data to be stored in a structural way, with clear relationships between them. SQL offers a strong transactional query (that we will learn later) that ensure consistency of data.
– SQL is a good candidate for applications that dignify the data consistency over other features ( like banking system, accounting system for example ).
- MongoDB : Typical Non-relational database (NoSQL), easy to scale but requires extra setup effort.
– MongoDB can be a great choice if you need scalability and caching for real-time analytics; however, it is not built for transactional data.
– MongoDB is frequently used for mobile apps, content management, real-time analytics, and applications involving the Internet of Things. If you have a situation where you have no clear schema definition, MongoDB can be a good choice.
- PostgreSQL : like SQL but more advanced with additional features.
- Couchbase : NoSQL type, with Sync Gateway allowing to synchronize data between server and client side seamlessly. If you need an application with realtime data update, Couchbase can be a good choice
- Cassandra : NoSQL type, support scaling out-of-the-box. If you need a database that is easy to setup and maintain regardless of how much your database grows, Cassandra can be a good option. If you work in an industry where you need rapid growth of your database, Cassandra offers easier rapid growth than MongoDB.
Databases for Web application are usually hosted in dedicated server for best performance to serve from hundreds to millions requests per minute
Different from Web application databases, Client side applications like Desktop application or Mobile application require more lightweight solutions to store data locally. Data that client side applications store usually are application settings, user preferences, static data, cache data from remote database (if it has a server side), etc
- SQLite : SQL type
- Realm : NoSQL type and faster than SQLite in common operations
- Couchbase Lite : a counter part with Couchbase database in server side, with builtin sync features
Thanks to community , each language today has it own libraries to interact with databases. Unlike language, you should know more than 1 type of databases, at least 1 in SQL type and 1 in NoSQL type to feel different ways to solve a problem.
Package management tool
Building an application means solving a lot of problems. Thanks to community, the world of open source, most of problems are solved and packaged out there. When you build an application, you always need a few or a lot of them.
To manage the structure of the project and to bring more autonomous to application building process, each language usually has its own package manager tool(s) to :
- Install/Update/Uninstall packages
- Create a building cycle of the application for continuous development and integration
- Manage project structure in consistent way but easy to expand too
Below is some Package management tools for each language :
- For Java application : Maven
- For Android application : Gradle
- For HTML & CSS : Bower
- For PHP application : Composer
- For Python application : pip
- For C# : NuGet
This is the critical phase of building an application. It is bring what you build to the real world, where people can access it, and use it. It depends on kind of application that we use term deploy or release. If you are building the server-side application, we use term deploy, because you are going to send your application to a server, to execute. And if you are building the client-side application , like Desktop app or Mobile app, we use term release.
- Android & iOS applications have its own release processes that you can find in official documents of them. IDEs usually support application release process . Then you have to learn the process to uploading your applications to Play Store (for Android) and Apple store (for iOS)
- Desktop application is easiest, the version you build while developing can be used as release version already. Your next work is to introduce it to your customer
- Deployment process is more complicated. Because the server is mostly run on Linux OS nowaday, it is very recommended to learn how to operate a Linux OS, at least know how to connect to a remote Linux server via SSH & execute command lines when a tutorial asks you to do. More detail about Linux will be in another dedicated post. It depends on the language or the technology you choose that has a different deploy process. We will mention in another posts case by case.
Test your application
Last but not least, testing your application before delivering to the real world is an important phase that make sure you don’t disappointed people or lost customers.
The most basic technique of testing is manual test. Yes, you try your application in every cases and every ways can have to make sure it does not crash.
The more advanced technique is automation test, where you write code to simulate every use cases with your applications. This way is more professional, and more efficient, but also more skill to be required.
In automation test, there is a few sub kinds too. I name here only kinds I mostly use :
- Unit test : is to test the correctness of functions or a set of functions.
- Integration test : is to test the correctness in functioning of a group of components of your applications. In integration test, you have to simulate every actions in UI to interact with the application
To learn about automation test, below is some libraries for doing test in languages :
- JUnit : Unit test library to test Java program
- PHPUnit : Unit test to test PHP program
- unittest : Unit test library to test Python program
- Selenium : great tool to do integration test for Web application. It is a browser basically but controlled by developers
- AutoIt, Appnium : great too to do integration test for Desktop application
- Espresso : included in Android Studio, to do integration test for Android application
- XCUITests : included in XCode, to fo integration test for iOS application
Wrap it up
You may concern that why iOT application is rarely mentioned in above lists. It is because iOT application includes many applications in many devices. Depends on what kind of device, you may choose yourself any tool above to develop. For example, You may have a phone to control electric circuit in your house, so you have to develop an Android application and a Java application on the device controlling the circuit, a Rasperri Pi for example.
To wrap it up, I note down below some popular skill sets currently for you upcoming hero to choose:
- Web application in Java : Linux, Java, Servlet, Maven, JUnit, Selenium, ReactJS, HTML, CSS, PostgreSQL
- Android application : Kotlin, Gradle, Expresso, Realm / Couchbase Lite
- iOS application : Swift, XCUITest, Realm / Couchbase Lite
To proficient in any skillset is time consuming, it can take you years but don’t worry, most of companies don’t require you to master all of this before applying for a job unless you are applying for Senior position. Most of times, people master their skill via their job. So keep learning and learn in the right track