How to build a blockchain project: decisions and stages

A blockchain project combines a business need with a system for sharing and verifying information between participants. It might record transactions, represent an asset or coordinate a process across organizations. Turning that idea into a product requires defining each participant’s role and connecting the new solution to existing systems.

The first decision is whether the process needs a shared ledger and what improvement it should deliver. That provides a basis for comparing architectures, defining a pilot and organizing development. A permissioned database may be sufficient in some cases; the choice should follow the project’s needs.

1. Define the problem and a success measure

Identify users, participating organisations and information disputes. For supply-chain tracking, distinguish evidence that someone recorded a delivery from evidence that the goods arrived in good condition. The latter requires physical controls and accountable people, even when the former is anchored on a network.

Agree on an outcome before coding: reconciliation time, recording errors or the effort required to verify evidence. Define an exception process too. A pilot that does not account for errors and exceptions has not yet demonstrated an operable product.

2. Decide what belongs on-chain and off-chain

Contracts can share authorisation and transfer rules; documents, search and personal data usually need other systems. Ethereum's contract anatomy guide distinguishes persistent state from functions executed through transactions.

Map the complete path: interface, wallet or signature, RPC node, contract, storage and integrations. Record who operates each component and what happens when it fails. This describes dependence on providers and administrators more clearly than a generic “decentralised” label.

3. Choose a network and tools against measurable requirements

Compare participation permissions, finality, costs under load, privacy, tooling and team experience. An EVM network can reuse Solidity expertise, but compatibility does not make bridges, governance or operating conditions identical.

Test representative operations before choosing. Include rejected transactions and usage spikes; average fees do not explain the cost of an entire workflow. Ethereum's gas documentation explains how execution work and gas prices contribute to cost.

4. Issue a token only when it has a purpose

Not every blockchain project needs its own token. An evidence registry can work without issuing an asset, while a payment system can use an existing one. When a token is necessary, define rights, restrictions, responsibilities and recovery conditions before selecting a standard.

Legal classification depends on the product, activities and jurisdiction. In the EU, MiCA does not replace all financial regulation. The CNMV explains its scope and authorisation framework. Regulatory analysis should accompany design rather than arrive after implementation.

5. Build a pilot that exposes failures

• Specify permissions and properties that must always hold.
• Test contracts and integrations with failures, boundary cases and unexpected data.
• Document how the system can change and who can authorise changes.
• Independently assess components that hold value or authorise critical operations.

An audit is not the end of the project: findings need remediation and the corrected version needs checking. Keep requirements, code, tests and reports connected so that deployment remains traceable.

What a pilot should demonstrate before expansion

For a shared goods register, a pilot could follow one delivery between a manufacturer, carrier and recipient. Each actor records only its own events, and the system makes discrepancies identifiable. The test would aim to reconstruct the journey from attributable evidence, rather than establish that every submitted fact is true.

Include a disputed receipt, a correction and temporary participant unavailability. Define how the original event is preserved and who may append a correction. If every exception requires untraceable manual database edits, the pilot has not demonstrated the property the shared register was intended to provide.

Before production, compare this journey with a conventional alternative using the same cases and criteria. Record the effort needed to integrate existing systems and handle exceptions. The evidence may justify expansion, a narrower scope or omitting a chain altogether.

Pilot closure should deliver tested requirements, known limits and an operating budget. The next investment can then build on what was learned about the process instead of treating a technical demonstration as a product ready for every participant.

6. Launch with ownership and continuity

Prepare monitoring, backups of recoverable data, key management and incident response. The interface should explain transaction states and prevent users from repeating an operation that is still pending.

Deliverables include code, documentation, infrastructure access and operating procedures. At Metlabs, custom blockchain development starts with that complete architecture and a scope the team can test and maintain.