Logo
Ostap – React, Node.js, PHP, experts in Lemon.io

Ostap

From United States (UTC-4)

flag
Full-stack Web DeveloperSenior
Tech lead
14 years of commercial experience
Agritech
AI
Analytics
Art and creativity
Consulting services
Data analytics
Disaster management
E-commerce
E-learning
Edtech
Govtech
Healthcare
Healthtech
Human resources
Job and career services
Legal tech
Logistics
Management
Manufacturing
Marketing
Medtech
NFT
Public services
Retail
Social impact
Social media
Supply chain
Travel
Nonprofit
AI software
Communication tools
Enterprise software
ERP
LMS
Mobile apps
No-code software
Platforms
SaaS
Video streaming software
Lemon.io stats
10
projects done
3874
hours worked
1
offers now 🔥

Ostap – React, Node.js, PHP

Look no further in your search for the finest full-stack developer because Ostap is here. Passionate about JavaScript he can build architecture from scratch without hesitation. With rich expertise in the IT industry, complemented by recent AI experience and numerous successful projects under his belt, Ostap brings a strong CTO and backend background, making him adept at solving complex tasks.

Main technologies
React
5 years
Node.js
4 years
PHP
6 years
JavaScript
7 years
Next.js
4 years
Typescript
4 years
Additional skills
MySQL
MongoDB
Express.js
AWS
WordPress
Python
Laravel
Tailwind CSS
Nest.js
Prisma
GCP
Twilio API
Vercel
PostgreSQL
Google Analytics
Docker
Shopify
Firebase
Redis
OpenAI API
Chart.js
Supabase
LangChain
Mistral LLM
Rewards and achievements
Client's favourite
Swift communicator
Testimonials
#14520321336Strong Senior Front-end developer | React / Next.js, full-time, 3 months, Australia
"Ostap has worked tirelessly over the December and January period with me on a special project for a partner of ours, and he is an absolute rockstar!!! "
Ready to start
May 22
Direct hire
Potentially possible
Ready to get matched with vetted developers fast?
Let’s get started today!

Experience Highlights

AI Systems Architect & Full-stack Developer
Feb 2025 - Apr 20252 months
Project Overview

An emotionally intelligent system built to power brand experiences through poetic, symbolic interaction. It merges local language models with evolving memory and emotional recall, enabling deep personalization for wellness, fashion, and immersive storytelling applications.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Developed vector memory engine with Mistral + Weaviate for personalized recall;
  • Built resonant interaction layer using symbolic inputs and emotional cues;
  • Designed modular personas and frontend experience with Next.js + Supabase;
  • Enabled emotional brand alignment through state-aware memory traces.
Project Tech stack:
Mistral LLM
LangChain
Weaviate
Typescript
PostgreSQL
Supabase
Vercel
Tailwind CSS
OpenAI
OpenAI API
GPT-4
DigitalOcean
Full-stack Developer / Data Engineer
May 2024 - Feb 20259 months
Project Overview

A large-scale healthcare platform serving users across the USA and Canada. The platform connects patients with medical services and clinical trials, offering personalized communication and advanced data processing.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Built a high-performance caching solution to process over 500,000 data points per week for complex statistics using BullMQ queueing;
  • Managed weekly delivery of 200,000+ personalized emails, incorporating dynamic charts (pie, line, bar) and geospatial maps;
  • Developed automated patient appointment reminders via SMS and email;
  • Engineered a system to gather post-appointment reviews, transforming and anonymizing client data using LLMs (OpenAI).
Project Tech stack:
Next.js
Chart.js
Redis
Redux
AWS
Cloudflare
PostgreSQL
Twilio API
OpenAI API
Prisma
AI
Full-stack Developer
Nov 2022 - Jan 20252 years 2 months
Project Overview

A public-facing platform developed for a regional government in Ukraine to display open data, statistics, and performance ratings of municipalities. The system includes visualizations (charts, maps), public service information, and an admin panel for managing content and configurations.

Multiple development iterations through 2022–2025

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Designed and implemented full-stack architecture using Next.js and NestJS;
  • Integrated APIs from other government services to import real-time community data;
  • Configured server deployment and CI/CD pipelines using Vercel and Railway;
  • Built interactive dashboards showing community statistics, development metrics, and rankings;
  • Developed an admin panel for managing datasets and publishing updates;
  • Added module for public medical institution listings, including searchable directories and statistical overviews;
  • Implemented email services using Mailgun for admin alerts and public data export requests.
Project Tech stack:
Next.js
React
Nest.js
Tailwind CSS
Prisma
MySQL
Front-end Developer
Oct 2023 - May 20246 months
Project Overview

Project 1: Dynamic Form SaaS Platform ("ReFRMD")

A rebuilt and extended SaaS application enabling users to create highly dynamic, conditional forms adaptable across industries (e.g., agriculture, risk management). Designed to gather complex input data and feed into a reporting and analytics system.

Project 2: Product Presentation Platform for Tablets

A SaaS tool for merchants to present custom product information (e.g., intraoral scanners) via tablet-based apps, with an admin panel for presentation creation and international customization.

Skeleton
Skeleton
Skeleton
Responsibilities:

Project 1: Dynamic Form SaaS Platform ("ReFrmd")

  • Migrated frontend architecture from React to Next.js;
  • Developed complex dynamic form engine with conditional logic and reusable subforms;
  • Implemented JWT-based user authentication and user management features;
  • Integrated with existing APIs shared with mobile app clients;
  • Built customizable reporting views and analytics models for submitted form data.

Project 2: Product Presentation Platform for Tablets

  • Built responsive tablet-oriented layouts for dynamic slide presentations;
  • Developed admin dashboard to create, manage, and reuse branded presentation slides;
  • Implemented multilanguage support and country-specific settings (including data restrictions);
  • Integrated the platform with corporate app hosting environments for deployment of customized builds.
Project Tech stack:
React
Next.js
i18next
Tailwind CSS
CSS
Material UI
ChakraUI
Vercel
Front-end Developer
Dec 2023 - Apr 20243 months
Project Overview

A web system for managing loading and unloading cargo ship containers for a major logistics company. The platform includes tools for ship crews to register containers during operations, as well as management features for reporting, legal documentation, and process oversight.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Designed and implemented the frontend architecture using React.js and Tailwind CSS;
  • Integrated frontend with backend services and legacy system APIs;
  • Developed dynamic forms for ship crews based on ship codes and cargo specifications;
  • Implemented Supabase-based user authentication and access control;
  • Created frontend logic for generating various PDF documents (reports, legal paperwork);
  • Ensured responsive design and usability across roles (crew and management).
Project Tech stack:
React
Typescript
Supabase
Tailwind CSS
React Hooks
Vercel
Vercel Postgres
Front-end Developer
Mar 2023 - Jul 20234 months
Project Overview

A centralized platform aimed at helping asylum seekers and refugees in Canada understand their rights and access essential services and legal resources.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Implemented new front-end features based on evolving user needs and accessibility standards;
  • Integrated the front end with an existing backend API, ensuring data consistency and UI responsiveness;
  • Diagnosed and resolved critical bugs across multiple components;
  • Ensured accessibility and compatibility across devices for a vulnerable user base.
Project Tech stack:
React
MobX
Tailwind CSS
Material UI
Full-stack Developer
Aug 2022 - Nov 20222 months
Project Overview

A SaaS platform designed to connect nurses with professional coaches, enabling secure video communication and appointment scheduling.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Designed and implemented both frontend and backend architecture from scratch;
  • Set up and configured backend servers for production deployment;
  • Integrated Mailgun for transactional email functionality;
  • Built core user flows including nurse-coach matching and video session support;
  • Delivered a stable MVP on a tight deadline after a previous version failed to meet quality standards.
Project Tech stack:
React
Typescript
Prisma
Twilio API
Nest.js
MySQL
GCP
Front-end Developer
Mar 2022 - Jul 20224 months
Project Overview

An AI-driven portfolio platform that helps students showcase their strengths by aligning skills with real evidence, building credibility and visibility through a smart, skills-based portfolio.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Implemented modern, responsive frontend modules based on Figma design mocks;
  • Debugged and refactored legacy frontend code to improve stability and maintainability;
  • Collaborated closely with backend developers to ensure smooth API integration and feature delivery;
  • Enhanced UI consistency and user experience across portfolio-building flows.
Project Tech stack:
React
Tailwind CSS
Next.js
Lead Developer
Sep 2021 - Apr 20227 months
Project Overview

SaaS learning platform designed to help startups create educational content, assign personalized learning paths, and track real-time training performance and engagement metrics.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Developed full-stack architecture, covering both frontend and backend systems;
  • Set up server infrastructure and deployment pipelines using Railway and Vercel;
  • Integrated external services, including Notion API and Mailgun, to enhance content workflows and communication;
  • Delivered a modular, scalable platform adaptable to various startup needs.
Project Tech stack:
Nest.js
React
Tailwind CSS
PostgreSQL
Prisma
Vercel
Full-stack Developer
Aug 2021 - Dec 20214 months
Project Overview

A DeFi platform that builds distributed asset pools for player-owned economies, allowing NFT holders to earn passive income and contribute to a circular crypto economy. The platform lowers the barrier to entry for millions exploring crypto and the Metaverse.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Developed and maintained both frontend and backend features across the platform;
  • Rewrote critical business logic previously written in Python, migrating it to the TypeScript ecosystem;
  • Wrote unit tests and ensured feature stability;
  • Participated in team code reviews and managed PR quality;
  • Helped synchronize frontend-backend API flows in a real-time web3 environment.
Project Tech stack:
Nest.js
Next.js
i18next
React
Prisma
Vercel
Typescript
PostgreSQL
TypeORM
Tech Lead
Feb 2021 - Sep 20217 months
Project Overview

A specialized video-based coaching platform where medical professionals can improve their communication skills. Doctors engage in interactive training sessions with standardized patients (actors), who provide structured feedback on performance, simulating real-life consultations.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Led full-stack development efforts and mentored junior developers throughout the project;
  • Designed and implemented critical frontend and backend features for real-time video sessions and feedback workflows;
  • Wrote and maintained test suites; prepared internal documentation for future developers;
  • Managed code quality through peer reviews and technical planning;
  • Developed modules for coaches and doctors, performance analytics, and actor review tools.
Project Tech stack:
React
Nest.js
Tailwind CSS
Node.js
MongoDB
MongooseODM
Lead Developer
Aug 2019 - Apr 20211 year 7 months
Project Overview

A large-scale ERP system developed for Syngenta Corporation, a global leader in agricultural science and technology. The system supports decision-making and operations for agriculture professionals by integrating weather data, crop management tools, and enterprise systems.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Developed and maintained a complex ERP system with over 80 interrelated data models and tens of millions of records in the database;
  • Implemented bidirectional integration with Syngenta's global corporate ecosystem;
  • Integrated with Meteoblue, a global weather data provider;
  • Established two-way sync with Cropio, a crop and field management system;
  • Built support for 7 user roles with customized permission levels;
  • Contributed to the development of 10+ functional modules, including analytics, logistics, and agricultural task planning.
Project Tech stack:
Laravel
PHP
PHPUnit
React
Axios
CSS
HTML
Lead Front-end Developer
Nov 2020 - Apr 20214 months
Project Overview

An AI-powered platform for visual content analysis, providing advanced tools for analyzing images and video content at scale. It serves use cases in retail, advertising, and media with data-driven visual intelligence.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Developed and optimized frontend components using React.js;
  • Worked closely with design and AI teams to implement dynamic UI components;
  • Contributed to building a smooth and responsive user experience for data-intensive interfaces;
  • Ensured performance and compatibility across devices and browsers.
Project Tech stack:
React
CSS
HTML
Full-stack Developer
Aug 2020 - Mar 20217 months
Project Overview

A niche B2B/B2C marketplace designed for the German precious metals market. It enables seamless trading of metals with real-time pricing, multi-role access, and integrated payment systems.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Developed user panels for various roles: admin, operations, vendors, and customers;
  • Integrated real-time price feeds from metal pricing providers;
  • Implemented secure payment gateway support via PayPal and Stripe;
  • Set up Gmail-based authentication for streamlined user onboarding and login;
  • Ensured smooth UX and operational workflows for both buyers and sellers.
Project Tech stack:
Laravel
PHP
PHPUnit
MySQL
ORM
Stripe API
CSS
HTML
Tech Lead and Co-founder / CTO
Jul 2017 - Dec 20181 year 5 months
Project Overview

A platform designed to connect startups with the right talent and investors in the Nordic ecosystem. The platform became a major hub for startup hiring and visibility — and was later acquired by TheHub.io, expanding its impact in the region.

Skeleton
Skeleton
Skeleton
Responsibilities:
  • Led the development and implementation of a long-term technical roadmap;
  • Built internal processes and workflows for a growing development team;
  • Oversaw technical development from architecture to deployment;
  • Managed both local and remote development teams;
  • Prepared technical presentations and investor reports;
  • Participated in public presentations and startup events;
  • Recruited, interviewed, and grew the internal tech team.
Project Tech stack:
JavaScript
Node.js
React
Restify
MongoDB
MongooseODM
Socket.io
Webpack
Google Analytics
npm

Education

2011
Computer Science
Master's
2013
Master of Engineering (M.Eng.), Ingeniería informática
Master
2015
Master’s Degree, Global E-business
Master

Languages

French
Pre-intermediate
Polish
Advanced
Spanish
Intermediate
English
Advanced

Hire Ostap or someone with similar qualifications in days
All developers are ready for interview and are are just waiting for your requestdream dev illustration
Copyright © 2025 lemon.io. All rights reserved.