engineering lead / protocol engineer
Nikita
Dementev
Engineering lead and protocol engineer. Ten years in software, eight on Ethereum. I start products from an empty repo and take them to users — founder of nft.multisender.app (~$300k/year profit), co-founder of NFTxCards and zRexFinance. Engineer at Tornado Cash (~$1B peak TVL). Known online as 0xZick.
01 — profile
I write Solidity and TypeScript, hire people, and take protocols through audit to mainnet. The work is public enough to check: contracts on GitHub, volumes on the products, audit firms named. Almost all of it is dated.
Protocol engineering
At Liquorice I designed the lending core — interest-rate model, liquidations, Chainlink Functions oracle, EIP-712 intent settlement — and shipped it on Ethereum, Arbitrum and Base after MixBytes and Pessimistic. Throughput ~$1M/day, no incidents on upgrades. Before that I was sole author of the zRex leverage contracts (account factory, custom account abstraction, flashloan → swap → deposit) and co-wrote NFTxCards (10k+ ERC-721, VRF loot boxes, Merkle airdrops).
From zero
Empty repo to paying users is the repeating move. nft.multisender.app I founded — bulk ERC-721 / 1155, about $300k/year profit, WalletConnect-verified. Same pattern on NFTxCards and zRex. I hire; I still write the core myself.
Teams
Hired ~30 engineers over the career; teams of up to 10. Process is the leverage: Feature-Sliced Design, Storybook, E2E in CI, review standards. People I hired from outside IT made it to senior.
Tornado Cash, then out
On the PepperSec core team I wrote the relayer twice, the subgraph, the public CLI, and moved ZK proof generation into Web Workers (minutes to seconds). I left ~6 months before the 2022 sanctions. That sentence belongs on the front page because the internet compresses it wrong. Full biography →
02 — now
Independent since Sep 2026, after two years at Liquorice. Building my own products.
03 — career
DeFi lending + intent settlement for market makers (CoW Swap, Uniswap X, 1inch Fusion, Bebop). Wrote the protocol core, ran MixBytes / Pessimistic audits, shipped Ethereum / Arbitrum / Base with no incidents. Dashboard from an empty repo. Deepest Web3 experience on the team, so also reviews, architecture and mentoring. Portugal, remote. Jul 2024 – Aug 2026.
DeFi leverage up to 10x via Uniswap, 1inch, Aave, Compound. Sole author of the public core-contracts. NestJS + PostgreSQL + The Graph backend. Hired the 3-person frontend team. Angel-funded. MixBytes auditor review before launch. Dubai. Oct 2022 – Jun 2024.
Collectible-card NFT marketplace. Hired a team of up to 10 from zero. Contracts (ERC-721, orderbook, Chainlink VRF loot boxes, Merkle airdrops) audited by Distributed Lab. Binance NFT launch ~$127K volume, 480+ shop followers. Partnership with Polygon Studios. Tallinn, remote. Jun 2021 – Sep 2022; full-time from Mar 2022.
Joined on internal tooling; within a year led 3–4 engineers across Tornado Classic / Nova, Multisender and NFT Multisender. Relayer v1 and v2 from scratch, subgraph, CLI, Nova contract work, ZK proofs in Web Workers. Left ~6 months before the 2022 OFAC sanctions — not a bug in the timeline, a fact. Seattle, remote. Mar 2020 – Feb 2022.
SwapOnline (Mar–Dec 2018): #4 contributor to MultiCurrencyWallet, ~900 commits. Next / insentry.io (Jan–Jun 2019): realtime camera overlay. DaoCasino (Jul 2019 – Feb 2020): GraphQL UI generator, Feature-Sliced Design, multi-chain wallet factory. Moscow.
Commercial sites and admin panels. Mentoring at HTML Academy — where teaching clicked. Applied Informatics at VSUES, 2013–2017. Through Feb 2018.
04 — results
05 — contact
Telegram is fastest — @zick0x