Web3 & Blockchain Development for Modern Products

We primarily build on Ethereum and EVM-compatible chains (Polygon, Arbitrum, Base, Optimism, BNB Chain). We also work on Solana using Anchor and Rust. Chain selection is driven by your target user base, transaction cost requirements, and ecosystem fit.

We write and thoroughly test smart contracts using Hardhat and Foundry. We conduct an internal security review before recommending an independent third-party audit for any contract holding significant value. We have experience with common vulnerability patterns including reentrancy, front-running, integer overflow, and access control misconfigurations.

Security is built in from the first line of code - not bolted on at the end. We follow the checks-effects-interactions pattern, use OpenZeppelin audited libraries where applicable, write invariant fuzz tests with Foundry, and perform a structured internal review before external audit. We strongly recommend independent audit for any contract holding user funds.

Yes. We have built NFT minting contracts (ERC-721, ERC-1155), royalty enforcement (EIP-2981), allowlist mechanics, and custom marketplace logic with maker/taker order books. We handle IPFS metadata hosting, reveal mechanics, and secondary sale royalty routing.

We have integrated and built on top of Uniswap, Aave, Compound, Chainlink, and Curve. We build custom AMM pools, yield aggregators, lending markets, and vesting contracts. Every DeFi project starts with a formal specification review and economic attack-vector analysis.

We implement sign-in-with-Ethereum (SIWE/EIP-4361) for secure, stateless authentication without passwords. We support MetaMask, WalletConnect, Coinbase Wallet, and Safe (multisig). Session tokens are JWTs bound to the wallet address and expire automatically.

A focused smart contract with a basic dApp frontend takes 6-10 weeks. A full DeFi protocol or NFT marketplace with indexing, analytics, and security review takes 3-6 months. External audit timelines are independent and typically add 2-6 weeks depending on the auditor.

Our estimate model has no Web3 button, so we price the application layer from the platform and the modules it does have: design and development at $35 per hour, QA and testing and project management at $20 per hour each. A token contract with a minting dApp is a web build with wallet accounts, payments and third-party integrations: 630-1,150 hours over 9-16 weeks, or $19,000-$35,000 at our rates. A marketplace with wallet accounts, payments, an admin panel, indexing integrations and live order updates is 860-1,610 hours over 10-18 weeks, or $26,000-$49,000. An independent security audit is a separate line that the audit firm prices, not us, so we do not put a figure of our own on it. Put your own module list together at kultrix.com/cost-calculator.

Yes. We handle cross-chain migrations including contract re-deployment, token bridge integration, and state migration strategies. We also advise on canonical bridge vs. third-party bridge tradeoffs and build the cross-chain messaging logic when bidirectional asset transfer is required.

Yes. We implement OpenZeppelin Governor-based on-chain governance, Snapshot-based off-chain voting with on-chain execution, multi-sig treasury management, and custom voting power mechanisms including delegation and quadratic voting.

Gas optimisation is part of our standard contract development process. We use packing of storage slots, calldata compression, batch operations, and proxy patterns where appropriate. We profile every contract function with Hardhat gas reporter and target specific gas budgets agreed upon during scoping.

We provide a post-launch monitoring setup using tools like Tenderly Alerts or OpenZeppelin Defender Sentinels that notify your team of unusual transaction patterns or contract state anomalies. We also offer retainer-based support for contract upgrades, parameter adjustments via governance, and emergency pause procedures.