How Web3 products differ from conventional ones
In a conventional service, all data lives on the company's servers, and a bug can be fixed with a single update. In blockchain, part of the logic lives in smart contracts that are very hard or impossible to change once deployed. A bug in a contract can cost users real money.
The second difference: users are responsible for their own assets. They sign every transaction with a wallet, pay a network fee, and wait for confirmation. If the interface doesn't explain what's happening, people can't tell whether the transaction went through, so they repeat it or leave the product.
Typical project goals
- Launch a token or NFT collection with a website, sales, and an owner dashboard.
- Make a crypto service accessible to newcomers who have never used a wallet.
- Add blockchain features to an existing product: crypto payments, in-game digital items, user rewards.
- Turn on-chain data into a clear dashboard for analytics, reporting, or monitoring.
- Turn a hackathon prototype into a real product that can handle real users and real load.
What we build
Decentralized apps for swaps, staking, DAO voting, games, and giveaways, where the key rules are written into a smart contract anyone can verify.
Smart contracts for tokens, NFTs, sales, reward distribution, and access to product features.
Crypto wallets and services for storing, exchanging, and transferring crypto, including mobile apps.
Digital asset marketplaces where users buy and sell NFTs or in-game items. We cover the general logic of multi-vendor platforms on our marketplace page.
Analytics services that collect on-chain data and show fund flows, wallet balances, and contract activity.
What goes on-chain and what stays on the server
One of the most common mistakes is putting everything on the blockchain. Every on-chain operation costs a fee and takes time, and the data is visible to everyone. So we keep on-chain only what truly needs transparency and independence from the company: asset ownership, distribution rules, payments.
Profiles, settings, search, notifications, content, and analytics run on a regular server. A dedicated service tracks network events and updates the database so pages load fast instead of waiting on the blockchain.
Choosing a network
Ethereum has the largest ecosystem of wallets and services, but its fees can be noticeable for small transactions. Networks like Polygon work with the same tools and are usually cheaper. Solana and TON have their own development tools, wallets, and audiences; TON in particular is closely tied to Telegram.
We don't push a particular network; we choose it for the product: where your users are, which wallets they already have, how many transactions they'll make, and how much the cost of each one matters. If the product needs to run on several networks, we build that into the architecture from day one, because adding a network later is much harder.
Transactions people understand
Confirming a transaction can take anywhere from a few seconds to much longer, and sometimes a transaction fails due to an insufficient fee or a price change. For users, this is the most stressful moment, so we design it separately.
- Before signing, we show exactly what will happen, the amount to be charged, and the estimated network fee.
- After submission, users see the transaction status and a link to it in the block explorer.
- Errors are explained in plain language with a hint on what to do next, not a technical code.
- Clicking again doesn't send a second transaction while the first is still processing.
Smart contract security
We keep contracts simple with minimal admin privileges, cover every scenario with tests, and verify them on a testnet. For contracts that handle significant funds, we recommend an independent audit by a specialized firm, and we prepare the code and documentation for it.
Security around the contract matters just as much: protecting admin keys, restricting access to the control panel, and monitoring suspicious transactions.
Things to keep in mind
Legal landscape. Rules on crypto assets, tokens, and customer verification vary by country and keep changing. Work through the legal side with your attorneys before launch, and we'll build the required checks, such as KYC, into the product.
Newcomers in your audience. The broader the audience, the more attention explanations, hints, and the option to sign in without a wallet at first require.
Community. Web3 projects live on Telegram, X, and other community channels. Your website and product should connect to these channels, and updates should be clearly explained to the community. Our social media marketing can help with this.
Portfolio examples
Promodex's blockchain and crypto projects include CryptoXpress, Crypto Monitoring, Sheesha Finance, and YAY Games. We cover digital financial services more broadly on our fintech page.
What affects the cost
- Smart contract logic: a simple token or a complex system of rewards, sales, and voting.
- Number of networks: a single network or support for several with different wallets.
- Backend: whether you need profiles, an admin panel, and on-chain data collection and analytics.
- Platforms: web only, or also a mobile app or wallet.
- External contract audit: its cost is set by the audit firm and should be budgeted separately.
We split the project into phases and agree on the scope of each, so you always see where the budget goes.
FAQ
Does my product need a blockchain? Not always. If transparency and asset ownership don't matter to your users, a regular database will be cheaper and faster. We'll tell you so honestly.
Can a smart contract be changed after launch? Only if upgradeability is built in from the start. But then users have to place more trust in the administrator, so we make that decision together, weighing the risks.
Can users sign in without a wallet? Yes. You can offer email or social sign-in and create a wallet for the user later, when they need it.
Do you handle token exchange listings? No. We're responsible for the technical side of the product; listings and the token's financial model are up to your advisors.
Why Promodex
Promodex is an agency that has delivered 750+ digital projects since 2015. Our in-house designers, developers, and marketers work on the product together, with no outsourcing, so the interface, smart contracts, and backend fit together as one whole. We're honest about where blockchain is needed and where it isn't, plan the work transparently, and support updates and growth after launch.
