Blockchain Integration with ethers.js and web3.js

Imagine building a website for a DeFi protocol. You connect a wallet via MetaMask, but balances don't load — an SSR hydration error because ethers.js accesses window, or an RPC node fails at the worst moment. From such cases, we've developed a workflow: use ethers.js v6 as the primary tool, web3.js v4 for legacy projects. Below, we break down typical patterns we apply in turnkey blockchain integration development. 5+ years of experience with EVM networks, 20+ integrations for startups and enterprise.

ethers.js v6 is 2-3 times better than web3.js v4 in bundle size and import speed: tree-shaking removes unused modules. Yes, web3.js v4 is rewritten in TypeScript, but ethers.js offers a cleaner API, native BigInt, and built-in ESM support. For a new project — definitely ethers.

How to choose between ethers.js and web3.js?

For new projects, we definitely recommend ethers.js v6: it's lighter, faster, has better typing. web3.js v4 remains relevant for migrating from older versions.

What does the integration work include?

We provide a full set:

• Requirements analysis and library selection.
• Designing the contract interaction layer (ABI, addresses, networks).
• Implementing data read/write, event subscription, error handling.
• Developing fallback providers for fault tolerance.
• Testing integration on test networks (Goerli, Sepolia).
• Documentation and access handover.

After completion, we guarantee stable operation — if issues arise within a month, we fix them free of charge.

How to ensure RPC fault tolerance?

Note: when one RPC node goes down, the application should instantly switch to another. We use FallbackProvider from ethers.js with weight and priority distribution. Configuration example:

import { FallbackProvider, JsonRpcProvider } from 'ethers';

const fallbackProvider = new FallbackProvider([
  { provider: new JsonRpcProvider('https://rpc1.example.com'), priority: 1, weight: 2 },
  { provider: new JsonRpcProvider('https://rpc2.example.com'), priority: 2, weight: 1 },
]);

We also handle errors via try-catch and log failures for monitoring.

Why is ethers.js v6 faster than web3.js v4?

Due to aggressive tree-shaking: ethers.js exports modules as separate ESM files, so the bundler removes unused parts. In web3.js v4, despite TypeScript, many functions are tied into a single module, increasing size.

ethers.js v6: key concepts

import {
  BrowserProvider,
  JsonRpcProvider,
  FallbackProvider,
  Contract,
  formatEther,
  parseEther,
  formatUnits,
  parseUnits,
  isAddress,
  getAddress,
} from 'ethers';

// Server provider
const serverProvider = new JsonRpcProvider(process.env.ETH_RPC_URL);

// Client provider
async function getWalletProvider() {
  if (!window.ethereum) throw new Error('Wallet not found');
  const provider = new BrowserProvider(window.ethereum);
  const signer = await provider.getSigner();
  return { provider, signer };
}

// Fallback provider (multiple RPC)
const fallbackProvider = new FallbackProvider([
  { provider: new JsonRpcProvider('https://rpc1.example.com'), priority: 1, weight: 2 },
  { provider: new JsonRpcProvider('https://rpc2.example.com'), priority: 2, weight: 1 },
]);

Working with contracts and events

const ERC20_ABI = [
  'function balanceOf(address owner) view returns (uint256)',
  'function transfer(address to, uint256 amount) returns (bool)',
  'function approve(address spender, uint256 amount) returns (bool)',
  'function allowance(address owner, address spender) view returns (uint256)',
  'event Transfer(address indexed from, address indexed to, uint256 value)',
];

// Read-only
const tokenRead = new Contract(TOKEN_ADDRESS, ERC20_ABI, serverProvider);
const balance = await tokenRead.balanceOf(walletAddress);

// Write with signature
const { signer } = await getWalletProvider();
const tokenWrite = new Contract(TOKEN_ADDRESS, ERC20_ABI, signer);
const tx = await tokenWrite.transfer(recipientAddress, parseUnits('10', 18));
const receipt = await tx.wait();

// Event subscription
const filter = tokenRead.filters.Transfer(null, walletAddress);
tokenRead.on(filter, (from, to, value) => {
  console.log(`Received ${formatUnits(value, 18)} from ${from}`);
});

// Historical events
const events = await tokenRead.queryFilter(filter, fromBlock, 'latest');

web3.js v4

import { Web3 } from 'web3';

const web3 = new Web3(window.ethereum);
const erc20Contract = new web3.eth.Contract(ERC20_ABI, TOKEN_ADDRESS);

// Read
const balance = await erc20Contract.methods.balanceOf(walletAddress).call();

// Write
const accounts = await web3.eth.getAccounts();
const receipt = await erc20Contract.methods
  .transfer(recipient, web3.utils.toWei('10', 'ether'))
  .send({ from: accounts[0] });

BigInt and utilities

// BigInt serialization (JSON.stringify doesn't support it)
const replacer = (_: string, value: unknown) =>
  typeof value === 'bigint' ? value.toString() : value;

// Address shortening
function shortenAddress(address: string): string {
  return `${address.slice(0, 6)}…${address.slice(-4)}`;
}

// Block timestamp conversion
async function blockToDate(blockNumber: number): Promise<Date> {
  const block = await serverProvider.getBlock(blockNumber);
  return new Date(Number(block!.timestamp) * 1000);
}

Integration timelines: basic (read + one event) — 1-2 days, full layer with multiple contracts, fallback, and history — 3-4 days. Cost is determined after analysis based on complexity. For an accurate estimate, contact us — we'll discuss your project and suggest the optimal solution.

When to order blockchain integration development?

If you are building a Web3 application — DeFi protocol, NFT marketplace, or corporate blockchain solution — it's important to properly organize the network interaction layer from the start. Errors in ABI, incorrect BigInt handling, lack of fallback providers lead to production failures and user dissatisfaction.

We take over the entire development cycle: from library selection and provider setup to implementing event subscriptions and testing on test networks (Sepolia, Mumbai). We work with EVM-compatible networks: Ethereum, Polygon, BNB Chain, Arbitrum, Optimism. Clients receive clean TypeScript code, documentation, and one month of technical support. Reach out to us — we'll evaluate your project and find the optimal solution within 1 business day.

Source: ethers.js v6 Documentation

Frontend Development with React: From Audit to Production

Bundle grew to 3.1 MB gzip — that's a real figure from a project that came to us for an audit. The cause: moment.js (72 KB) pulled locales for all 160 languages, lodash was imported in full instead of tree-shaken, and three component libraries were connected simultaneously. TTFB was excellent, but TTI on mobile was 14 seconds. Users left, conversion dropped by 40%. We rewrote the frontend: removed duplicate libraries, implemented dynamic imports, and SSR. Result: bundle reduced to 850 KB gzip, TTI to 2.1 seconds, LCP to 1.8 s.

Frontend is not about "drawing prettily". It's about performance, typing, rendering strategy, bundle management, and maintainability for years.

Why is Next.js the Standard Choice for SEO?

React is our primary UI framework for complex interfaces. Next.js is the standard choice for projects with SEO requirements or SSR. App Router brought React Server Components, streaming, and fetch with built-in caching. Real benefits: a catalog page with thousands of products renders on the server without sending filtering logic to the client, JS bundle is 30% smaller.

But App Router is a different way of thinking. "use client" must be placed consciously. A real mistake: a developer marks the entire layout as "use client" because of a single navigation state — and loses all RSC advantages. Rule: keep Server Components as high as possible in the tree, "use client" only for interactive leaf components. ISR for a catalog with 50,000 pages using ISR and CDN delivers TTFB < 50 ms for any page.

How Does TypeScript Prevent Bugs in Production?

TypeScript is mandatory on any project planned to be maintained longer than 3 months or with more than one developer. The argument "we write fast without types" works only for the first 2 weeks. After that, bugs related to undefined values appear every week.

Specific benefit: refactoring an API response — change a type in one place, TypeScript shows all places needing adaptation. Without types, a production bug appears in a week. strict: true in tsconfig.json is mandatory. noImplicitAny, strictNullChecks, strictFunctionTypes. The pain of Type 'undefined' is not assignable in development is less than Cannot read properties of undefined in production. tRPC provides end-to-end typing from backend to frontend without separate schema — changing a procedure type immediately shows places on the frontend that need fixing.

Vue 3 + Nuxt 3 — An Alternative SSR Stack

Vue 3 with Composition API offers a different development style, closer to React Hooks. <script setup> and composables make code more reusable. Nuxt 3 is a framework for Vue with SSR/SSG, similar to Next.js. useAsyncData and useFetch are built-in composables with request deduplication and hydration. Auto-imports are convenient but can confuse during debugging. Nuxt Content is a module for Markdown/MDX files, ideal for documentation.

Hydration mismatch is a specific pain of SSR in Vue and React. Solution: <ClientOnly> component for browser-only content, suppressHydrationWarning for dynamic timestamps.

Performance: Metrics and Tools

Bundle analysis is the starting point. @next/bundle-analyzer or rollup-plugin-visualizer — run before every major deployment. Goal: no page should require > 200 KB JS gzip for first paint.

Dynamic imports for heavy components:

const RichEditor = dynamic(() => import('@/components/RichEditor'), {
  ssr: false,
  loading: () => <EditorSkeleton />,
});

Editor (Tiptap, Quill, CodeMirror) are typical candidates for dynamic import. Without this, they end up in the main bundle. React DevTools Profiler for finding unnecessary re-renders. React.memo, useMemo, useCallback are targeted tools. Premature memoization of everything adds overhead without benefit. Profile first, optimize later.

Virtualization of long lists: @tanstack/virtual or react-window render only visible items. Table with 50,000 rows: with virtualization — 60fps, without — browser freezes on scroll.

State Management: Without Overengineering

For most applications, it's enough to have:

• React Query / TanStack Query — for server state (API data, caching, invalidation)
• Zustand — for global client state (lightweight, no Redux boilerplate)
• React Hook Form — for forms

Redux Toolkit is justified for very complex global state with many interactions. For most tasks, it's overkill. Recoil, Jotai — atomic approaches for independent pieces of state.

How to Choose the Right CSS and Design System?

Tailwind CSS latest version is our standard choice for new projects. Utility-first, excellent integration with component libraries (Radix UI, Headless UI), PostCSS pipeline. CSS Modules are an alternative when more explicit style isolation is needed. Radix UI + Tailwind (Shadcn/ui pattern) offers headless components with full control over styles. No dependency lock-in: components are copied into the project and fully customizable. Storybook is used for documenting the component library.

React DevTools Profiler — the official tool from the React team.

Testing

E2E tests via Playwright — for checkout, authentication, critical forms. Not for everything: maintaining a large e2e suite is expensive, so we select 3-5 key scenarios.

What's Included in the Scope (Deliverables)

Every frontend project we deliver includes:

• Source code in Git with full commit history and branching strategy
• Architecture document — component tree, data flow, routing decisions
• Component documentation – Storybook with stories for all reusable components
• CI/CD pipeline – automated builds, linting, tests, deployment config (Vercel / Netlify / custom)
• Access to staging environment during development and after launch
• Team training – 2‑3 live walkthrough sessions with your developers
• 3‑month warranty on any bugs found in production
• Performance report – LCP, TTI, TTFB, bundle size before/after

We also provide a pre‑deployment checklist covering browser testing, security headers, cookie compliance, and accessibility audit.

Estimates and Scope

Cost is calculated after decomposition into components, screens, and API integration. We use N+1 estimation: add 20% for risks.

What Does a Typical Performance Audit Reveal?

A recent e‑commerce project had LCP of 4.2 seconds and a monthly cloud bill of $3,000. After moving to edge‑caching (ISR + CDN) and eliminating render‑blocking scripts, LCP dropped to 1.1 seconds, and the bill fell to $1,800. The client recovered an estimated $12,000 per year in lost revenue from improved conversion. That's the kind of before‑after we regularly deliver.

Comparing tools: Next.js is 20‑30% faster in SSR builds than Nuxt with the same page size. TypeScript reduces production bugs by 60‑70% compared to JavaScript. A well‑structured bundle with code‑splitting cuts first‑paint JS by more than half.

We have 5 years of frontend development experience, over 50 completed projects, a team of 10 engineers proficient in React, Vue, Angular. We work with technologies described in React documentation and TypeScript. Additional information can be found in Wikipedia: React and Wikipedia: TypeScript.

What Stack to Choose for Frontend Development with React?

We compare tools by real metrics. Next.js is 20‑30% faster in SSR builds than Nuxt with the same page size. TypeScript reduces production bugs by 60‑70% compared to JavaScript. Savings on maintaining such a project can be significant due to reduced debugging time. If you need a lightweight SPA with minimal cost, React + Vite is enough. For a content site with SEO, Next.js with ISR gives TTFB below 50 ms even with 50,000 pages.

Get a consultation for your project: we'll evaluate your current code and propose an optimization plan. Order an audit — we'll find bottlenecks and show how to reduce budget without losing quality. Contact us to start the discussion.