Blog — page 11
Technical writing on Web3, AI, Bitcoin, and building software. Written by Uvin Vindula.
150 articles
The Complete Guide to OpenZeppelin Contracts
OpenZeppelin Contracts is the library I install before writing a single line of Solidity. This guide covers every contract family I use in production: ERC-20, ERC-721, ERC-1155 token standards, AccessControl for role-based permissions, ReentrancyGuard for security, Governor for on-chain governance, and the UUPS proxy pattern for upgradeability. You will learn how to extend OpenZeppelin contracts properly, when to override versus compose, and the exact patterns I follow across mainnet deployments on Ethereum, Arbitrum, and Base. Practical Solidity code, no theory padding.
Building an AI Chatbot That Actually Works
Most AI chatbots are glorified search bars that hallucinate. Here's how to build one that actually works — with proper context management, streaming responses, conversation memory, and guardrails that prevent your chatbot from confidently lying to customers. Based on real production experience building the EuroParts Lanka AI Part Finder with Claude API, Next.js, and TypeScript. Includes complete code examples, architecture decisions, and a production checklist.
Bitcoin Halving Explained: What It Means and What Happens Next
The Bitcoin halving is one of the most important events in cryptocurrency — yet most people do not actually understand what it is or why it matters. Every 210,000 blocks, the reward that miners receive for validating transactions is cut in half. This is not a decision made by a committee. It is code. It was written into Bitcoin's protocol by Satoshi Nakamoto in 2008 and it will continue executing until roughly the year 2140. In this article, I break down the halving mechanism in plain English, walk through every historical halving with real price data, explain the supply economics that make Bitcoin fundamentally different from fiat currency, and share my perspective as someone who has been educating people about Bitcoin across Sri Lanka and the UK since 2020.
Web3 Authentication: Wallet-Based Login for Modern Apps
A practical guide to implementing wallet-based authentication using wagmi, RainbowKit, and Sign-In with Ethereum (SIWE). Covers session management, backend verification, multi-chain support, and the UX patterns that actually get users through the login flow without confusion.
TypeScript Patterns I Use in Every Production App
The TypeScript patterns that survive production: strict mode enforcement, Zod runtime validation, discriminated unions for state machines, branded types for entity IDs, generic API clients, type-safe environment variables, and the utility types that actually matter. Real code from apps I've shipped, not textbook examples. Includes patterns I stopped using and why.
Understanding Ethereum Virtual Machine: A Developer's Guide
A developer's deep dive into the Ethereum Virtual Machine — how bytecode executes, stack-based computation works, gas metering prices every operation, and storage layout affects your contract costs. Written from hands-on Solidity experience, not textbook theory.
Prompt Engineering for Production Applications
A practical guide to prompt engineering for production applications, drawn from shipping real AI features with the Claude API. Covers system prompt design, few-shot vs zero-shot patterns, chain-of-thought reasoning, structured JSON output, temperature tuning, and systematic testing. Includes real prompt examples from the EuroParts Lanka AI Part Finder, where natural language descriptions get mapped to exact OEM part numbers for 40,000+ European car parts.
How to Build an NFT Marketplace from Scratch
A full-stack guide to building an NFT marketplace — from a Solidity marketplace contract with listing, buying, and bidding logic to royalty enforcement with ERC-2981, a React frontend with wagmi, and IPFS metadata storage. Security-first approach based on real client builds.
How I Built the EuroParts Lanka AI Part Finder with Claude
A build log of how I integrated Claude's API into europartslanka.lk to let customers describe car problems in plain English and get back exact OEM part numbers, compatible models, and pricing — serving 966 customers and 1,444 parts delivered.
Deploying Smart Contracts on Arbitrum: Step-by-Step
A practical step-by-step guide to deploying Solidity smart contracts on Arbitrum using Foundry. Covers testnet and mainnet deployment, contract verification, gas cost comparison with Ethereum, and key differences you need to know before going live.
Claude API vs OpenAI API: An Honest Comparison for Developers
A developer-first comparison of Claude API and OpenAI API covering pricing, response quality, tool use, streaming, and developer experience — based on months of production usage building real products.
Building a DAO Governance System with Solidity and React
A complete guide to building a production DAO governance system — from OpenZeppelin Governor contracts and timelock execution to a React frontend with wagmi. Based on real governance contracts I have deployed for clients.