To begin with, I created a microservice on my hosting, which contains a database of phrases in mysql and provides phrases through the REST API. I implemented this through a small service I wrote in golang. To simplify filling in the database, I also created a small utility (also on golang) that loads phrases from a text file into the database. Thus, i can supplement the database, change categories, or the likelihood of issuing a phrase without having to update the application on Google Play.

The application is entirely written in Kotlin. To work with the microservice, I used Retrofit. Also, using Retrofit, the application uses the Google Translation API to get the translation of phrases into any language. I used Dagger2 to manage dependencies. For my project, it is certainly redundant, but the purpose of creating the application was to gain experience.
The result is an interesting application with a clean architecture that any developer can easily figure out.

You can view the app here

I made this site to tell a potential employer about myself, as well as to save some of my projects here.

I didn’t want to make the site completely from scratch, but at the same time it would be ugly to use other people’s developments for my purposes. Plus, I didn’t find the portfolio template in the form I needed. I had to take as a basis pure WordPress and a template based on bootstrap.

I estimate my PHP knowledge as basic, but I quickly figured out the structure of the template, added the pages I needed. I had to tinker with the portfolio. I studied the structure of wordpress templates in depth for several days and finally got the job done. Portfolio items are now easily added in the WordPress console and are displayed correctly on the site in the form of cards that can be turned over or additional information can be obtained by clicking on the appropriate button. Everything turned out exactly as I planned

So, after spending part of my vacation, I created a website and gained valuable experience.

You can view the site here

A small landing page that I made using Bootstrap 4. There is nothing to describe here, everything was very simple – I read the Bootstrap documentation and did it. I used free libraries for animations.

You can view the site here

After studying the reviews on Mini locator, I decided to create a separate application with a friendlier interface and with improved features, because opinions were divided – someone wanted more features in Mini locator, while others, on the contrary, thought that new features would ruin the application.

While developing this application, I decided to learn Kotlin. For about a week I got used to the syntax of the new language and found it very comfortable! Also during development, I actively used Room, LiveData. I made animations myself, including SVG animations. For the drop-down float action button, at first I was going to use a third-party library, but I realized that I can easily implement it myself, which I did. Among the important stages of development, I would mention the following:

• I implemented the arrow and camera activities in such a way that they are controlled by the same manager, which greatly reduced the development time.
• I also gained experience in implementing messaging between service and activity.
• I used git extensively when developing the application. To do this, I installed gitea on my VPS.

The description of the application can be viewed here
or google play

Retro Labyrinth is an attempt to make a copy of a real-life puzzle, as well as gain experience in game development in Unity.

During the development, I met some difficulties – initially I planned to make the game fully 3D, but the performance of my smartphone was not enough for a good physics simulation, so I went for a trick. I rendered the previously created 3D model of the labyrinth in a top view, I also converted the balls into a 2d sprite, made a physical model of the labyrinth so that the balls correctly bounce off its walls and in the end I achieved what I wanted – the balls bounce off the walls of the labyrinth and from each other just like that, as I needed!

The game can be found on google play

The first version of the application was created in 2014, but I deleted it from the market because I found this application not convenient enough (this was my first experience in developing for Android).

However, in 2018, many users of the application contacted me with a request to return it to the market and adapt it for newer versions of Android. I was very surprised to have fans of this application and decided to re-publish it, adding some new features.

While creating this application I got a good experience with GPS coordinates, custom View.

When designing an application on google play, I decided to make a short video clip. As a result, I got a good experience in working with 3D graphics and animation in Blender

The application can be viewed here

Checkers game was made in Visual Studio 2017 in C ++, Win32 API.

I used GDI for drawing checkers. The task here was not to create an invincible AI, so there is no analysis of future moves. AI moves are only based on the current situation on the board. This is enough to defeat a beginner or an inattentive player. Thanks to this project, I remembered what pointers and references are in C++ and how to work with the Win32 API.

More information can be seen in my Russian blog

This project was created to keep records of applications and additional services in the field of housing and communal services. The most difficult thing was not programming, but a clear understanding of the technical task. I had to understand the tariffs and methods of accounting for the organization’s services .

I built my work with the SQL Server database on a single singleton, whose methods allow to work with tables and database views using SQL queries, and encrypt data if necessary. In the database, I actively used views and triggers to simplify the implementation of some algorithms.

I have implemented the generation of reports using the RDLC files. I combined several similar reports into one universal rdlc file, which was modified after loading. It significantly accelerated the development of these reports.

More information can be seen in my Russian blog

I don’t like programming in Delphi, because I think this language is quite outdated, but in this case it was one of the customer’s requirements – the application must be written in Delphi XE5, and also use a MySQL database. I used FastReport to generate reports.

The biggest difficulty was the lack of technical requirements from the customer. I had to spend a whole week studying various materials, principles of psychological testing, and coordinating with the customer the tasks that the app will perform.

The app is installed at the teacher’s workplace and at the student training places. The teacher can start a new test, edit existing tests, or create new tests and analyze test results. Students register in their groups and complete answer questions in tests.

Other screenshots and some details can be found in my blog (in Russian)

This game is very simple – you press the button and the dice roll.

All throws are recorded in the text log. After the game ends, the best result is saved in the SQLite table.

I didn’t usually use 3D models in .NET, this was new to me. I had to read Microsoft docs. Also I made a bone model and material in a blender and exported them to obj and mtl files.

Sources can be found here in my blog (in Russian)

I made an Pulse Induction metal detector for myself.
It was a good challenge for me and I did it! During the creation of this device, I went through the following steps:

1. Designing the electrical circuit in the proteus. I coped with this quickly and without much difficulty.
2. Converting an electrical circuit to a PCB drawing. There were no difficulties with this either.
3. Transfer of PCB pattern onto fiberglass coated with copper foil. I used a photoresist here. With the help of an ultraviolet lamp and a special film, I got a PCB drawing.
4. Etched copper with copper sulfate and salt.
   • Here the first difficulty arose – the tracks were too thin, and some of them were damaged. I slightly changed the PCB pattern, made the tracks wider, repeated the transfer of the pattern to the foil-coated fiberglass, after which the board turned out to be excellent!
5. Drilled holes in the right places
6. Soldered all the necessary components
7. Made a coil.
   • (Here it was necessary to very accurately withstand all the dimensions, the number of turns, the cross-section of the copper wire. There were no difficulties here. After the coil was formed, I filled it with two-component epoxy resin and reinforced it with fiberglass for rigidity)
8. Developed software.
   • First, I created a program that periodically generates pulses of the required length to check the operation.
   • Using an oscilloscope, I picked up the resistor on the PCB to maximize the efficiency of the device
9. Modified and optimized the firmware. It came out not at all great, but effective.
   • Here the only difficulty was the low performance of the Arduino, it was necessary to check the speed of performing individual operations in microseconds so that all pulses were formed of a given length and frequency.
10. The device is ready

Here is a link to some device diagrams and a sketch (in Russian).

I did this project as a handy reference for finding the causes of failure of computers and peripherals. The first version was created in 2014, then I completely rewrote the program somewhere in 2018, made it more universal.

When redeveloping the application, I set myself the goal of creating a reference that can be updated without modifying the code. There were no particular difficulties in this, because the interface elements in the application are the simplest. As a result, I achieved what I wanted – the application forms the menu and interface are only based on information from the database.

To add new tabs and menu items, I no longer need to change the application code. It is enough to add the corresponding records to the database tables.

You can see how the first version of the project looked here

The current version of the project in google play