“One of the pioneering firms in web3 solutions, digital assets and tokenization, recognized for its innovation and solid reputation across Spain and Latin America.”
Jorge CorredorLawyer, Rincón Cuéllar & Asociados
Smart contract development. Tested before mainnet.
We are a smart contract development company. We design and build your product's contracts with permissions, tests and a security review before deploying to Ethereum and EVM networks.
They trust Metlabs with their blockchain projects
Smart contracts
What is smart contract development?
It is designing, writing and testing the code that enforces your product's rules on the network. A smart contract cannot be patched like a website, so you decide what goes on-chain, who can do what, how it is upgraded and how it is tested before it moves real value.
$220B+
in value locked on OpenZeppelin Contracts
OpenZeppelin · 2026
88%
market share across top EVM assets
OpenZeppelin · 2026
$3.4B+
stolen in crypto asset attacks in 2025
Chainalysis · 2025
What's included
What our smart contract development services include.
Every piece answers a question your product has to handle in production: who operates it, what happens when something fails and how you prove the code does what it says.
Contract architecture
Roles, permissions, events and the line between what lives on-chain and what stays in your systems.
Solidity development
Code built on audited OpenZeppelin standards, readable and documented for whoever maintains it.
Testing and fuzzing
Unit tests, fuzzing and invariants with Foundry on the edge cases that move value.
Security review
Static analysis with Slither and internal peer review before any external audit.
Gas optimization
We measure the cost of every function and reduce it without losing clarity or checks.
Verified deployment
Multisig deployment, source code verified on the explorer and a plan for day-two operations.
Architecture decision
Immutable or upgradeable smart contract?
It is the first design decision and it shapes trust, operations and cost. An immutable contract never changes. A proxy lets you fix the logic, in exchange for governing who can do it.
| Criterion | Immutable | UUPS proxy | Transparent proxy |
|---|---|---|---|
| Who changes the logic | Nobody. A change means deploying a new contract and migrating. | The authorized role inside the implementation itself. | A separate admin on the proxy. |
| Cost per call | The lowest: no intermediate layer. | One extra delegation, with a lighter deployment. | One delegation plus the admin check. |
| Main risk | A logic bug cannot be fixed. | An upgrade without the upgrade function locks the contract. | A compromised admin key. |
| Typical fit | Fixed-supply tokens and stable logic. | Products that evolve under clear governance. | Systems that separate administration from logic. |
When there is a proxy, upgrade authority goes to a multisig with a timelock, never to a single key.
Methodology
How we develop your smart contracts.
Four phases, each with a concrete deliverable. We decide what goes on-chain before writing code, and no contract reaches mainnet without tests and review.
An architecture document with the flow of every operation, the roles and what stays off the network.
We design the screens that sign against the contract so every user action is clear.
Solidity contracts on OpenZeppelin, with every function documented and reviewed in a pull request.
Fuzzing and invariants with Foundry, Slither analysis and multisig deployment with verified code.
Tools for contracts you can prove.
Solidity on audited libraries, testing with Foundry and Hardhat, and the EVM networks we deploy to.
- Solidity
The smart contract language for verifiable rules on EVM networks.
- OpenZeppelin
Audited Solidity contracts for tokens, access control and upgradeable systems.
- Foundry
Solidity tests, invariant fuzzing and command-line tooling for EVM networks.
- Hardhat
An environment to compile, test and deploy contracts on EVM networks from Node.
- Ethereum
EVM contracts, tokens and final settlement on an open Proof of Stake network.
- Arbitrum
Arbitrum One: EVM execution and layer 2 tooling on top of Ethereum.
Use cases
Where we apply smart contracts.
A smart contract adds value when several parties need the same rules, enforced the same way for everyone and verifiable afterwards.
Conditional payments and escrow
Funds released only when an agreed milestone is met, with a record of every step.
Blockchain for Banking & Finance
Parametric insurance
Policies that pay out when an external data point, verified by an oracle, is met.
Blockchain for Insurance & Insurtech
Traceable records
Timestamped evidence and permissions an auditor can check without asking for access.
Blockchain for Legaltech & Compliance
Rights and royalties
Automatic splits between rights holders every time a digital right is used or resold.
Blockchain for Music & Media
Reviews
What do our clients think of Metlabs?
“We structured the tokenization of real estate projects with them, and I value the team's ability to understand our corporate needs and genuinely solve them.”
Joan MejíaManager, GLOBYNE
“They advised us on the feasibility of tokenizing real estate assets in Uruguay with direct, cordial treatment. A professional team, responsive and always available.”
Álvaro Silva SantamaríaCEO, Sp Inmuebles
“Great professionals at structuring tokenized projects, with technical command and attention to detail that inspire full confidence at every stage of the work.”
Francisco BetancourtVerified Google review
“As a blockchain lawyer, I value their experience and professionalism in consulting and executing tokenization projects. Technology partners you can fully trust.”
Vanessa RivasBlockchain lawyer, El Salvador
“Great professionals, very attentive to their clients and always mindful of every detail. Working with their team has been a genuine pleasure from start to finish.”
CriptorentVerified Google review
“A very professional yet approachable company that empathizes with your doubts and needs. Highly recommended for entrepreneurs with a tokenization project.”
Javier EspasaTokenization entrepreneur
“Exceptional in every sense. From legal support I value their rigor and transparency: working with Metlabs means professionalism, innovation and security.”
Pedro A. Agúndez MéndezGoogle Local Guide
“Excellent service across blockchain development, asset tokenization and consulting. A very professional team that I recommend wholeheartedly, without reservation.”
José Luis DíazVerified Google review
“I have worked with them on several projects and they are very professional. A guarantee that everything turns out perfectly. Without a doubt, 100% recommended.”
Ignacio Fernández JiménezVerified Google review
“One of the pioneering firms in web3 solutions, digital assets and tokenization, recognized for its innovation and solid reputation across Spain and Latin America.”
Jorge CorredorLawyer, Rincón Cuéllar & Asociados
“Great professionals at structuring tokenized projects, with technical command and attention to detail that inspire full confidence at every stage of the work.”
Francisco BetancourtVerified Google review
“A very professional yet approachable company that empathizes with your doubts and needs. Highly recommended for entrepreneurs with a tokenization project.”
Javier EspasaTokenization entrepreneur
“I have worked with them on several projects and they are very professional. A guarantee that everything turns out perfectly. Without a doubt, 100% recommended.”
Ignacio Fernández JiménezVerified Google review
“We structured the tokenization of real estate projects with them, and I value the team's ability to understand our corporate needs and genuinely solve them.”
Joan MejíaManager, GLOBYNE
“As a blockchain lawyer, I value their experience and professionalism in consulting and executing tokenization projects. Technology partners you can fully trust.”
Vanessa RivasBlockchain lawyer, El Salvador
“Exceptional in every sense. From legal support I value their rigor and transparency: working with Metlabs means professionalism, innovation and security.”
Pedro A. Agúndez MéndezGoogle Local Guide
“They advised us on the feasibility of tokenizing real estate assets in Uruguay with direct, cordial treatment. A professional team, responsive and always available.”
Álvaro Silva SantamaríaCEO, Sp Inmuebles
“Great professionals, very attentive to their clients and always mindful of every detail. Working with their team has been a genuine pleasure from start to finish.”
CriptorentVerified Google review
“Excellent service across blockchain development, asset tokenization and consulting. A very professional team that I recommend wholeheartedly, without reservation.”
José Luis DíazVerified Google review
Team
In-house blockchain development team
Metlabs is a blockchain development company based in A Coruña, Spain. An in-house team covers every part of the project, from product and engineering to infrastructure and legal fit. The people who design your architecture write, test and deploy the code.
Meet the team- Projects in production
- +30
- In tokenized assets
- +$40M
- In‑house development
- 100%
Isaac González
Head of Innovation
Carlos Peña
Full Stack Engineer
Pablo Castro
DevOps Engineer
Helena Ramos
Product Designer
Javier Yáñez
Legal
Security
Security in smart contract development
Every delivery goes through the same checklist before it reaches mainnet. What changes between projects is the depth of each control, because an MVP does not carry the same risk as a contract that holds third-party funds.
Before mainnet
- Roles and permissions defined for every critical function
- Unit and invariant tests, and fuzzing on the logic that moves value
- Static analysis and peer review of every change
- Multisig and timelock on administration when the risk justifies it
- Custody and rotation of the deployment keys agreed
- External audit when the value at risk requires it
We work with leading audit firms
FAQ
Smart contract development questions
It depends on scope, not on lines of code. The main drivers are how many contracts interact, the integrations with your systems, whether the logic is upgradeable and whether an external audit is required. We quote a fixed scope after the specification phase, once those decisions are made.
We start with a specification of roles, flows and what stays off-chain, then write the contracts in Solidity on OpenZeppelin. Every function gets unit tests, fuzzing and invariants with Foundry, static analysis with Slither and an internal review before a testnet and then a multisig mainnet deployment.
Yes. When the value at risk justifies it, we prepare the code and documentation for an external audit firm and fix its findings before mainnet. Our internal review runs first, so the external audit focuses on design risks rather than basic errors.
Blockchain development
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Let's build the rails for your product.
Tell us what your contract has to do and who will operate it. We start with the specification and the architecture decisions.
