Anton

ANTON TYMOSHENKO
Frontend Engineer
React / TypeScript / SaaS and AI applications
Lviv, Ukraine | Remote | [відкрити контакти](див. вище в блоці «контактна інформація»)
[відкрити контакти](див. вище в блоці «контактна інформація») | github.com/Leonardo1912

Frontend Engineer with 4 years of commercial experience building and evolving React and TypeScript
applications for SaaS and AI products. Own frontend technical decisions, translate business requirements
into implementation plans, and improve application responsiveness and reliability. Combine hands-on
development with developer onboarding, task coordination, and code reviews.
Technical skills
Frontend: React, TypeScript, JavaScript, Next.js, HTML, CSS/SCSS, Tailwind CSS
State and APIs: Redux Toolkit, RTK Query, REST APIs, SSE, SignalR, Pusher
Delivery and quality: Git, Vercel, Sentry, ESLint, Jest (backend tests)
Backend: Node.js, PostgreSQL, Redis, BullMQ

Professional experience

ProCharted
Project contributions since Nov 2022 | Currently part-time
Frontend Developer | Initially via Luna Edge; now directly with the client
Accounting practice management SaaS spanning work management, billing, and automation.
React, TypeScript, Redux Toolkit, RTK Query, Tailwind CSS, SignalR, Recharts
Owned frontend technical decisions as the sole frontend developer; translated PM requirements into
implementation tasks and coordinated API and data needs with the backend developer.
Developed client management, billing, time tracking, and workflow automation, including recurring work,
email integration, and QuickBooks Online customer matching.
Modernized core frontend modules, adapting business logic and user flows to evolving requirements and
redesigns while reorganizing module boundaries and API integrations.
Identified loading delays and proposed UX improvements, decoupling independent data requests and
reducing unnecessary refetches to keep the interface responsive.
Improved data consistency across user workflows through RTK Query cache updates and invalidation,
eliminating the need to reload pages to see changes.
Stabilized time tracking by reconciling SignalR events with client state, preventing timer rollback during
navigation.

Luna Edge Nov 2022 - Jun 2026
Frontend / Full-Stack Developer | Remote
Delivered client projects across SaaS, AI, and Telegram applications.

OnDemand
AI platform with a developer playground, usage analytics, and an administration console.
React, TypeScript, Redux Toolkit, Tailwind CSS, Chart.js, Server-Sent Events
Established the frontend foundation: page organization, routing, lazy loading, and shared layouts.
Onboarded and coordinated three frontend developers through task allocation, troubleshooting, and PR
reviews, helping them progress to independent delivery.
Took on urgent and complex features and guided AI chat redesigns, clarifying business logic and
identifying missing user flows during implementation and review.
Developed AI execution feedback via SSE, usage analytics, and administrative tools for managing
companies, users, API limits, and service configuration.

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ANTON TYMOSHENKO | Frontend Engineer
Selected client projects continued
Luna Edge | Nov 2022 - Jun 2026

SchoolHack
AI learning application with document-based quizzes, messaging, and a knowledge library.
React, TypeScript, Redux Toolkit, Pusher, REST APIs, SCSS
Delivered frontend assessment workflows from document or audio selection through timed attempts,
answer submission, results, and attempt history.
Implemented paginated messaging with Pusher-driven message and notification updates, integrating
asynchronous events into conversation state.
Refined document-upload and processing flows, keeping list refreshes aligned with upload state and
adapting learning and messaging interfaces for mobile.

Telegram Mini App and Rewards Platform
Telegram application with task rewards, purchases, withdrawals, and administration tools.
React, TypeScript, RTK Query, Tailwind CSS, Node.js, PostgreSQL
Co-designed the backend structure and established the initial frontend foundation and typed API layer,
then focused on backend business logic.
Implemented balance and withdrawal workflows with PostgreSQL transactions, decimal arithmetic, and
idempotency keys; aligned cached purchase state with completed operations.
Added and maintained Jest tests for reward processing and balance operations, covering repeated
requests, insufficient funds, transaction rollback, and concurrent debits.

Additional project experience
ProCharted website. Built contact and new-firm registration interfaces with Next.js, TypeScript, Formik,
and Tailwind CSS.
Vision Cinex. Developed authentication, profile, settings, and chat features for web and mobile film-
production applications using React and React Native.
Partner relationship management platform. Built onboarding, user-management interfaces, and charts
with React, TypeScript, and Material UI.

Delivery and reliability
Managed Git-based frontend delivery on Vercel for OnDemand and ZeeStore, including automatic builds,
environment configuration, previews, and build troubleshooting. Diagnosed issues reported by users, QA,
and Sentry; strengthened error handling for failed or incomplete backend responses and manually verified
affected workflows.

Education
Lviv Polytechnic National University | Bachelor's degree in Cybersecurity | 2019 - 2023

Languages
English: Upper-Intermediate | Ukrainian: Native

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