Co-Founder & CTO, Sereel Blockchain infrastructure engineer
Fredrick Waihenya, Bunny
I've spent years building custody, tokenization, and settlement systems for institutions that move real assets onchain.
01 / Selected work
Selected work: What I build.
Most of my work comes down to four things: securing institutional funds, keeping systems interoperable, letting assets reach markets beyond where they were issued, and giving software agents a safe way to act.
Share certificate, London Stock Exchange, 1920. Compliant securities onchain
Issue digital securities to eligible investors. Keep transfers within the rules.
I build issuance and ownership systems that connect investor verification, transfer restrictions, and asset administration. My work covers the contracts, deployment, and compliance infrastructure behind them.
In operationCanton validator nodes and DAR deployments, run by me.
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The contracts enforce transfer rules, investor identity, and issuer controls themselves, so a security can change hands onchain and stay within its regulatory limits.
- ERC-3643 / T-REX
- Permissioned security tokens with transfer controls.
- CMTAT
- Compliant asset-token contract architecture.
- OnchainID
- Investor identity tied to token permissions.
- Canton / DAML
- Privacy-preserving securities and derivatives workflows.
- Canton validators
- Node setup and operation, plus DAR package deployment.
Bank vault. Institutional custody
Define who can move assets, which approvals they need, and how each action is recorded.
I build custody systems that separate key storage from transaction processing, require multiple approvals, and coordinate asset movements across networks. My work includes both active wallets and offline storage.
In operationMultisig wallet stack in production.
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The policy layer sits apart from signing, so approvals, limits, and audit trails hold on every chain a desk touches.
- Rust
- Multisig custody and transaction orchestration.
- Bitcoin / Monero
- Hot and cold wallets, key custody.
- EVM / Solana / IOTA
- Multichain wallet and transaction infrastructure.
- Canton
- Custody for institutional workflows.
Connected infrastructure. Private settlement for digital markets
Participate in lending and trading while protecting sensitive positions.
I connect lending, liquidity, and yield strategies to institutional settlement workflows. My work covers the financial contracts, transaction infrastructure, and private execution environment.
Supporting evidenceCo-author of an institutional DeFi protocol whitepaper.
Read the whitepaperDetailsClose
Execution on Prividium and DAML keeps positions confidential while the protocol integrations stay composable with the rest of DeFi.
- Canton / DAML
- Contracts for securities, derivatives, and structured products.
- ZKSync Prividium
- Private chain for confidential settlement.
- Uniswap / Aave / Morpho / Lido / Euler
- Protocol integrations and tokenized yield strategies.
- ERC-4626
- Vaults that hold the yield strategies.
Programmable action. Agentic wallets
AI agents that act with money inside the same policy a person would face; work in progress.
Orchestration for AI agents that hold wallets: intent-based execution, programmable money flows, and compliance checks before an agent can sign. Agent SSH, my open-source broker, is the shipped piece of that idea, applied to servers: credentials stay behind the broker, and every action is approved and logged.
Open sourceAgent SSH is public today; the wallet orchestration is in progress on the custody stack above.
Open Agent SSHDetailsClose
The agent gets a narrow, approved surface and full output back; keys and policy stay on the broker side, so an agent can act without ever holding the secret.
- Agent SSH
- Brokered SSH for AI agents: approvals, full command output, audit trail.
- Intent execution
- Agents express intents; the broker turns approved intents into transactions.
- Policy and compliance
- Spending limits and compliance checks run before signing.
- Multisig custody
- The same signing and audit layer used for institutional custody.
Protocol experience
Morpho- Variable-rate lending-market integrations and ERC-4626 vault strategies on EVM.
- Morpho Midnight
- Fixed-rate, fixed-maturity lending markets, with credit and debt units that settle at maturity.
02 / Networks
Networks: Where it runs.
- Standards
- ERC-3643, CMTAT, ERC-4626, OnchainID, DAML
- Languages
- Solidity, Rust, DAML, TypeScript
- BitcoinMultisig custody with hot and cold key separation
- EVMEthereum node operations, zkTLS oracles, orderbooks, CMTAT and T-REX tokenization, compliance
- CantonValidator nodes, DAR deployment, DAML securities and derivatives contracts, multisig custody
- SolanaMultisig custody in the Rust wallet stack, compliant tokenization
- StellarInstitutional settlement infrastructure, plus asset issuance
- IOTACompliant tokenization, multisig custody, transaction orchestration
- MoneroHot and cold wallet custody with segregated key storage
Protocols
Uniswap
Aave- Morpho
Lido
Euler
Kamino
Jupiter- Morpho Midnight
03 / Experience
Experience: Where I've worked.
Where I've done this work: custody, data infrastructure, and fintech engineering since 2021.
SereelCo-Founder & CTOSeptember 2024 - PresentDetailsClose
- Architect and deploy ERC-3643 (T-REX) and CMTAT compliant security token contracts with OnchainID identity management for compliance and KYC/AML requirements.
- Design and maintain Sereel's technical architecture, from blockchain infrastructure to backend microservices, API gateways, and user-facing systems.
- Engineer DAML smart contracts for securities, derivatives, and structured products on Canton DLT, enabling privacy-preserving institutional workflows.
- Set up and operate Sereel's Canton validator nodes and deploy DAR packages to the network.
- Deploy and operate ZKSync Prividium private chain infrastructure for confidential settlement and compliant DeFi execution.
- Build multisig custody infrastructure in Rust covering Bitcoin, EVM chains, Solana, IOTA, and Canton with secure key management and transaction orchestration.
- Engineer DeFi integrations with Uniswap, Aave, Morpho, Lido, and Euler, plus ERC-4626 vault contracts for tokenized yield strategies.
- Co-authored the Sereel Protocol whitepaper introducing a unified AMM, peer-to-peer lending, and options trading framework for institutional DeFi.
Riotous Play B.V.Lead Backend EngineerMarch 2024 - March 2025DetailsClose
- Built and maintained wallet infrastructure for Bitcoin and Monero, running hot and cold wallets with segregated key custody.
- Implemented provably fair game engines in Rust using verifiable randomness, ensuring transparent and auditable outcomes.
- Delivered 99.99% API uptime for a high-frequency gaming platform while actively defending against security threats and DDoS attacks.
- Designed deployment pipelines with zero-downtime releases, automated rollbacks, and comprehensive monitoring across production environments.
Earlier Engineering RolesBackend & Infrastructure Engineer2021 - 2024DetailsClose
- Crafted Systems: Architected data infrastructure and analytics pipelines supporting 20+ organizations with DBT, Airflow, Superset, ClickHouse, and PostgreSQL; built custom Rust-based PostgreSQL extensions and maintained highly available CloudNativePG clusters with 99.99% uptime.
- Hasibu: B2B backend systems serving 300+ businesses with microservices, Kafka event streaming, and automated CI/CD pipelines.
- Ohospital Inc.: Kubernetes cluster management on AWS, HIPAA-compliant infrastructure, and DevOps automation for telehealth platforms.
- Clickbanx: Core fintech API development, third-party payment integrations (M-Pesa, Flutterwave), and security architecture for Pan-African banking.
- Monzo Bank: Fraud detection systems and transaction monitoring infrastructure in London, contributing to real-time risk analysis pipelines.
- Node operations: Ran and maintained Ethereum nodes in earlier infrastructure work, ahead of the Canton validator operations at Sereel.
04 / Side projects
Side projects: Also built.
Two Rust tools I use: one written from scratch, one extended from upstream. Both open source.
Plate I · Open source · RustAgent SSHBrokered SSH for AI agents. Credentials stay behind the broker; every command returns full output with approvals and an audit trail.Open project
Plate II · Open source · Rust · forkRusty TelescopeA node exporter for machine metrics: memory, disk, and CPU. Built on Blockops Network's telescope-rust, with my changes on top.Open project05 / Writing
Writing: Notes.
Notes on tokenization standards, institutional privacy, and owning your own AI context.