FE Tech Solution

[himesh-dev]

PR Summary

Problem 1: Three Ways to Sum to N
The objective of this challenge was to provide three distinct functions that calculate the sum of all integers from one up to a given number n. To solve this, I implemented three fundamentally different programming approaches in JavaScript. The first approach leverages a mathematical formula, offering the most efficient and direct solution. The second uses a standard iterative loop to sequentially add each number, providing a reliable fallback. The final approach relies on recursion, breaking the problem down into smaller, self-calling segments to calculate the total.

Problem 2: Currency Swap Form
This task required the creation of a functional, user-friendly currency exchange form that fetches live token price data. My solution involved migrating the raw requirements into a fully modular React architecture with dedicated UI components. I engineered custom hooks to cleanly manage complex local state and separate the business logic from the presentation layer. To ensure top-tier performance, I integrated memoization techniques that prevent unnecessary component re-renders when interacting with the form. Finally, I improved overall accessibility by implementing full keyboard navigation support for the token selection dropdowns.

Problem 3: Refactoring Inefficient Wallet Code
For this challenge, I was tasked with identifying and fixing several computational inefficiencies, bugs, and anti-patterns within an existing React WalletPage component. I started by correcting flawed useMemo dependencies and broken sorting logic that failed to handle tie-breaker scenarios properly. Next, I eliminated a common React anti-pattern by swapping out array index keys for unique currency identifiers to guarantee stable rendering. To speed up execution, I replaced a heavy switch statement with an O(1) object lookup table and extracted it from the component lifecycle. Ultimately, these targeted refactors transform the widget into a secure, predictable, and highly performant component.