Denis Z.
Private message 
Kharkiv,
Ukraine
available for hire
Rating
Language proficiency level
Українська: fluent
Русский: fluent
English: advanced
Skills and abilities
Programming
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Bot Development
from 17 USD for hour
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Databases & SQL
from 17 USD for hour
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HTML & CSS
from 12 USD for hour
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Javascript and Typescript
from 17 USD for hour
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Testing & QA
from 17 USD for hour
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Web Programming
from 17 USD for hour
Services
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Online Stores & E-commerce
from 17 USD for hour
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Payment Systems Integration
from 17 USD for hour
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Tuition
from 17 USD for hour
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Website Development
from 17 USD for hour
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Website Maintenance
from 17 USD for hour
Mobile development
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Hybrid Mobile Apps
from 17 USD for hour
Portfolio
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226 USD Kinesiology
Web Programming
multi-page website
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1200 USD CRM WATER
Web Programming
the project is implemented in Python and React
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1200 USD Fary GPT
Web Programming
#gpt4 #GPT #React/TypeScript #express.js #Node.js
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1500 USD CLIX AGENCY
Web Programming
#Next.js #React/TypeScript #PostgreSQL
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1500 USD TripTopCar
Web Programming
Project: Car rental website in Phuket with integrated CRM system.
Technologies:
… Next.js for server-side rendering and SEO optimization.
TypeScript for code typing.
PostgreSQL and Prisma ORM for database management.
Tailwind CSS for interface styling.
Stripe API for payment processing.
Description:
A website has been created for car rental with functionality for searching, booking, and fleet management. An integrated CRM system for managing orders and customer data. The project includes integration with the Stripe payment system and optimization for search engines.
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300 USD QA Portfolio
Web Programming
As part of creating a personal portfolio website, I implemented a unique interactive 3D visualization using the GLB format to display various objects and models. Libraries such as Three.js and React were used for rendering and interacting with 3D resources, allowing for a dynamic and engaging presentation of projects and works.
Key technologies:
… React: The main framework for developing the interface and managing the page state.
Three.js: A library for creating and rendering 3D objects in the browser.
GLB: A 3D model format used for loading and displaying objects with textures and animations.
Implemented tasks:
Interactive 3D visualization:
Integration of 3D models in GLB format to create impressive and realistic objects that can be rotated and explored.
Application of animations and textures for models to make the interface more lively and interesting.
Rendering with Three.js:
Using Three.js to build a 3D scene with proper lighting, cameras, and effects.
Setting up user interactions such as rotating models, zooming in/out, and moving objects, allowing website visitors to engage more deeply with the content.
Development with React:
Development of website components in React with dynamic content updates and 3D objects, considering user actions.
Integration with React for state management and ensuring a smooth user interface.
Performance optimization:
Optimization of model loading and rendering, which improved website performance, especially when loading more complex 3D objects.
Testing on different devices and browsers to ensure maximum compatibility.
Responsive design:
Application of responsive design so that the website displays correctly on both mobile devices and desktops, taking into account the specifics of 3D graphics visualization.
Result:
The portfolio website was successfully developed with a unique 3D experience that allows clients and visitors to get a deeper understanding of the projects and works. Thanks to the use of modern technologies, the website is lightweight, fast, and interactive. All 3D objects are displayed correctly in the browser, and the application's performance has been optimized for comfortable use on various devices.
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1000 USD E-COMMERCE WEBSITE
Online Stores & E-commerce
This project is a responsive device catalog built with React.
React, React-router, Sass (SCSS), Mobile First, TypeScript
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1000 USD CRM for car rental
Web Programming
Project: CRM system for a car rental website
For this project, a CRM system was developed to manage car rentals, with a particular focus on preserving the profits of vehicle owners. The system simplifies interaction between clients and landlords, minimizing the risks of losses and ensuring more efficient management of business processes.
… Key technologies:
Next.js: used to create a high-speed and user-friendly web application that provides clients and administrators with a convenient interface.
PostgreSQL: a reliable database for storing information about orders, cars, clients, and payments.
Prisma: a tool for working with the database, simplifying the creation of queries and migrations.
Project features:
Order management: administrators and owners can effectively track current and future rentals, as well as maintain up-to-date information on car availability, preventing missed rental opportunities.
Payment accounting automation: the system allows for accurate tracking of financial flows, reducing the risks of calculation errors and financial losses.
Loss protection: through integration with the booking management system, car owners can ensure timely payment and avoid situations with unclaimed rentals or unacceptable delays.
Admin panel: access to comprehensive reports and analytics helps business owners respond more quickly to changes, increasing operational efficiency and ensuring stable income.
Results:
The system allows car owners to effectively manage their fleet and minimize losses associated with unscrupulous renters or underutilized vehicles. This ensures income stability and optimization of business processes, guaranteeing owners a high level of protection and convenience.
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500 USD Listen to the story
Bot Development
We developed an application for Telegram that allows users to search, purchase, and listen to audiobooks.
Technologies and functionality:
Backend: Development of the server side in Java using Spring Framework to ensure high performance and scalability. An API has been implemented for interaction with clients and secure payment processing.
… Frontend: An interface has been implemented in React, which integrates with Telegram Web Apps, providing users with convenient access to the audiobook catalog, shopping cart, and transaction history.
Key features:
Book catalog with filters and search.
Ability to add books to favorites and the cart.
Support for purchasing books with payment system integration.
Built-in audio player for listening to purchased books.
Integration with Telegram: The application fully operates within Telegram, using its Web App API for authorization and user interaction.
Project features:
Optimized interface for mobile devices.
Implementation of user data and transaction protection.
Support for updates and integration of new features in the future.
The project is focused on creating a comfortable user experience, offering quick access to audiobooks directly in Telegram.
Reviews and compliments on completed projects 26
4 May
322 USD
Сайт для Дайвинг Центров: API интеграция (v1)
A good specialist, we will continue to collaborate.
23 March
605 USD
Website for Diving Centers: Latest Pages
A good performer, we will continue working.
12 March
293 USD
Website for Diving Centers: Front Page
The developer is responsible and completed everything on time.
17 February
199 USD
Website for Diving Centers: Next Stage
A good performer, we continue to work.
9 February
126 USD
Diving Center Website: Centers
Well done work, we continue cooperation.
3 February
145 USD
Website: React.JS / Next.JS / TypeScript
Good performer, we will continue working.
24 January
622 USD
Roles + subscription for online monitoring
Everything is done on time. We recommend the specialist.
30 December 2025
466 USD
Layout of pages without dynamic data for the vending equipment monitoring system based on Chinese API.
Thank you, everything is correct, prompt, and even with bonuses.
14 August 2025
462 USD
Stage 0.3
Thank you for the work. We continue to collaborate further.
22 July 2025
690 USD
Connecting the layout to the backend
Thank you for the work, the project is completed
15 July 2025
120 USD
NextJS and layout - urgent
The work was done excellently! Quickly and with quality.
9 July 2025
33 USD
OpenAI Model Tuning & Prompt Engineering Consultation
A good specialist, completed the work qualitatively and professionally. I recommend for cooperation.
24 June 2025
564 USD
Stage 0.2
Worked with the contractor on the second stage of startup development — the result exceeded expectations. All tasks were completed with quality, understanding of project details, and adherence to deadlines. The specialist is responsible, always available, open to edits and suggestions. Communication was easy and productive.
It was especially pleasant to see initiative — the freelancer not only performed the technical task but also proposed successful solutions that improved the overall logic and functionality of the product.
I recommend for collaboration! I will gladly turn to them again for the next stages of development.
23 June 2025
700 USD
React + Next.js layout
Thank you for the completed work
15 June 2025
113 USD
Simple online store
We are very lucky to work with Denis. He did a great job! The store looks exactly as we wanted – everything is beautiful, convenient, and works as expected. Communication is top-notch, all wishes are taken into account, and any questions are resolved quickly. We are very satisfied with the result.
8 June 2025
34 USD
Development of a landing page with a shopping cart
Excellent work done considering all requirements, I recommend for collaboration
29 May 2025
61 USD
Refinement of the minivan website
The work was completed on time and strictly according to the specifications
26 May 2025
609 USD
Develop a Telegram bot with a WebApp (mini-application)
Worked with this programmer on developing a Telegram bot — overall, I was satisfied with the result. Tasks were completed on time, and everything was technically well implemented. I was especially pleased that he responded quickly to edits and was in touch. The only wish — I would like him to test the functionality more himself before sending it for review, so as not to spend time on revisions due to minor flaws. Otherwise — an excellent specialist, I recommend!
23 May 2025
34 USD
Turnkey Landing Page
Everything on time, everything stylish. Recommendation!
20 May 2025
425 USD
Stage 0.1
The project stage has been successfully completed. We continue our cooperation.
| Response review
3 May 2025
113 USD
Stage 0.1 Simple
Working with Denys left only positive impressions! The task was completed qualitatively, on time, and taking into account all wishes. The specialist demonstrated a high level of professionalism, responsibility, and communication skills. I especially want to note the promptness in communication and a flexible approach to edits. The result exceeded expectations. I recommend collaboration and will definitely contact again!
24 April 2025
158 USD
Layout of the website according to the Figma mockup (clean code, responsiveness)
Thank you very much for the work done!
Great communication, the work was done with quality and enthusiasm.
I recommend!
16 March 2025
61 USD
Web Developer (White Page sites for Google PPC)
the project was completed on time. everything is ok
11 March 2025
41 USD
Trust to create blocks and pages for the website
Everything is fine, all tasks and comments have been completed.
24 February 2025
609 USD
Frontend Development of CRM on React
Everything is fine. It would be good if Denis checked the work himself more thoroughly before sending it to the client.
2 February 2025
45 USD
Improvement and support of the project on ReactJS (NextJS)
Quick approach to solving the problem, thank you
Activity
| Projects underway 2 | Budget | Added | Deadlines | Proposal | |
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Website for Diving Centers: Shopping Cart and Home Page Updates
145 USD
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Сайт для Дайвинг Центров: API интеграция (v2)
322 USD
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| Latest proposals 10 | Budget | Added | Deadlines | Proposal | |
|---|---|---|---|---|---|
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A turnkey website for wedding photographers: design + text + launch
609 USD
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Telegram Bot RPG
609 USD
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Website for booking and viewing tourist destinations
609 USD
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Create a one-page landing page for a single product.
23 USD
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Development of 2 chatbots for mini-courses
176 USD
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Development of 2 landing pages for mini-courses on hair and scalp care
180 USD
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A bot needs to be created in Telegram for subscription payment.
45 USD
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Development of an online store
401 USD
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Full-stack development
800 USD
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Westmount Clinic
253 USD
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