Blockchain & Web3 Development Company

SemBricks is a Dutch software development company that builds blockchain and web3 applications. We write the smart contracts, and just as importantly the software around them: the dapp frontend, the wallet connection, the backend that indexes on-chain data and the tools your team uses to run the product.

We work on Ethereum and other EVM chains, including layer 2 networks such as Base and Arbitrum, and on Solana. Our focus is on applications where correctness matters: tokens, trading, payments and DeFi, where a mistake costs real money.

Blockchain Development Services

• Smart contract development in Solidity and Rust, with tests, security review and audit support.
• DeFi development: vaults, staking, reward systems, yield dashboards and position management.
• Crypto wallet development: browser extension, mobile and desktop wallets, and hardware wallet signing.
• Account abstraction and paymasters: smart accounts and gasless transactions for a smoother user experience.
• On-chain trading tools: DEX integrations, bots, portfolio trackers and execution tooling.
• Blockchain data indexing: turning on-chain events into fast, queryable data for your application.
• Multi-chain tooling: applications that work across several chains, including bridges.
• On-chain automation: scheduled and event-driven transactions that run reliably without manual work.
• Crypto tax software: reconstructing transaction histories and calculating positions for reporting.

Want users to transact without holding gas? See gasless transactions for every method, from paymaster sponsorship and EIP-7702 to relayers and permit signatures.

Web3 Development: More Than Smart Contracts

Web3 development is often reduced to "writing a smart contract", but users never see the contract. They see a website or app, a wallet pop-up and a transaction that either works or does not. A good web3 product needs:

• A dapp frontend that explains clearly what a user is about to sign, connected through standards such as WalletConnect.
• Reliable access to the chain through well-managed RPC endpoints, with fallbacks when a provider fails.
• A backend that indexes events, so your app can show balances and history instantly instead of querying the chain on every page load.
• Admin and monitoring tools, so your team sees what happens on-chain and can act when something is off.

Because we build all of these, the contract and the software around it are designed together rather than glued together at the end.

Chains We Build On

EVM chains: Ethereum mainnet when security and liquidity matter most, and layer 2 networks such as Base, Arbitrum and Optimism, or Polygon, when users make many small transactions. Contracts are written in Solidity and can usually run on several of these chains.

Solana: very fast and cheap transactions, with programs written in Rust. A strong fit for high-volume applications, with its own programming model and pitfalls.

We help you choose based on your users, the liquidity you need and the cost per transaction, not on what is fashionable.

Recent Blockchain Work

• Secondary token launch and tokenomics redesign on Base: a complete redesign of an existing token's economic model, rebuilt in Solidity, with a fair airdrop for existing holders, vesting schedules and a structured liquidity approach.
• USDC-denominated cross-chain trading app: a reworked trading execution layer so users trade across chains in USDC only, using EIP-712 typed signatures and robust RPC infrastructure.

Choosing a Blockchain Development Company

Whoever you choose, these are the questions worth asking:

• How is the code tested and reviewed? Look for unit and fuzz tests, an internal security review and a clear view on independent audits.
• Who holds the keys after launch? Admin rights should end up with you, ideally in a multisig, not with the developer.
• Who owns the code? Make sure ownership of the source code is set out in the contract.
• Can they build the off-chain parts? Frontend, backend, indexing and monitoring are usually more work than the contracts themselves.
• Will they tell you when you do not need a blockchain? A good partner says so, even if it means a smaller project.

Frequently Asked Questions about Blockchain Development

Start Your Blockchain Project

Tell us what you want to build, for which users and on which chain if you already know. We will help you sharpen the idea, flag the risks and decide what belongs on-chain and what does not.

Book a free call about your blockchain project