Cryptographic key management and multi-chain transaction infrastructure.

I work at the layer most engineers abstract away — raw keys, raw transactions, raw signatures — across Bitcoin, EVM and Tron.

Named author of ERC-7208 · status Final

A standard that separates on-chain data storage from the logic that governs it, so tokenized assets stay interoperable across current and future token standards. I contributed from early Solidity test coverage through production contract work.

Keys and signatures

• EC key management and hierarchical derivation (BIP-32/44, SLIP-10)
• ECDSA and Schnorr signing, raw signature handling
• PSBT construction and multi-party signing coordination
• HSM-backed key lifecycle, multisig

Bitcoin

• Raw transaction construction and UTXO management
• Legacy, SegWit and Taproot output and spend types
• Nested SegWit → Taproot migration

EVM and smart contracts

• Account abstraction and EIP-7702 delegated execution with sponsored gas
• Ethereum signature standards — EIP-191, EIP-712, EIP-1271, and Safe encoding
• ERC-2771 meta-transactions, ERC-4626 vaults
• Proxies, Diamond, factories, deterministic deployment
• DEX and liquidity-aggregator contracts, Uniswap V4 hooks
• Cross-chain via LayerZero, plus a bridge built from scratch

Security

• Internal audits and third-party audits of external protocols
• Remediation cycles with external auditors
• Foundry (unit, fuzz, invariant), Slither

Solidity TypeScript Cairo Foundry Hardhat Node.js NestJS PostgreSQL GraphQL Docker The Graph Bitcoin EVM Tron Solana StarkNet Hyperledger Besu

LinkedIn · berbesidaniel@gmail.com

Open to remote contract work worldwide, and to relocation.