Oleksii

Oleksii Chalyi
Summary
• 10+ years of professional experience in the IT industry, programming, object-oriented design, data
modeling, web applications development.
• Extensive experience working with a diverse full-stack ecosystem, including React, Redux, Next.js,
Angular, Node.js, NestJS, MongoDB, PostgreSQL, Microservices.
• Has UI/UX experience, critical and creative thinking, attention to detail, sense of personal
responsibility and self-management.
• Dedicated to activities that help to stay sharp and creative, e.g. drawing, playing soccer, learning
psychology, riding a bicycle or just discovering something new and interesting.

Contacts
Linkedin:[open contact info](look above in the "contact info" section)
Email: [open contact info](look above in the "contact info" section)
GitHub: http://github.com/alex-chaliy
Stackoverflow: https://stackoverflow.com/users/7455192/meteor?tab=answers

Skills
Programming Languages and Core Concepts:
Javascript • Typescript • OOP • TDD • T-Shaped approach •
Design Patterns • Monorepo •
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Frontend Technologies:
Angular • Angular Material • RxJS / NgRx • HTML • Micro-frontend •
CSS / SCSS • Tailwind CSS • React • Redux • Redux.js •
GSAP • Zustand • Formik • SWR • React Query • Next.js •
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Version Control System and CI/CD:
Git • GitFlow • CI/CD • Github Actions • Bitbucket Pipelines •
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Backend Technologies:
Node.js • NestJS • Express.js • MongoDB • PostgreSQL • Swagger •
Microservices • RabbitMQ • Apache Kafka • RedPanda •
REST API • GraphQL • WebSockets • Socket.io •
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Testing Libraries:
Jest • Karma.js • Jasmine.js • React Testing Library •
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Cloud Services and Tools:
AWS • Microsoft Azure • Docker •
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AI Tools and APIs:
OpenAI • LLM • Anthropic API • Claude Code • Github Copilot •
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Build Tools and Compilers:
WebPack • Turbopack • Vite • SWC • Babel •

Tools
Figma, Claude, Gemini, shadcn/ui, Lighthouse, React DevTools, Redux DevTools,
Browser DevTools, Postman, TSLint, Prettier, Linux, MacOS.
IDE
Visual Studio Code, WebStorm

Domains
Advertising / Marketing, E-commerce / Marketplace, Education, Fintech, Healthcare / MedTech,
Manufacturing, HRTech, SaaS, Dating

Professionalexperience
[2023 Dec - 2026 Jan] NDA, Brussels, Belgium (remote)
Position: Senior Full-Stack Developer (Angular, NestJS) dating
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• Created and supported web and mobile dating applications serving 1M+ users across Europe.
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• Managed and mentored a team of 3 junior developers, guiding their growth and ensuring delivery of
high-quality product features.
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• Collaborated with a full-stack tech lead to design and plan the entire application architecture,
including the admin panel, the main website, and the mobile applications.
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• Built complex admin panel featuring interactive charts, diagnostics, and user management tools,
enabling analysis of audience demographics(e.g. region, age, hobbies) and efficient resolution of user
requests and reports.
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• Owned full-stack development for core application features: designed and implemented reusable UI
elements (including buttons, form inputs, custom select, header, footer), complex multi-parameter
search filters, and gesture-based swipe mechanics paired with robust back-end logic.
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Backend Stack: Node.js, NestJS, GraphQL, Typescript, PostgreSQL, Jest, TypeORM, ClassValidator,
Microservices, Docker, AWS (Lambda, S3 etc.) RabbitMQ, Anthropic API, OpenAI.
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Frontend Stack: Angular 20, Typescript, ES6+, RxJS, NgRx, SCSS, HTML, Apollo Angular (to work with
API based on GraphQL), Karma, Jasmine, Ionic for Angular, CapacitorJS, HighCharts, GSAP.
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Additional Tools: Git, GitFlow, Jira, Agile, VS Code, Redux DevTools,
Prettier, TSLint, CI/CD, GitHub Actions, Lighthouse, Claude, Github Copilot.
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Team: me as a full-stack developer, 2 frontend developers, 1 ui/ux designer, 1 project manager, 1
full-stack tech lead, 1 backend developer, 2 QA engineers.

[2022 Oct - 2023 Nov] Phobosys, Odesa, Ukraine
Position: Senior React Developer saas
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• Engineered new features and fixed bugs across 5+ applications for a major web-hosting provider.
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• Led development on Notifications Constructor application with complex business logic within a suite
of multiple web applications.
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• Managed and mentored 3 junior front-end developers, fostering growth and improving product quality
across company applications.
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• In the Notifications Constructor implemented a complex flow from users list with search, sorting,
virtual scroll and pagination features, to constructing notification for a specific user in few steps with
multiple form inputs and specific form validations, custom selects, checkboxes/radio-buttons based
on complex business logic where some fields were dependent on values from previous fields and
other parameters depended from the business logic.
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• Designed a redux store to manage data-flows and application state.
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• Developed promotion landing pages with GSAP (animation library).
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• Took a part in other company products for bug fixing and creating new features, e.g. in the Servers
Managing Dashboard application.
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• Specifically, debugged and fixed critical bugs in the service purchasing flow, which helped increase
company revenue by 10%.
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Stack: React.js, Redux.js, Zustand, ES6+, Next.js, GraphQL, React-Query, Fetch API,
Jest, React Testing Library, Formik, Yup, SCSS, Tailwind CSS, HTML, GSAP (GreenSock Animation
Platform), Microservices, Micro-frontend Architecture, Microsoft Azure.
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Additional Tools: Git, GitFlow, Jira, Agile, VS Code, Lighthouse, React DevTools, Redux DevTools,
Prettier, JSLint, CI/CD, Bitbucket Pipelines, Swagger.
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Team: 7 frontend developers, 1 ui/ux designer, 1 scrum manager, 2 full-stack tech leads, 3 backend
developers, 2 QA engineers.

[2020 Sep - 2022 Oct] 1Touch.io, Kyiv, Ukraine (remote)
Position: Senior Full-Stack Developer (Angular, NestJS) saas
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• Developed and supported applications for GDPR system with AI-based document processing across
multiple software products.
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• Took ownership for the Installation Tool web application whose purpose was to help clients to install
1Touch.io products on their local servers automatically without calling installation managers. I built
and developed it from scratch closely communicating with the ui/ux designer, product owner, tech
lead and QA team.
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• As a result, decreased the cost of installing and supporting company products by 90%.
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• Resolved 50+ bugs and developed new features contributing to multiple company products.
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• Notably, optimized the Document Processing application by implementing lazy-loading and virtual
scroll for large document lists exceeding 1k+ items, removing UI lags.
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• Increased search speed by 2x by optimizing complex SQL queries.
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• Took the lead in managing a junior front-end developer to help him grow and bring high quality values
to the company products.
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Frontend Stack: Angular 10, Angular Material, Typescript, ES6+, RxJS, NgRx,
SCSS, HTML, Storybook, Karma, Jasmine, HighCharts, Socket.io.
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Backend Stack: Node.js, NestJS, Typescript, REST API, PostgreSQL,
Jest, ClassValidator, WebSockets, Socket.io, Microsoft Azure (Azure Blob Storage, Azure Functions
etc), Apache Kafka (RedPanda), RabbitMQ, Microservices
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Additional Tools: Git, GitFlow, Jira, Agile, VS Code, Lighthouse, Redux DevTools, TSLint, Prettier,
Swagger.
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Team: a worldwide team mostly based in Ukraine but also in Israel and USA. Me as full-stack
developer, junior frontend developer, 5 QA engineers, 3 backend engineers, 2 full-stack tech leads, 1
designer, 3 product owners, 3 AI engineers.

[2019 June - June 2020] Asseco, Warsaw, Poland (remote)
Position: Angular Developer saas, hr tech
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• Designed custom staff and client management system with dashboard featuring 15+ complex UI
charts, collaborating with backend developers and UI/UX designer.
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• Engineered real-time interactive charts to deliver live audience analytics and system diagnostics
using Highcharts and Socket.io, processing data from 5+ sources.
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Stack: Angular 8, Angular Material, REST API, NgRx, RxJS, SCSS, HTML, Typescript, ES6+, Karma,
Jasmine, WebSockets, Socket.io, AWS, HighCharts, GSAP (GreenSock Animation Platform)
Additional Tools: Git, GitFlow, Jira, Agile, Redux DevTools, Lighthouse, VS Code, TSLint, Prettier.

[2018 Oct - 2019 June] Dataart, Odesa, Ukraine
Position: React Developer healthcare / med tech
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Supported and developed new features, fixed bugs on healthcare applications for managing schedules
and medical data for 100+ clinics.
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Stack: React, REST API, Next.js, MobX, Jest, React Testing Library, Formik, Yup, Typescript, SCSS,
Tailwind CSS, HTML.
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Additional Tools: Git, GitFlow, Jira, Agile, VS Code, TSLint, Prettier.
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Team: 4 frontend developers, 1 designer, 1 project manager, 2 backend developers, 1 QA engineer.

[2017 Oct - 2018 Oct] WorkNest LTD, Elifelet, Israel (remote)
Position: React Developer saas, e-commerce, manufacturing, advertising, healthcare
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• Engineered a healthcare application designed to manage doctor and patient data for a clinic.
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• Additionally, developed new features and fixed bugs across various outsourced projects in the saas,
e-commerce, manufacturing and advertising domains.
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Stack: React, Next.js, REST API, Redux.js, Jest, Typescript, SCSS, HTML.
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Additional Tools: Git, GitFlow, Jira, Agile, Kanban, VS Code, TSLint, Prettier.
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Team: 5 frontend developers, 1 designer, 1 project manager, 3 backend developers, 2 QA engineers.

[2017 Aug - Oct] Freelanceprojects –CasinoWin,CasinoGames
Position: Full-stack Developer, UI/UX Designer
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Frontend Stack: Angular 4, Angular Material, HTML, SCSS, RxJS, Typescript, Karma, Jasmine
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Backend Stack: Node.js, Express.js, REST API, PostgreSQL, ES6+
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Additional Tools: Git, GitFlow, Trello, Agile, VS Code, TSLint, Prettier.

[2017 Jan - Aug]482.Solutions, Odesa, Ukraine
Position: React Developer
Position: Full-Stack Developer saas, hr tech
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Developed web application helping maritime workers find jobs and shipping companies recruit crew
with required skills, serving 100k+ users.
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Stack: React, Next.js, REST API, Redux.js, Typescript, HTML, SCSS, Bootstrap CSS.
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Additional Tools: Git, GitFlow, Jira, Agile, VS Code, TSLint, Prettier.

[2016 Apr - Oct] DoITProgrammingSolutions, Odessa, Ukraine
Position: Full-Stack JavascriptDeveloper e-commerce, advertising, healthcare, education
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Engineered features and resolved bugs across client-facing e-commerce, advertising, healthcare and
education platforms.
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Stack: Node.js, Express.js, React, Redux.js, Angular.js, Angular 2+, REST API, HTML, CSS/SCSS,
Bootstrap CSS, ES6+, MongoDB, PostgreSQL, WebSockets, Socket.io.
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Additional Tools: Git, GitFlow, Jira, Trello, Redux DevTools, Agile, Kanban, VS Code, JSLint, Prettier.

[2015]Self-Employed - Freelance
Position: Full-Stack Developer saas, e-commerce, education, advertising
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Designed and maintained custom features while resolving complex technical issues across a variety
of freelance projects in the saas, e-commerce, education and advertising sectors.
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Stack: React.js, Angular.js, REST API, Javascript,PHP, MySQL, HTML, CSS, Bootstrap CSS
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Additional Tools: Git, Trello, WebStorm.

[2014 May-Nov]Ossystem, Chornomorsk, Ukraine
Position: Intern Web-Developer
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Javascript,PHP, MySQL, HTML, CSS

Education
Odesa National Polytechnic University, Computer Science,
finished 3 classes (2014 - 2017)

Foreign Languages
English B2 (Upper-Intermediate)

Projects
1) Feel the Flow - React/Next.js:
https://github.com/alex-chaliy/responsive-react-app
Demo (any device): https://responsive-react-app.appwrite.network/
Stack: React, Next.js, Zustand, Formik, Yup,
GSAP (GreenSock Animation Platform), SWR, SCSS, HTML.

2) Wakanda - Angular: https://github.com/alex-chaliy/wakanda-forever
Description: Parallax Effect
Demo (desktop only): https://personal-projects-wakanda.appwrite.network/main

3) Task API - NestJS / GraphQL:
https://github.com/alex-chaliy/task-api

4) Services Landing - React/Next.js
https://github.com/alex-chaliy/services-landing
Demo (any device): https://services-landing.appwrite.network/