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. 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
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.
01 / SERVICES
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).
Smart contracts for real-world asset (RWA) tokenization on blockchain and DLT, from permissioned security tokens (ERC-3643) to identity, compliance and wallet recovery flows. We handle the technical side, working alongside your legal advisors.
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.
02 / HOW WE WORK
03 / FOUNDER
Gustavo Martín
Founder · Protocol Architect & Senior Smart Contract Engineer
Gustavo designs and builds smart contracts for DeFi protocols and 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 company. That background in systems that must fail safe is where the solvency-first approach comes from.
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
04 / FAQ
No. It is preparation for one. We add invariant and fuzz tests, run static analysis and fix what we find, so the auditors spend their time on the deeper issues. If your contracts will hold user funds, you should still get an independent audit. After the audit, we can also handle the remediation.
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.
We build the smart contract layer, including permissioned security tokens following ERC-3643, onchain identity and compliance rules, transfer restrictions and wallet recovery. Your legal advisors define the structure of the offering, and we implement the rules they set.
No. We work on the technical side, alongside your legal advisors, who decide which regulatory framework applies and which rules the tokens must enforce.
Before the architecture is locked into code. Fixing a solvency issue in a design document takes days; fixing it after deployment can mean a migration, or worse.
Design reviews, pre-audit hardening and audit support are fixed-price, agreed after a first look at the scope or the audit report. Development and tokenization 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.
05 / CONTACT
Whether you need a single contract, a design review before launch or ongoing architecture support, tell us what you are building.
Prefer to talk first? Book a free 30-minute intro call.
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