Андрій

Andrii Leshchenko Profile

Profile

I am a Full Stack Web Developer with a strong focus on backend development. I
have over 4 years of commercial experience, during which I have been involved
as a developer in 19 different projects. My primary tech stack includes: Frontend:
React and Vue.js Backend: Express and NestJS I also have solid experience
working with GraphQL. Although I am a JavaScript developer, I can effectively
communicate and collaborate with developers who work with PHP, C++, Flutter,
and other programming languages. I am capable of contributing to development
alongside them and, if needed, writing code in other languages. If there is a logical
Personal details abstraction, I have the understanding needed to translate it into code, even
outside of JavaScript. I am open to opportunities to work in a dynamic, forward-
thinking team with positive-minded developers.
Andrii Leshchenko

1. In my resume, I will include the 6 projects I am most proud of.
[open contact info](look above in the "contact info" section)

[open contact info](look above in the "contact info" section) Employment
22 43000 Full-Stack Developer Feb 2023 - Jun 2023
Mirko Solutions, Frankfurt
April 20, 1993 Medical Management Web Service

[open contact info](look above in the "contact info" section) Description: I was involved in a complex and fascinating project within the medical
domain, developing an extensive web service for personnel management, patient
data, inventory, and more. This project was specifically tailored for a network of

Skills clinics in the United States and stands out as one of the most challenging and
intriguing endeavors in my career.

3D models Role: Full-Stack Developer

AWS
Key Project Details:
API Development
Technology Stack:
API
Frontend: Vue.js Backend: Express, GraphQL Database: MySQL Deployment:
backend development Docker Security: Cryptography software Additional Skills Required:
Backend
Proficiency in C and C++ In-depth knowledge of the Ubuntu operating system
C++ Responsibilities:

CSS3 Data Encryption Integration:

SCSS
Integrated a custom encryption module into the project for securing sensitive data.
cron jobs Microservices Deployment for Cryptography:

D3.js Deployed six microservices for cryptography and configured seamless interaction
between them. Resolution of Technical Challenges:
Database Design
Successfully addressed complex technical challenges arising from software
Database
incompatibilities. Custom Cryptography System Development:
databases
Created a custom data cryptography system, handling encryption and mutation on
Docker
the backend. Implemented functionality for storing encrypted data in databases.
Express.js Developed corresponding features for data decryption.

Flutter Enhancements to Admin Panel:

Frontend
Introduced a new design and functionality to the admin panel on the frontend.
GraphQL Implemented diverse charts and graphs for displaying statistics related to the
medical facility's operations. This project demanded a diverse skill set, including
HTML5 expertise in cryptography, microservices architecture, and proficiency in
languages like C and C++. The successful integration of a custom cryptography
JavaScript system and the enhancement of the admin panel underscored the depth and
complexity of the project.
live chat
Full-Stack Developer Aug 2022 - Dec 2023
Microservices
Mirko Solutions
microservices architecture Virtual Apartment Galleries. Real Estate project Mirko Solutions Aug 2022 - Dec
2023 (1 year 5 months) Title: Real Estate Platform for 3D Apartment Listings
backend services
Description: This project aimed to create a platform where real estate sellers could
Mobile Application
showcase 3D models of their apartments for sale. As a backend developer on this
mobile app project, my responsibilities included the following:

MongoDB Backend Development from Scratch:

MySQL Developed the backend using NestJS, PostgreSQL, and TypeORM. Implemented
a registration system supporting three methods: email, phone, and Google
Nest.js
account. Integration of 3D Models:
NestJS
Integrated a third-party API for handling 3D models within the platform. Multi-role
Node.js Authorization and Authentication System:

PHP Designed and implemented a multi-role system for authorization and
authentication. Virtual Apartment Galleries:
payment gateway

PostgreSQL Developed a virtual gallery showcasing 3D apartments. Enabled users to take
virtual tours with the option to save coordinates of key locations to their accounts.
programming languages Checkpoint Functionality:

Redux
Implemented functionality allowing users to save checkpoints during virtual
React.js apartment tours. Admin Panel Creation:

React Developed an admin panel for managing platform content and users. Database
Design and Implementation:
Stripe
Designed and implemented the database structure for the project. This
SASS
comprehensive approach resulted in a dynamic platform that not only facilitated
System Development the listing of 3D apartments but also provided users with interactive features such
as virtual tours, checkpoint saving, and a user-friendly administrative interface.
TypeScript
Full Stack Developer Jul 2023 - Oct 2024
Ubuntu operating system Surrogacy, Луцьк
Medical Clinic Web Platform with Flutter Application Duration: July 2023 - June
Authentication 2024 (1 year)Role: Full-Stack Developer Project Overview: This project involved
the development of a multifunctional platform for a medical
Vue.js

web application clinic. It enabled patients to search for donors and doctors, schedule
appointments, communicate through live chat, and conduct video consultations.
Web Platform
The platform also provided a system for purchasing paid services, powered by
web client Stripe integration. Additionally, administrative panels were developed for donors,
administrators, and clinic staff. A unique feature was the custom-built video chat
Web Service system with advanced room management by the administrator. Technology Stack:
Frontend: React, Redux, Redux-Saga, Redux-Thunk, SASS, Socket.io, Socket.
WebRTC
io-client, PeerJS, Axios Backend: NestJS, Stripe, PostgreSQL, Socket.io,
WebSockets WebRTC, Passport, Nodemailer Mobile: Flutter My Responsibilities on
projects and Key Contributions: Video Chat Development: Designed and
commercial experience implemented a video chat system from scratch using WebRTC and
WebSockets. Created a unique management system, allowing the room
effectively communicate administrator to control the video chat interactions. Real-Time
Communication: Built live chat functionality with WebSockets for seamless
communication
patient-doctor interaction. Implemented video consultations using WebRTC
forward-thinking with robust backend support. Administrative Panel Development:
Developed admin panels for donors, clinic administrators, and personnel to
friendly manage interactions and appointments. Patient Services Management:
Integrated Stripe payment gateway for purchasing services and handling
transactions. Implemented functionalities for booking and scheduling
Languages appointments with doctors and donors. Mobile Application: Contributed to
the development of a Flutter-based mobile app, offering patients an alternative
English way to interact with the platform. Backend API Development: Created a
scalable backend using NestJS and PostgreSQL, ensuring smooth interactions
between the mobile app, web client, and backend services. Team Structure:
Worked in a collaborative team of 5 developers, contributing to both frontend
and backend development. This project highlighted my ability to handle complex
video communication technologies, payment integrations, and the development of
real-time features across web and mobile platforms.

Full-Stack Developer Apr 2022 - Jul 2023
Under NDA, Detroit
Migration of an E-commerce Site and Admin Panel for an American
CompanyDescription: Project for a Detroit-based American company specializing
in auto parts sales. I was responsible for migrating a complex, extensive database
from a 1988 MySQL structure to PostgreSQL, porting the backend from PHP to
NestJS, and almost completely rewriting the frontend in React to meet updated
design requirements. Responsibilities: Porting and upscaling from the old
technology stack to a new, modern one Developing new functionality in the
admin panels GUI development using React and Redux

Expanding the old database for new functionalities and migrating it to a more
modern query structure Managing extensive and complex backend email
distribution through cron jobs Direct communication with the American client,
conducting all interactions in English Understanding client requirements,
engaging effectively to grasp the business context, and ensuring alignment with
the client's vision and goals Main Technologies: SASS, React, Redux, AWS,
NestJS, PHP, MySQL, PostgreSQL, TypeORM

Backend Developer Jan 2021 - Aug 2021
Bucharest
A web application designed to manage the entire construction process. The
platform facilitated management of all workflows, enabled employee chat
functions, and allowed event planning. It featured a complex, custom-built system
for administrators and managers, each with unique access permissions.
Country: Romania Position: Backend Developer Responsibilities: Expanding
the functionality of the existing API Collaborating closely with frontend
developers Designing and implementing the database structure Developing a
unique API for analysts to scan the project database, generate summaries, and
produce Word documents with charts and comprehensive statistics on the
entire construction project for efficient project management Duration: 7
monthsCommunication: The team was fully English-speaking, and communication
was handled through Slack. Main Technologies: Frontend: React, Redux, Chart.
js, D3.js Backend: NestJS, PostgreSQL, TypeORM Tools: Docker, docx

Backend Developer/Frontend Developer Sep 2020 - Jul 2022
Cruspher, Львів
This is a sports platform where users can make predictions on matches, integrate
cryptocurrency, and access a ranking system for platform users. It also features
chat rooms for discussions and a blog with sports news. I have permission to
openly state that I was a developer for this project, so I’m including the link to the
platform:https://www.cruspher.com/
My responsibilities on the project included:
Developing the backend and database from scratch.
Implementing the logic for sports predictions on matches and various games.
Building a fast and reliable API, integrating third-party APIs on the backend.
Creating email notifications for users.
Deploying the project.
Partially completing frontend tasks.
Main technologies of the project: React/Redux, Socket.io, NestJS, TypeORM,
PostgreSQL.
Additionally, during the creation of this platform, I obtained an international
inventor's certificat