Ihor is available for hire

Ihor Romanchuk

Verified Expert in Engineering

Software Developer

Location

Kraków, Poland

Toptal Member Since

March 18, 2020

Ihor is an experienced senior full-stack web developer with a strong track record of delivering quality products. Proficient in multiple technologies, he excels in crafting custom projects, making informed architectural decisions, and managing databases, back ends, front ends, cloud hosting, CI/CD, and more. Currently, Ihor focuses on front-end development using React, TypeScript, and JavaScript. His dedication and adaptability make him a valuable asset for any project.

Back-end Web Development Front-end Full-stack User Experience (UX)User Interface (UI)Algorithms Multithreading UI Components Customer Relationship Management (CRM)React Hooks ESLint UI Libraries RDBMS Visual Studio

Portfolio

Realtyshoot

Stripe, NestJS, React, TypeScript, Prisma, Docker, Amazon Web Services (AWS)...

Digible Inc.

Node.js, NestJS, PostgreSQL, JavaScript, TypeScript, TypeORM, Sequelize...

GeneDx

JavaScript, HTML5, CSS, .NET, React, TypeScript, MobX, AngularJS, SQL, Git...

Experience

CSS - 8 years C# - 8 years SQL - 8 years JavaScript - 8 years React - 5 years TypeScript - 4 years ASP.NET Core - 4 years Amazon Web Services (AWS) - 3 years

Availability

Full-time

Preferred Environment

Docker, Amazon Web Services (AWS), React, TypeScript, Node.js, C#, SQL

The most amazing...

...web service I helped develop is called JustAnswer. It required extensive, in-depth testing, refactoring, complex integrating, and creating bug-free solutions.

Work Experience

Senior Full-stack Developer

2023 - 2023

Realtyshoot

Developed an app that connects real estate owners with photographers and stagers. It lets them find and choose the photographer and schedule the photo session.
Fixed multiple problems including the broken Stripe integration.
Managed one mid-level front-end developer using Jira as a task management tool. Conducted regular code reviews.
Improved the development setup with a Docker Compose file for local development.

Technologies: Stripe, NestJS, React, TypeScript, Prisma, Docker, Amazon Web Services (AWS), Amazon S3 (AWS S3), JavaScript, CSS, HTML, Tailwind CSS, Monorepos, PostgreSQL, Node.js, SQL, REST, RDBMS, Vercel

Senior Node.js Engineer

2023 - 2023

Digible Inc.

Developed a minimum viable product (MVP) that automates content posting on Facebook and Instagram, enhancing content delivery efficiency.
Designed multiple content templates for Facebook and Instagram, enriching the MVP's capabilities for diverse posting needs.
Engineered a rule-based algorithm to generate new social media content, expanding automated content variety.
Refined TypeScript settings to enable null reference error checking, enhancing code robustness in the existing project.
Authored a comprehensive technical design document outlining the content-generation process, serving as a blueprint for future development and team member onboarding.
Automated the development workflow by setting up Github Actions, streamlining build and deployment processes during pull requests.
Standardized coding practices by configuring ESLint according to the Airbnb JavaScript Style Guide and fixed related errors.
Collaborated with cross-functional teams to gather requirements and feedback, ensuring the MVP aligned with organizational goals and user needs.
Conducted rigorous testing and debugging of the MVP, contributing to reliable uptime and minimal rollbacks on deployments.

Technologies: Node.js, NestJS, PostgreSQL, JavaScript, TypeScript, TypeORM, Sequelize, Google Cloud, GitHub, Axios, ESLint, UIBakery, Amazon Web Services (AWS), Minimum Viable Product (MVP), Architecture, Google Cloud Platform (GCP), Express.js, Postman, Full-stack Development, ECMAScript (ES6), REST, RDBMS

Senior Full-stack Developer

2022 - 2023

GeneDx

Completed a 1.5-year migration project successfully, transitioning from AngularJS to React with TypeScript.
Implemented new website layouts based on Figma designs, ensuring a modern and intuitive user experience.
Developed a comprehensive component library, adhering to Figma designs, for seamless integration into the website.
Reverse-engineered legacy code, enhancing maintainability and scalability by migrating it to a clean and efficient React codebase.
Expertly managed a complex ordering flow with multiple steps, sub-steps, and fields, including real-time validation and status tracking.
Implemented data persistence functionality, enabling users to reload the page without losing entered data, enhancing user convenience.
Integrated React application and standalone React components into the CRM system.
Successfully set up advanced event tracking using GA4 (Google Analytics 4) and designed a comprehensive technical schema leveraging GTM (Google Tag Manager) to optimize user experience insights and enhance digital strategy.

Technologies: JavaScript, HTML5, CSS, .NET, React, TypeScript, MobX, AngularJS, SQL, Git, GitHub, Storybook, Figma, Swagger, REST APIs, C#, ASP.NET, Google Analytics, Multithreading, Docker, Docker Compose, Webpack, Handlebars, Linux, Amazon Web Services (AWS), Minimum Viable Product (MVP), Architecture, OAuth, B2C, Postman, Full-stack Development, Customer Relationship Management (CRM), Integration, ECMAScript (ES6), SCSS, Headless Commerce, Google Analytics 4, Google Tag Manager, REST, RDBMS

Senior Front-end Developer

2021 - 2021

Unilever

Implemented the designs of several screens with pixel-perfect accuracy.
Adjusted Material UI components to the design appearance using the theming approach.
Introduced React development best practices to the project.

Technologies: React, TypeScript, MUI (Material UI), Jest, JSS, Design Systems, Git, Formik, Yup, Pixel Perfect, GitHub, Full-stack, Windows, Front-end, Web Development, HTML, Responsive Web Design (RWD), User Experience (UX), User Interface (UI), UI Components, Web Applications, UI Libraries, Component Libraries, Front-end Architecture, Front-end Development, CSS3, Minimum Viable Product (MVP), Architecture, Full-stack Development, ECMAScript (ES6), SCSS

Senior Full-stack Developer

2021 - 2021

Yara

Developed an app that helps farmers create crop nutrition plans. The app gives you a recommendation on when and how much fertilizer you should apply. Users can view data in different formats like tables and charts and share the plan as a link or PDF.
Built an app that helps farmers keep track of the farm's sustainability. It calculates the CO2 and N emissions levels compared to benchmarks and gives users improvement suggestions.
Conducted interviews for junior, mid, and senior positions.
Demoed new features to other teams and stakeholders.
Investigated the best graph library for the project, prepared comparisons with showcases, and presented them to the team leads.
Worked as part of the development team following the Scrum process. Conducted onboarding sessions for newcomers.

Technologies: React, TypeScript, JavaScript, Node.js, NestJS, GraphQL, Apollo, PostgreSQL, Docker, Amazon Web Services (AWS), CircleCI, Git, Design Systems, Styled-components, Microservices, Cypress, E2E Testing, Jest, React-Intl, Urql, Lodash, Recharts, React Hook Forms, ESLint, Visual Studio Code (VS Code), Axios, Sequelize, Puppeteer, Segment, Phrase, Charts, Figma, DevOps, GitHub, Full-stack, Windows, Front-end, REST APIs, Web Development, HTML, Next.js, Responsive Web Design (RWD), MERN Stack, API Integration, Architecture, APIs, User Experience (UX), User Interface (UI), UI Components, Storybook, Back-end, CI/CD Pipelines, Web Applications, UI Libraries, Component Libraries, Front-end Architecture, Front-end Development, CSS3, Multithreading, Express.js, Algorithms, Handlebars, Linux, Minimum Viable Product (MVP), Integration Testing, Postman, Full-stack Development, ECMAScript (ES6), SCSS, REST, API Gateways, RDBMS

Senior Full-stack Developer

2020 - 2020

ALLEYE

Implemented a web service called ALLEYE from scratch, helping organize and manage the instrument validation process in the health industry.
Prepared the architecture and implemented the website that consists of an ASP.NET Core REST API, a React SPA, and an SQL server database hosted in a dockerized Linux container on AWS.
Implemented features such as a dashboard with plenty of charts, audit trail, authentication and authorization with roles and permissions (using ASP.NET Core Identity and JWT), recurring jobs with Hangfire, and screen lockout after some time of inactivity.
Transformed the client's requirements into working solutions. Worked following the Scrum methodology, with daily scrums, grooming, planning sessions, and estimates, managing a small team of developers.
Configured CI/CD with test environment and auto deployments with Azure DevOps and AWS ECS.

Technologies: REST APIs, Visual Studio Code (VS Code), Database Design, Databases, HTML5, Swagger, AWS IAM, Cross-browser Compatibility, JSON Web Tokens (JWT), Data Visualization, Docker, Amazon Elastic Container Registry (Amazon ECR), Amazon Elastic Container Service (Amazon ECS), Amazon EC2, Amazon Web Services (AWS), Azure DevOps, Git, Lodash, Axios, React Router, Yup, Formik, React-Intl, MUI (Material UI), Recharts, CSS, JSS, HTML, JavaScript, TypeScript, React Hooks, React Redux, Redux, Single-page Applications (SPA), React, Code First, SQL, SQL Server 2017, Serilog, AutoMapper, FluentValidation, LINQ, Entity Framework Core, Hangfire, Identity, MediatR, ASP.NET Core, .NET Core, C#, REST, Charts, DevOps, T-SQL (Transact-SQL), Visual Studio, Full-stack, C#.NET, .NET, Windows, SQL Server Management Studio, Front-end, Web Development, AWS Lambda, Figma, Responsive Web Design (RWD), API Integration, Architecture, APIs, User Experience (UX), User Interface (UI), UI Components, Back-end, CI/CD Pipelines, Web Applications, UI Libraries, Component Libraries, Front-end Architecture, Front-end Development, SaaS, CSS3, Multithreading, Algorithms, Linux, Minimum Viable Product (MVP), OAuth, Integration Testing, Postman, Full-stack Development, Customer Relationship Management (CRM), ECMAScript (ES6), SCSS, RDBMS

Senior Full-stack Developer

2019 - 2020

Freelance

Created a React application that generates an HTML page based on data provided in the JSON file, then converted this page into a PDF file using headless Chrome.
Refactored and added new functionality to websites written in AngularJS, including logic and styles.
Developed a data parser that took .txt files as input, then red-lined and decoded them from Base64 to parsed JSON, calculated all needed data, and produced a new file with results.
Communicated with clients from the US, India, and UAE.
Analyzed requirements, provided estimates, and met deadlines.

Technologies: REST APIs, React-Bootstrap, Visual Studio Code (VS Code), Sass, Less, Serverless, Database Design, Databases, Node.js, HTML5, Cross-browser Compatibility, Pixel Perfect, C#, AngularJS, JavaScript, CSS, HTML, React, DevOps, Visual Studio, SQL, Git, GitHub, Full-stack, Windows, Front-end, Web Development, Responsive Web Design (RWD), Bootstrap, Architecture, User Experience (UX), User Interface (UI), UI Components, Back-end, CI/CD Pipelines, Web Applications, Front-end Architecture, Front-end Development, Heroku, Minimum Viable Product (MVP), Full-stack Development, ECMAScript (ES6), SCSS, Prisma, Tailwind CSS, REST

Senior Full-stack Developer

2019 - 2020

e-Boks A/S

Prepared the architecture for a new product that consisted of several services and a SPA. Created user stories, provided estimates, and built the tracking progress.
Conducted about 20 interviews for the project so far.
Created projects from scratch and deepened my knowledge of the security domain.
Refactored and introduced unit testing in products.

Technologies: REST APIs, Visual Studio Code (VS Code), .NET Core, Sass, Less, Database Design, Databases, Test-driven Development (TDD), Node.js, Jira, HTML5, Swagger, Amazon S3 (AWS S3), Amazon CloudFront CDN, MySQL, Angular, OAuth 2, Cross-browser Compatibility, Unit Testing, NUnit, Moq, Pixel Perfect, TeamCity, Octopus Deploy, TFS, LINQ, Entity Framework, Datadog, Microsoft SQL Server, CSS, JavaScript, React, ASP.NET Web API, C#, T-SQL (Transact-SQL), Visual Studio, SQL, Git, Full-stack, C#.NET, .NET, Windows, SQL Server Management Studio, Front-end, Web Development, HTML, Web Performance Optimization (WPO), Responsive Web Design (RWD), API Integration, Architecture, APIs, User Experience (UX), User Interface (UI), UI Components, Back-end, CI/CD Pipelines, Web Applications, Cryptography, Front-end Architecture, Front-end Development, Multithreading, Algorithms, Handlebars, Linux, Amazon Web Services (AWS), Minimum Viable Product (MVP), Integration Testing, Postman, Full-stack Development, Customer Relationship Management (CRM), ECMAScript (ES6), SCSS, REST, RDBMS

Middle Full-stack Developer

2016 - 2019

JustAnswer

Led a subproject, including overseeing the SDD preparation, creating user stories, providing estimates, and tracking progress.
Spearheaded a data quality initiative within the team. The primary goal was to find problems with tracking, introduce solutions and implement them, and ensure correctness via integration and Selenium tests.
Refactored many elements, writing dozens of unit, integration, and Selenium tests.
Conducted extensive A/B testing, including implementing many experiments that required several versions of web pages, which differed in UI and functionality, and compared the conversion rate and other metrics of those pages.
Became deeply familiar with the Scrum methodology here.
Established and ran code reviews for my teammates.

Technologies: REST APIs, Visual Studio Code (VS Code), Sass, Less, Database Design, Databases, Test-driven Development (TDD), Node.js, HTML5, Cross-browser Compatibility, Unit Testing, NUnit, Moq, Pixel Perfect, Git, LINQ, Entity Framework, Redis, Dynatrace, Microsoft SQL Server, React, CSS, ASP.NET MVC, Selenium, JavaScript, C#, T-SQL (Transact-SQL), Visual Studio, SQL, Full-stack, C#.NET, .NET, Windows, SQL Server Management Studio, Front-end, Web Development, HTML, Web Performance Optimization (WPO), Responsive Web Design (RWD), API Integration, Architecture, APIs, User Experience (UX), User Interface (UI), UI Components, Back-end, CI/CD Pipelines, Search Engine Optimization (SEO), Web Applications, Front-end Architecture, Front-end Development, Multithreading, Algorithms, Handlebars, Integration Testing, Postman, Full-stack Development, ECMAScript (ES6), SCSS, Animation, REST, RDBMS

Junior Full-stack Developer

2014 - 2016

ByteAnt

Developed new web pages, including writing styles, JavaScript, database queries, unit tests, and more.
Optimized the performance of SQL queries via stored procedure optimization and database denormalization which reduced the load time from 30 seconds to 100 milliseconds.
Became experienced with ASP.NET MVC, HTML, CSS, JavaScript, jQuery, Angular, Microsoft SQL Server, Elasticsearch, Entity Framework, LINQ, SVN, Git, and TeamCity.

Technologies: Database Design, Databases, PostgreSQL, Elasticsearch, Cross-browser Compatibility, Unit Testing, NUnit, Moq, Pixel Perfect, Git, Subversion (SVN), LINQ, Entity Framework, Microsoft SQL Server, jQuery, JavaScript, CSS, HTML, ASP.NET MVC, C#, AngularJS, T-SQL (Transact-SQL), Visual Studio, SQL, Full-stack, C#.NET, .NET, Windows, SQL Server Management Studio, Front-end, REST APIs, Web Development, Web Performance Optimization (WPO), Responsive Web Design (RWD), API Integration, APIs, User Experience (UX), User Interface (UI), Back-end, Web Applications, Front-end Architecture, Front-end Development, Algorithms, Integration Testing, Postman, Full-stack Development, SCSS, REST, NoSQL, RDBMS

Experience

Fiona Posts

https://digible.com/

A NestJS and React-based application that automates real estate content posting on Google business platform, Facebook and Instagram.

I've developed a minimum viable product (MVP) that automates content posting on Facebook and Instagram, enhancing content delivery efficiency. I also designed multiple content templates for Facebook and Instagram, enriching the MVP's capabilities for diverse posting needs.

Provider Portal

https://www.genedx.com/

The GeneDx Provider Portal provides a fast, efficient, secure, and HIPAA-compliant way for healthcare providers to order tests and access their patients' test result reports.

In a 1.5-year migration project for GeneDx's Provider Portal, I led the transition from AngularJS to React with TypeScript. I designed new Figma-based layouts, created a robust component library, and reverse-engineered legacy code for a seamless migration. The complex ordering flow was reimagined, featuring real-time validation, a dynamic side menu, and data persistence, resulting in an intuitive and efficient user experience. The successful project cemented GeneDx's position as a leader in genetic and genomic testing services.

Atfarm

https://www.at.farm/

A React-based application that helps farmers create crop nutrition plans. The app recommends when, where, and how much fertilizer you should apply. A user can import soil analysis results from many laboratories across different countries. The data can be presented in different formats, e.g., tables, charts, and so on, and can be shared via email as a link or PDF file.
Moreover, it keeps track of the farm's sustainability. It calculates the CO2 and N emissions levels compared to benchmarks and suggests improvements.

ALLEYE CMMS Software

https://www.apsinco.com/alleye-cmms-software

I developed the website, which is used as a CMMS system to manage instrument validation.
It is written in C#, React, and TypeScript and uses SQL server as the database.
I created everything from scratch, which included setting up CI/CD on Azure DevOps with a Git repo and automatic deployments to AWS ECS.
The codebase is covered with unit tests and end-to-end tests using Cypress.io.
Later on, I managed a small team of developers.

JustAnswer

I developed a web service that allows people to get expert's answers in different areas for a small price. It consists of a website (Justanswer.com) where you can ask your own question or find an already-answered one.

e-Boks

https://www.e-boks.com/danmark/da/

I created a web service for the secure transmission and storage of documents introduced to all residents in Denmark. It consists of a website (E-boks.com/danmark/da) and numerous private services. It also has mobile apps for Android and iOS, which provide all primary functionality.

Mechanic Advisor

https://www.mechanicadvisor.com/

I developed a web service that connects people to auto repair shops. It consists of a website (Mechanicadvisor.com) where you can search through a huge list of shops as a customer or manage your business as a shop owner.

HTML to PDF Conversion

I created a React application that generates an HTML page based on data provided in a JSON file. Then this page can be converted to a PDF file using headless Chrome.
The source code can be found here: https://github.com/likerrr777/PrintHtmlToPdf

Skills

Languages

T-SQL (Transact-SQL), CSS, Sass, Less, TypeScript, JavaScript, HTML, SQL, C#, C#.NET, CSS3, ECMAScript (ES6), SCSS, GraphQL, HTML5, Python

Frameworks

Redux, NUnit, ASP.NET, ASP.NET Core, Entity Framework Core, MUI (Material UI), .NET, .NET Core, Jest, Express.js, ASP.NET MVC, NestJS, Cypress, Selenium, JSON Web Tokens (JWT), React-Bootstrap, Swagger, Next.js, Tailwind CSS, ASP.NET Web API, AngularJS, Angular, OAuth 2, Bootstrap

Libraries/APIs

MediatR, AutoMapper, Recharts, REST APIs, React, LINQ, Moq, Entity Framework, Node.js, Handlebars, React-Intl, Formik, Yup, React Router, React Redux, jQuery, Lodash, Urql, Puppeteer, YouTube API, MobX, Stripe

Tools

Visual Studio, Git, GitHub, SQL Management Studio, Figma, Postman, Prisma, JSS, Hangfire, Amazon Elastic Container Service (Amazon ECS), Amazon Elastic Container Registry (Amazon ECR), Sequelize, Jira, Amazon CloudFront CDN, Dynatrace, TFS, TeamCity, AWS IAM, Subversion (SVN), RabbitMQ, CircleCI, Google Analytics, Webpack, Docker Compose

Paradigms

REST, FluentValidation, Code First, Unit Testing, Microservices, Responsive Web Design (RWD), Azure DevOps, Database Design, Test-driven Development (TDD), E2E Testing, Automated Testing, Web Performance Optimization (WPO), DevOps, Search Engine Optimization (SEO), B2C

Platforms

Visual Studio Code (VS Code), Windows, Amazon Web Services (AWS), Linux, Docker, Amazon EC2, AWS Lambda, Twilio, Heroku, Google Cloud Platform (GCP)

Storage

SQL Server 2017, Microsoft SQL Server, RDBMS, SQL Server Management Studio, Databases, PostgreSQL, Amazon S3 (AWS S3), MySQL, Datadog, Redis, Elasticsearch, NoSQL, Google Cloud

Other

Cross-browser Compatibility, Single-page Applications (SPA), React Hooks, Front-end, Authentication, Authorization, APIs, Full-stack, Storybook, SOLID Principles, Multithreading, Design Systems, Styled-components, ESLint, Charts, Web Development, API Integration, Architecture, User Experience (UX), User Interface (UI), UI Components, Back-end, CI/CD Pipelines, Web Applications, UI Libraries, Component Libraries, Front-end Architecture, Front-end Development, Algorithms, Minimum Viable Product (MVP), Integration Testing, Full-stack Development, Customer Relationship Management (CRM), API Gateways, Pixel Perfect, Data Visualization, Axios, Identity, Serverless, React Hook Forms, PDF, MERN Stack, Cryptography, SaaS, OAuth, Integration, Headless Commerce, Animation, Google Analytics 4, Octopus Deploy, Serilog, TypeORM, Team Management, Apollo, Segment, Phrase, Chromium, Cryptocurrency, Applied Mathematics, UIBakery, Web3, Crypto, Decentralized Finance (DeFi), Monorepos, Google Tag Manager, Vercel

Education

2012 - 2018

Master's Degree in Applied Mathematics and Informatics

Ivan Franko National University - Lviv, Ukraine

Certifications

DECEMBER 2020 - PRESENT

NestJS Zero to Hero — Modern TypeScript Back-end Development

Udemy