We are looking for an experienced frontend developer to continue working on Coinfolio — a Telegram Mini App for tracking a crypto portfolio with real-time data, managing multiple portfolios, and smart price notifications.
About the project
Coinfolio is a production-ready application in Telegram (@coinsfolio_bot). Users track their crypto assets directly within Telegram: current prices, P&L calculation, and push notifications for price alerts.
Stack: Next.js 15 (App Router), TypeScript, Tailwind CSS v4, Radix UI, Telegram UI, Zustand, React Query (TanStack), Framer Motion, i18next, Recharts. Backend: Node.js on Railway + PostgreSQL. The frontend is deployed on Vercel.
How we work
We start with a small paid test task — fixing a real bug in production. If everything goes well, we move on to a long-term collaboration: new features, UI improvements, performance optimization, and UX. The codebase is clean, well-structured, and follows modern React patterns.
Test task — bug in the modal on iPhone
In the modal window that opens when adding a crypto asset to the portfolio, there is a UI bug. It manifests specifically on iPhone (iOS Safari / embedded Telegram browser) and causes layout or interaction issues within the modal. Your task is to reproduce, debug, and fix it.
A physical iPhone is not required — you can use Telegram Web (web.telegram.org) and browser DevTools with a mobile viewport to reproduce and debug.
If the fix is of high quality and communication is smooth — we continue working together.
Requirements: confident experience with Next.js, TypeScript, and Tailwind CSS; familiarity with Telegram Mini Apps or similar mobile environments with constraints; experience debugging iOS-specific layout, scrolling, and focus issues; a sense of UI/UX. React Query and Zustand are a plus.
Before you apply
Applications that do not follow these steps will not be considered.
Please open @coinsfolio_bot in Telegram and go through the flow of adding a crypto asset to the portfolio — open the modal, interact with it. In your application, indicate: did you notice the bug and what exactly did you see; what is your initial hypothesis about the cause — a final solution is not needed, just a direction of thought: keyboard behavior on iOS, scroll containment, focus issues, viewport peculiarities in Telegram, etc. We have already tried several approaches, so it is important to understand which direction you are thinking in.
We are waiting for those who love to delve into details.