On-chain engineering
Contracts and oracle plumbing that pass institutional-grade review.
- Chainlink CRE / oracle integration ⭐
- Solidity dev + adversarial security audit
- DeFi treasury & capital automation
- CCIP cross-chain flows
Autonomous on-chain + AI systems
One builder — from the smart contract to the pixel.
I design, build, audit, deploy, and operate autonomous on-chain + AI systems end-to-end — Chainlink / oracle integration, Solidity contracts, quant strategy, AI-agent orchestration, and 24/7 production ops — and I build the verification machinery that keeps them honest.
Systems engineer + creative technologist · Remote, Mallorca · invoiced in USD/USDC
$ git log --author="Sebastian Hein" --stat
148,000 lines of code · solo
950 commits · 94 active days · 8 months
12+ Solidity contracts · Arbitrum One
7 Chainlink CRE workflows · on-DON
100+ AI-agent modules · Groq / Anthropic
live Hyperliquid perps · fail-closed
✔ verified on-chain · no return %s quoted
What I build
Three disciplines most teams hire three people for.
The rare part isn't any one piece — it's that all of it lives in one person, held to a verification culture strict enough that I built the audit which caught my own overfit.
Autonomous AI + quant
Systems that run themselves — and prove they should before they touch capital.
- Multi-agent LLM orchestration (100+ modules)
- Algo-trading on Hyperliquid perps
- Walk-forward OOS + Deflated-Sharpe validation ⭐
- Edge SRE on a Raspberry Pi production stack
Design / creative tech
I make systems that look like something — 15 years in light & live production behind it.
- 3D WebGL data-art & live dashboards
- Blender cinematics of the data model
- Custom design systems
- The top-of-range justifier, never a cheaper add-on
The system · capitalMagic
A ~148K-LOC autonomous system, one operator.
Data flows one way, every stage is gated, and every layer is one I designed, built, and operate solo.
flow → execution · on-chain · consensus · intelligence · ops · verification
01 / EXECUTIONHyperliquid perpsAutomated perps bots with exchange-side stops + isolated sub-account margin firewalls.
02 / ON-CHAINArbitrum contracts12+ Solidity contracts — DCA, waterfall, tax, oracle, CCIP.
03 / CONSENSUSChainlink CRE7 on-DON workflows, TypeScript→WASM, median consensus.
04 / INTELLIGENCEAI-agent layer100+ modules, cost-tiered LLM routing, guardian audits.
05 / OPSRaspberry Pi 5systemd + git-CD, fail-closed deploys, Tailscale-only edge stack.
06 / VERIFYValidation harnessWalk-forward OOS + Deflated Sharpe gate every change.
Proof · the receipts
Rigor you can inspect.
"I built the statistical audit that caught my own over-optimistic backtest — then shipped the fixes."
Walk-forward OOSDeflated Sharpe · Bailey & López de Prado 201452 / 78-agent audits · 0 crit/highFail-closed deployVerify-on-chain ruleBacktest P&L = simulation projections, not returns
NetworkArbitrum One · 42161
Contracts live12+
Solidity0.8.20 · OpenZeppelin v5
Security audits52 / 78-agent · 0 crit/high
CRE workflows7 · on-DON
Claim policyon-chain before stated
Work with me
One builder replaces a small team.
Fixed-scope engagements so you can say yes fast. Remote, worldwide — invoiced in USD/USDC.
CRE / Chainlink Integration Sprint
from $30k fixed
Data Feeds + CCIP + on-DON automation, wired, hardened, and reviewed.
Contract + Adversarial Audit
from $15k fixed
Solidity authorship plus a multi-agent adversarial security review.
Perps Automation & Risk Layer
from $30k + retainer
Exchange-side risk, sub-account firewalls, and on-chain execution for HIP-3 teams.
Also: fractional-CTO · smart-contract security · quant validation · AI multi-agent automation · creative-tech data-viz.
Contact
Wiring up Chainlink CRE, hardening a contract, or need a solo team for a DeFi build?
I take on a small number of engagements. Tell me what you're shipping — I'll send a receipt, not a pitch.