Spec-driven.
Invariant-tested.
Solvency first.
We design, build and review smart contracts for DeFi protocols, asset tokenization and other blockchain products, from vaults, lending markets and AMMs to oracles and security tokens. We also build bespoke tokenization platforms, with your company's website, app and integrations. Every system starts from the invariants it must hold and is tested against them, phase by phase, before it reaches an audit.
SOLIDITY · FOUNDRY · EVM L1/L2 · ERC-20 · ERC-721 · ERC-4626 · ERC-3643 · ORACLES
Bespoke platforms for companies that tokenize their assets or need verifiable records without a financial token.
Smart contracts for DeFi protocols, from first design to production code, and their preparation for audit.
Your company has income-producing assets. Tokenization lets you finance them with participations, from your own platform.
A company with an income-producing asset can divide it into participations and offer them to investors from its own website and app, under its brand. We build that platform to fit your business, connected to your systems and to your identity and payment providers.
Bespoke tokenization platforms for companies that finance their assets with participations. Smart contracts, website and app under your brand, management dashboard and integrations with your systems.
DLT records without a financial token. Traceability with IoT sensor data, digital product passports, verifiable credentials, document timestamping and member votes.
Tokenizing an asset divides it into participations, recorded as tokens, that investors can buy.
The lower the price per participation, the more people can take part with a small amount. The value of the asset does not change.
Illustrative model. Not an offer or a forecast of returns.
A hotel group that divides one of its buildings into participations to finance its renovation.
See the example, Hospitality and tourismA winery that finances the expansion of a vineyard with participations in that vineyard.
See the example, Food and agricultureA rental company that finances the renewal of its fleet with participations in the vehicles.
See the example, MobilityA club that finances a new court or sports hall with participations in those facilities.
See the example, Sport and leisureA DeFi protocol holds its users' funds. We design and test it so its accounts balance on every operation.
From a vault or a lending market to an AMM or a staking system, we write down the invariants the protocol must hold before any code, and check them with stateful invariant tests in every phase, until it is ready for audit.
From a single contract to a full protocol. Design and implementation in Solidity, covering DeFi protocols (vaults, lending markets, AMMs, liquidation engines and oracles), tokens, NFT collections and permissioned tokens (ERC-3643).
An independent review of your architecture, solvency invariants and threat model, before the design is locked into code.
Invariant and fuzz testing on your codebase to catch issues before your audit starts, so the auditors can focus on the deeper ones.
This is not a security audit. It prepares your code for one.
Your audit report, handled through to the auditors' fix review. We coordinate with the audit firm, triage the findings, fix them with regression tests and prepare the deployment, whether or not we wrote the code.
Ongoing senior architecture support for teams without a full-time protocol architect, covering design decisions, code reviews and the technical roadmap.
The position is above the liquidation threshold: 85% of the collateral still covers the debt. Move the slider or pick a preset to see where the line is crossed.
Roofcast, a real-estate prediction market protocol, live on a public testnet for users in Florida.
See the project, Prediction marketsMoveX, a DEX where traders take positions on volatility rather than price direction.
See the project, Volatility derivativesfija Finance, an institutional DeFi platform built on ERC-4626 vault strategies.
See the project, ERC-4626 vaultsAn open-source single-base lending market, inspired by Compound III.
See the project, Lending markets
Gustavo Martín
Founder · Protocol Architect & Senior Smart Contract Engineer
Gustavo designs and builds smart contracts for asset tokenization, DeFi protocols and other blockchain products. He is the lead smart contract engineer and protocol architect at Roofcast, and has worked on protocols such as MoveX, Dexynth, fija Finance and BeGlobal Finance.
Before blockchain, he spent three years at CERN as a fellow, building PLC and SCADA control software for the cooling and ventilation systems behind its accelerators and experiments, and nine years as co-founder and technical director of a fleet tracking and control company. That is where the experience with sensors and field data behind the traceability projects comes from. And from systems that must fail safe comes the solvency-first approach.
When you work with Tesselium, you work directly with him, from the first call to the last commit.
Cyfrin Updraft certifications in smart contract security · First prize, MERGE Madrid Web3 Hackathon 2025
Yes. A single contract, a token with vesting or an integration with an existing protocol are all welcome. Every project gets the same process, scaled to its size.
Ethereum and EVM-compatible chains, including L2 networks. Our core stack is Solidity and Foundry. We also have experience with Rust and Anchor on Solana.
No. We work on the technical side, alongside your legal advisors, who decide which rules apply to each project.
Design reviews, pre-audit hardening and audit support are fixed-price, agreed after a first look at the scope or the audit report. Development, tokenization and DLT projects are billed by milestones or by the day, and fractional architecture as a monthly retainer. Prices exclude VAT where applicable.
A design review usually takes 1 to 2 weeks and pre-audit hardening 2 to 4, depending on the size of the codebase. Development timelines are agreed per milestone.
Yes. We can join an ongoing project, review and extend existing contracts, or support your team as a fractional protocol architect.
Yes, if you need one before sharing your code or design.
Whether you want to tokenize one of your company's assets, or need a single contract, a design review before launch or ongoing architecture support, tell us what you are building.
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