# Crypto custody, and recovering $4M+ in stranded creditor assets from 5M+ vaults

Case study · Regulated fintech / DeFi

AI platform work paired with a decade of institutional custody and DeFi architecture: CCSS Level 3 custody at Vellum, wrapped-token launches, and $4M+ recovered for creditors during the Celsius bankruptcy.

Canonical: https://davidveksler.com/work/crypto-custody-and-recovery/
Updated: 2026-07
Primary artifact: https://vellum.capital/?ref=portfolio

- CCSS L3: custody platform (Vellum)
- 24: engineers directed (Celsius)
- $100M+: TVL wrapped-token launch
- 5M+: vaults scanned, 20+ EVM networks
- $4M+: stranded assets recovered

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## Why this case study exists

My [AI platform work at a regulated lender](/work/regulated-lender-ai-platform/) is the headline, and this page is the decade underneath it. The habits I bring to AI governance were formed somewhere a mistake moved other people's money in a direction nobody could reverse. Custody is where I learned what an irreversible action actually costs, and the lesson stuck harder than any architecture book.

## Vellum Capital: institutional custody

Co-founder of [Vellum Capital](https://vellum.capital/?ref=portfolio) since 2018. I built an institutional crypto-asset custody platform at CCSS Level 3: multi-signature cold storage, MPC, sub-one-hour disaster recovery, and end-to-end hedge-fund infrastructure on AWS. Custody at that level is an exercise in the same discipline the AI work runs on: blast radius, reversibility, and a named human on every irreversible action.

## Celsius: staying through the collapse

As Senior Engineering Manager (2022–2024) I directed 24 engineers across the US and Europe. We launched wrapped-token assets at over $100M TVL with Chainlink Proof-of-Reserve, and I drove the MetaMask Institutional integration.

Celsius filed for bankruptcy in July 2022, four months after I joined. I stayed two more years, and most of what this page claims comes from that period, because the wind-down was the engineering problem. The Fireblocks auditing tools I built scanned more than 5 million vaults across 20+ EVM networks to account for assets that had to be found before they could be returned, and recovered more than $4M that was stranded. That money belonged to creditors and would have stayed lost. Keeping custody infrastructure running, and making the books provable, inside a collapsed crypto firm is the least forgiving reliability environment I have worked in, and it is where the "irreversible actions get a named human" instinct stopped being a principle and became muscle memory.

## Royalty Exchange: payments and a world-first

As CTO (2020–2021) I ran the AWS migration on Django REST and React, automated Stripe and Plaid flows toward PCI-DSS readiness, and shipped a [world-first Ethereum NFT platform for music royalties](https://www.billboard.com/pro/royalty-exchange-adds-nft-auction-program/) with ASCAP and BMI.

## The through-line

Twenty years, and the same two instincts every time: the system of record wins, and irreversible actions get a named human. The AI platform work is where they point now. The fintech decade is where they came from.