Nikita Rumyantsev
Offer Nikita work on your next project.
Private message 
Offer work 
Lvov,
Ukraine
currently online
responds within a couple of hours
available for hire
4 Safes completed
6 months 28 days back
5 clients
25 proposals made
on the service 3 years
Rating
Language proficiency level
Українська: fluent
Русский: fluent
English: upper-intermediate
Skills and abilities
Programming
- AI & Machine Learning
- AR & VR Development
- Bot Development
- C & C++
- C#
- Data Parsing
-
Databases & SQL
from 5 USD for hour
- Desktop Apps
-
HTML & CSS
from 3 USD for hour
- Java
- Javascript and Typescript
- PHP
-
Python
from 6 USD for hour
- Testing & QA
-
Web Programming
from 6 USD for hour
Portfolio
-
451 USD Room Linking Engine (Enterprise Business Process Automation via
AI & Machine LearningHigh-tech backend service for automating complex, multi-stage business processes of matching, linking, and synchronizing entities (rooms, real estate objects, or business units) between various providers and internal systems. The heart of the system is an autonomous AI agent based on LangGraph, which manages non-linear workflows (stateful workflows), dynamically makes decisions based on context, and processes business anomalies.
Key features and implementation:
… Stateful Multi-Agent Workflows (LangGraph): The logic of complex business processes is broken down into cyclic graphs with clear state preservation. The agent is capable of making decisions at forks (conditional routing), initiating retries (retry loops), and involving a human for verification when necessary (Human-in-the-loop).
Intelligent data matching: The AI agent analyzes unstructured or partially matching data from various providers (names, descriptions, metadata) and links them into a single entity with high accuracy, eliminating duplicates.
Asynchronous architecture with high fault tolerance: Built on Python and FastAPI using background tasks, allowing the system to process thousands of linking requests in parallel without blocking the main thread.
Validation and data integrity: Strict business rule control is implemented at every step of the graph, ensuring 100% data consistency before writing to the database.
Technology stack: Python • FastAPI • LangGraph • LangChain • PostgreSQL • LLM Function Calling • Pydantic (Data Validation).
-
1675 USD Gamified Habit Tracker.ai
AI & Machine Learning
Fully functional web application (MERN stack) for habit tracking that combines gamification tools and artificial intelligence algorithms to enhance individual productivity. The platform transforms routine goal monitoring into an interactive gaming process, encouraging user regularity through a reward system.
Technical and functional features:
… Gamified logic: Implementation of XP (experience) mechanics, continuous streak counters, and dynamic progress levels.
AI analytics: Generation of personalized recommendations and predictive analysis of user behavioral patterns based on AI models.
Data Visualization: Interactive dashboard with flexible graphs for detailed visualization of daily and long-term statistics.
Security and architecture: Reliable user authentication using JWT and storage of personalized data in MongoDB via REST API.
Development artifacts: The project is accompanied by comprehensive technical documentation (SRS and SDD) that details architectural solutions and system data flows.
Technology stack: MongoDB · Express.js · React · Node.js · REST API · JWT · AI Integrations.
-
999 USD Automatic article writing system
AI & Machine Learning
I designed and implemented a fully autonomous content creation and distribution system that requires no human intervention. The solution suite independently retrieves the specifications from Google Sheets, generates SEO-optimized material through OpenAI GPT, formats it, and publishes it on target resources.
Workflow algorithm:
… Input data: Topic, description, and platform are recorded in Google Sheets.
Generation: The n8n script passes the data to OpenAI GPT to create structured content.
Distribution: The finished article is automatically published on the required website via API or browser automation tools.
Logging: The system updates the status in the table, adding a direct link to the publication and the date.
Evolution of processes and metrics:
Previously, creating and manually posting one article took 30–40 minutes, limiting productivity to 1–2 materials per day.
Results of automation:
The speed of content output increased by 95% (the entire cycle takes less than 10 minutes).
Production volumes scaled to 20–50 articles per day simultaneously on 12+ websites.
Manual labor has been completely eliminated, which has radically reduced the cost of content.
Technology stack: n8n, OpenAI GPT, Google Sheets, REST APIs, Airtop Browser Automation, Webhooks.
-
Personal portfolio website for a Fullstack developer
Web Programming
Design: A minimalist "dark mode" style has been chosen. A deep gray background combined with a bright red accent creates a strong, confident, and technological image.
Main screen: Instantly presents the specialist and their value proposition ("impressive and functional websites").
… Portfolio: A visually appealing and dynamic grid of works has been implemented, showcasing the diversity of the developer's projects (e-commerce, finance, fitness, etc.).
Functionality: A clean and user-friendly FAQ block in the form of an "accordion" has been created for answers to common client questions, which increases trust.
Conversion: The "Order the project" button is strategically placed and highlighted in color to encourage potential clients to get in touch.
-
150 USD Telegram bot for integration with CRM via API
Python
Created a Telegram bot in Python (aiogram) that receives and processes data from a CRM system via API. Implemented several useful features: automatic extraction of client information, database search, status updates, and sending messages directly from the bot.
The bot operates stably, has a user-friendly interface, and can easily adapt to other CRMs or tasks.
-
Telegram Bot in SendPulse
Bot Development
A multifunctional Telegram bot has been developed on the SendPulse platform.
Main functionality:
Integration with CRM: The bot is connected to an external CRM system. This allows for automatic retrieval and updating of the product catalog, always showing users the current assortment.
…
Forced redirect: A managed flow mechanism has been implemented, which directs the user to a mandatory step (for example, subscription or verification) before granting access to the main functionality of the bot.
-
"Tasteorama" — recipe platform
Web Programming
Create a convenient and attractive website where users can find, plan, and share recipes. The main focus is on intuitive search and filtering.
-
Landing for "GREEN.HARVEST"
Web Programming
Develop the main page for the organic vegetable basket delivery service. The website should convey freshness, premium quality, and ease of ordering.
-
Student forum on React + FastAPI
Web ProgrammingThe project is a modern web forum for students, where users can exchange information and discuss learning topics. The forum supports both registration and authorization, as well as an anonymous mode, allowing users to remain invisible or create their own account for a personalized experience.
Frontend: React, modern UI, user-friendly navigation
… Backend: FastAPI, request handling, secure data storage
Features: registration, anonymity, ability to write and read posts without an account
The project demonstrates full-stack development skills, including frontend and backend integration, working with APIs, and providing a flexible user experience.
Reviews and compliments on completed projects 4 1
5 November 2025
25 USD
LeadStream Bot – Integration of Telegram with CRM "KeyCRM" via API.
Quality
Professionalism
Cost
Contactability
Deadlines
Did everything well, without unnecessary questions. Competent in this field. I will cooperate in the future.
|
4 November 2025
34 USD
Module for monitoring new trading pairs on the exchange using the official API
Quality
Professionalism
Cost
Contactability
Deadlines
The work was completed on time and with quality. The communication of the performer is at a good level, always in touch, interested in the work, we found understanding very quickly. I recommend for collaboration.
31 October 2025
58 USD
Adaptive layout
Quality
Professionalism
Cost
Contactability
Deadlines
The project is completed, I made quite a few revisions, but everything was corrected.
Aleksandr Karadyaur
| Personal | Response review
31 October 2025
90 USD
Email mailing SendPulse Weblium Apix drive
Quality
Professionalism
Cost
Contactability
Deadlines
The freelancer took the job, said they would do everything. Additionally, I asked if they would manage it, right? I paid the money for the freelance work. The next day, the performer writes, I can't manage to do it. Zero responsibility.
Quality
Professionalism
Cost
Contactability
Deadlines
The project was done well and on time. Communication is excellent, I recommend!
Activity
| Projects underway 1 | Budget | Added | Deadlines | Proposal | |
|---|---|---|---|---|---|
|
Need a Minecraft 1.12.2 collector (tech assembly for Mohist)
99 USD
|