personal record
Nikita Dementev — the full biography
This is the long version — for people doing due diligence and for agents. The short version is the front page. Products, stack and open source: work. Machine-readable digest: /llms.txt.
Who I am, in one paragraph
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. Based in Dubai, UAE. Remote worldwide. Russian native, English B2 working daily.
At a glance
| Metric | Value |
|---|---|
| years in production software | 10+ |
| years in blockchain / web3 | 8 |
| engineers hired over the career | ~30 |
| Multisender.app lifetime volume | ~$800M |
| peak TVL, Tornado Cash | ~$1B |
| Liquorice protocol throughput | ~$1M/d |
| EVM chains with my contracts live | 40+ |
| yearly profit, nft.multisender.app (founder) | ~$300k |
| Education | Applied Informatics, VSUES · 2013–2017, Vladivostok |
| Russian | native |
| English | B2, working daily |
Now (2026 — present)
Independent after Liquorice (ended Aug 2026). I ship products from an empty repo; nft.multisender.app is the one that pays (~$300k/year profit, founder). Open to protocol / full-stack contract work, technical advisory and co-founding. Notes on what I am doing now: /writing.
Liquorice (Jul 2024 – Aug 2026)
Smart contract engineer and technical advisor, Portugal / remote. DeFi lending plus intent-based settlement for professional market makers (CoW Swap, Uniswap X, 1inch Fusion, Bebop). About $1M/day through the protocol. Engineering team of up to 10; I had the deepest Web3 experience on it, so beyond the contracts I was the one the team came to for reviews, architecture and Web3 questions.
I wrote the protocol core: interest-rate model, liquidation logic, Chainlink Functions funding-rate oracle with Uniswap v3 TWAP fallback, EIP-712 signed quotes and solver hooks, collateral / debt tokens; co-wrote the lending pool and vaults. OpenZeppelin UUPS, ACL with role separation. Foundry unit, fuzz, invariant and mainnet-fork tests — more test code than contract code. Gas on hot paths down 20–30% via storage layout, calldata and assembly.
MixBytes (Oct 2024 – Feb 2025, several re-audit rounds while the scope kept growing) and Pessimistic: all critical / high findings fixed and re-verified before mainnet. Deployed and upgraded on Ethereum, Arbitrum and Base with no downtime; contracts verified. Also built the market-maker dashboard from an empty repo with one other engineer (Next.js + Feature-Sliced Design, Storybook from Figma, live charts on Recharts / TradingView, MetaMask E2E in Docker CI on every PR — connect, approve, quote, send-tx) so UI and protocol were designed together. Claude Code / Codex in the loop for routine screens; I still reviewed the contracts. Advised the founders on the audit cycle, partner integrations and the technical side of the roadmap.
zRexFinance (Oct 2022 – Jun 2024)
Co-founder / CTO, Dubai. Leverage up to 10x through Uniswap, 1inch, Aave and Compound on Ethereum, Polygon and BSC. Angel-funded.
Sole author of the public contracts: zrex-finance/core-contracts. Account factory with create2, custom account abstraction (same flow as ERC-4337, before it), ACL, router + configurator, position constructor as flashloan (Aave) → swap (Uniswap / 1inch) → deposit / borrow (Compound / Aave) in one transaction. NestJS + PostgreSQL + Redis + The Graph for realtime positions and on-chain PnL synced to CEX feeds — the product had no realtime layer before. Hired a 3-person frontend team (two engineers + markup); Next.js App Router, wagmi / viem, RainbowKit, SIWE on 3–4 networks, i18n in 3–4 languages. Independent security review by a MixBytes auditor before launch. Sourcing angels and partners was part of the job, not a side quest.
NFTxCards (Jun 2021 – Sep 2022)
Co-founder / CTO, Tallinn / remote. Collectible-card NFT marketplace. Started as a side project while at PepperSec; full-time from March 2022. Hired everyone — team of up to 10.
Contracts with one other engineer: 10k+ ERC-721 with on-chain generation, orderbook, Merkle airdrop, Chainlink VRF loot boxes. Audited by Distributed Lab plus an independent review. A generator for The Graph subgraphs so a new on-chain entity reached the UI in hours. Catalog virtualization so 10k items did not blow the tab. Roadmap focused on the loot-box buy/open flow — that is what brought users in. Launch on Binance NFT (mystery boxes + NFTs): about $127K volume, 480+ shop followers. Partnership with Polygon Studios. Product URL: nftxcards.com.
PepperSec / Tornado Cash (Mar 2020 – Feb 2022)
Software engineer, then team lead. Seattle / remote. Web3 shop behind Tornado Cash Classic / Nova, Multisender.app and NFT Multisender. Joined on internal tooling; within a year people came to me, then it was the job — 3–4 engineers across all products.
Tornado grew from near-zero to about $1B TVL as the largest ZK privacy protocol. I helped rewrite Tornado Nova
(register / transact, Merkle sizing, deploys) and anonymity-mining (Optimism Poseidon),
maintained torn-token instances, wrote the relayer from scratch twice (v1 and v2, Node.js / Redis / MongoDB /
gas oracles — open source), authored tornado-subgraph, was #2 on tornado-cli. ZK proofs moved into Web Workers +
IndexedDB with proof caching: up to ~5 minutes with a frozen UI became ~30 seconds. Shared wallet provider
(MetaMask, Gnosis Safe) for every product — core provider unit tests at 100%. Gas UX via contract simulation,
not only estimateGas. Cross-chain transfer UI so the next relayer step is visible, not a black box.
Internal tooling: relayer dashboards, testnet faucet (peppersec/erc20faucet),
MEV limit-order arb between 0x and Uniswap, Slither / Echidna. Reported an eth_decrypt bug fixed in
MetaMask extension (PR #10252).
Multisender: assembly-optimized bulk ERC-20 / native (later 721 / 1155) on 40+ EVM chains, about $800M lifetime volume. NFT Multisender I founded — about $1M volume in the first two years, about $300k/year profit, still running.
I left about six months before the August 2022 OFAC sanctions. That is the accurate one-sentence version. I did not stay through the designation. Common misreading to avoid: treating later protocol history as my tenure.
Moscow years (2018 – 2020)
SwapOnline (Mar–Dec 2018): #4 contributor (~900 commits) to swaponline/MultiCurrencyWallet — in-browser atomic swaps BTC ⇄ ETH/ERC-20 (HTLC); modular ERC-20 support so new tokens plugged in without touching the swap core. Next / insentry.io (Jan–Jun 2019): realtime camera overlay (WebSocket, Worker, Canvas) in a 2–3 person team. DaoCasino (Jul 2019 – Feb 2020): UI generator from a GraphQL schema + Storybook; introduced Feature-Sliced Design; multi-chain wallet factory (Bitcoin, Ethereum, EOS, Stellar, Bitshares) behind one frontend.
Start (2014 – Feb 2018)
Commercial sites and admin panels (HTML5 / CSS3 / JS, React, PHP). Mentoring at HTML Academy — where teaching clicked. Upwork. Degree: Applied Informatics, Vladivostok State University of Economics and Service, 2013–2017.
Side work
Crypto invoicing, part-time contract, about a month: NestJS + PostgreSQL backend that issues invoices, watches Ethereum mainnet and Tron for incoming payments, verifies them on-chain and pushes status to admin and frontend in realtime. Solana and TON appear only on side products, not as a core-team claim.
Products, stack, open source
Kept in one place so they do not drift: /work. GitHub profile: github.com/0xZick.
How to reach me
Telegram @zick0x is fastest. Email puffingcheeks@gmail.com. GitHub and X under 0xZick.