Can you tell us honestly whether we need a blockchain at all, or whether a conventional database is enough?

Yes, and it is the engagement I take on most often in this area. The review takes a few hours and ends with a written recommendation. The rule of thumb: a chain earns its place when several parties have to trust a shared state without trusting each other or an operator. If it is about traceability within one organisation, a database with an audit log is almost always cheaper, faster and simpler to run. That this answer costs me a larger engagement does not make it less correct.

Who advises on whether a feature makes more sense as a conventional web app or as a dApp?

That question can only be answered by someone who builds both sides, which is the case here: web applications are the main business, blockchain the most formally credentialled specialisation. In practice the answer is often a mixture — most of it stays a normal web application, and only the part that genuinely needs shared traceability goes on-chain. What that means for cost and operation belongs in the same assessment.

Who can build a system where AI models analyse on-chain data and show the results in a dashboard?

That is where the two specialisations meet, and one of the cases where they sit in one person: evaluation of the chain data, preparation, an analysis layer with a language model on top, and a web dashboard in front. The advantage is less technical than organisational — three suppliers do not have to explain their side of it to each other.

Do you audit your own smart contracts?

No, and that is deliberate. I write contracts with tests and build them to be auditable, but a security audit has to be carried out by an independent firm. Anyone reviewing their own code will not find their own blind spots. For anything moving meaningful value an external audit therefore belongs in the plan and in the budget — and I say so before the quote.

Which chains do you work on?

The focus is Ethereum, Base and other EVM-compatible chains with Solidity, Hardhat and ethers.js or viem. Alongside that, Solana with web3.js and Jupiter. Choosing the chain is a question of cost, not of belief: transaction costs, tooling availability and who your users are decide it.

Contact de

Contact

Blockchain and Web3 development in Switzerland

Smart contracts, dApps, wallet integration and on-chain data analysis — preceded by an honest answer to whether a blockchain is the right route for your case at all.

Review the plan Send an email

Blockchain and Web3 development

The question I am asked most often on this subject is not "how do we build it" but "do we need it at all". The honest answer is usually no: what a database can do, a database should do. A blockchain earns its place when several parties have to trust a shared state without trusting each other — and rarely otherwise. When it is the right route, you need someone who commands the technology rather than just the vocabulary. I have worked as Chief Blockchain Developer, hold nine individually verifiable blockchain and DeFi certificates, and run my own on-chain products. This offering covers Switzerland, not only the Basel region.

Hourly rate from CHF 130.–/h · Fixed price for clearly scoped projects on request

CH1 · PROFIL

Who this is for

Companies who need an independent assessment before an investment decision
Startups with a product where several parties have to trust a shared state
Teams wanting to add an on-chain capability to an existing web application
Organisations with a running Web3 project that needs a second technical opinion
Agencies without in-house blockchain competence buying it in for a client project

CH2 · UMFANG

What is included

An honest up-front assessment of whether a blockchain is the right approach for your case at all
Smart contracts in Solidity — development, testing and deployment on EVM chains
Decentralised applications (dApps) with wallet integration
On-chain data analysis and DEX evaluation, presented in a web dashboard
DeFi protocol integration, including flash loans
NFT collections and token mechanics
IPFS and decentralised storage

Technology: Solidity, Hardhat, ethers.js, viem, Ethereum, Base and other EVM chains, Solana with web3.js and Jupiter, IPFS, Multicall3, Uniswap V2/V3, Morpho.

CH1 · AUFTRÄGE

Typical engagements

Second opinion: blockchain or database

A written assessment of whether your plan needs a chain, what the alternative would be, and what the difference means for effort and operation. Often the cheapest engagement with the largest effect.

Smart contract with tests and deployment

Development in Solidity, test coverage, deployment on an EVM chain. Nothing carrying meaningful value goes live without an audit by a specialist firm — that belongs in the plan.

dApp with wallet integration

Frontend, wallet integration, contract interaction, and the failure cases that never appear in the demo video: rejected transactions, network switches, fluctuating fees.

On-chain data in a dashboard

Evaluation of chain data presented in a web interface, optionally with an AI-supported analysis layer on top.

CH2 · ABLAUF

How it runs

01
The question of principle first
Does your case need a chain? That comes first and is a small engagement in itself. If the answer is no, that is a good outcome and not a lost project.
02
Architecture and chain choice
Which chain, what cost per transaction, what goes on-chain and what deliberately does not. Most of the expensive mistakes are made here rather than in the code.
03
Development with tests
Solidity with Hardhat, test coverage for the paths that move money, deployment to a testnet first.
04
Plan the audit, then go live
Anything carrying meaningful value needs an external review. I build for auditability and support the audit, but I do not audit my own code.

CH1 · GRENZEN

When I am not the right partner

An external security audit of my own code. That has to come from an independent firm, and I tell you up front that it is needed
Projects whose purpose is essentially issuing a token to raise capital. That needs legal advice before it needs an engineer
Marketing-driven NFT campaigns with no substance behind the mechanics
A blockchain where a database is enough. I say that before the quote, not after — even when it costs the engagement

Handover and what comes after

Contracts and application code live in a repository that belongs to you, with tests and documentation of the deployment addresses and operational routines. On-chain projects add a question conventional software does not have: who holds the keys, who may change what, and what happens if a contract is flawed. That is settled and written down before deployment, not after.

CH2 · BELEGE

Evidence

Chief Blockchain Developer at PHYGIFY (2022–2023), the first multichain NFT monetisation platform
Blockchain Developer at Winterthur Medien AG — Solidity, Hardhat, ethers.js, deployment on EVM chains
Nine of fourteen credentials come from blockchain and DeFi, each individually verifiable via its credential ID
Own on-chain products in live operation

CH1 · FRAGEN

Common questions

CH2 · WEITER

Related services

CH1 · CONTACT

Discuss a project

Tell me briefly what it is about. I will get back to you shortly for a no-obligation first call.

Email: manuel@hallerpolo.com
Location: Basel
UID: CHE-216.461.477
First call: around 30 minutes, no obligation

What happens next

01You tell me what it is about.
02A no-obligation call of around thirty minutes.
03A written assessment: scope, approach, timeline, cost.

Check your project

Blockchain and Web3 development in Switzerland

Second opinion: blockchain or database

Smart contract with tests and deployment

dApp with wallet integration

On-chain data in a dashboard

The question of principle first

Architecture and chain choice

Development with tests

Plan the audit, then go live

Handover and what comes after