● Fractional CTO · Chicago market, remote across US time zones
SeanSteinhoff— Fractional CTO & Advisory
Fractional CTO & product-technology advisory — architecture, delivery, and technical leadership for SaaS and data-heavy businesses.
15+ years across full-stack platforms, systems integration, and automation in regulated industries. Founder & CEO of ANUP Technologies. Available for a limited number of outside engagements.
02 — What I do
Four engagements, one operating standard.
I work with founders, operators, and acquisition investors — search funds, independent sponsors, and holdcos evaluating or integrating technology businesses.
Fractional CTO
“Two Days a Week”
Ongoing, embedded, accountable technical leadership. Architecture ownership, senior-hire vetting, build-vs-buy, vendor decisions, engineering process. Monthly retainer. For funded companies hiring engineers with no one to run them.
90-Day Platform Reset
Fixed-scope: audit the current system (architecture, security posture, data integrity, delivery pipeline), findings in week 3, hands-on execution of the top-priority fixes through day 90. Fixed fee. For platforms that grew faster than their foundations.
Technical Diligence Read
1–2 week fixed-scope assessment for acquirers, investors, or boards: codebase health, architecture risk, security patterns, key-person dependency. Honest verdicts with evidence pointers. Fixed fee.
Post-Acquisition Technical Remediation
For new owners who inherited a system with no documentation, a departed founder-developer, and no internal engineers to assess it. Scoped engagement to document the platform, stand up delivery and security practices, resolve critical risks, and hand over something an operating team can run. Fixed fee.
Contact for pricing.
03 — Selected work
Shipped systems, not slideware.
Featured
[PRODUCTION]ANUP Technologies · Founder & CEO (2024–present)
Conceived and solo-architected a multi-tenant compliance automation platform for the clean-energy market: ~185,000 lines of TypeScript, 145 serverless edge functions, 325 database migrations — one author, real paying tenants.
- 11 hardware-vendor API integrations across five distinct auth schemes (OAuth2, session-token, static-key, HMAC-SHA1/256), normalized into one canonical data model
- Cryptographic provenance layer — Merkle custody chains with atomic, crash-safe sealing; tens of thousands of records sealed, zero chain breaks
- Row-level tenant isolation on 100% of tables behind a tiered, individually-verified security remediation program
- Deployed across portfolios spanning 60+ solar installations; 40+ sites under active management
- July 2026: first fully autonomous quarterly billing cycle — generated, verified against physical meters to the hundredth of a kWh, delivered end to end with zero human intervention
Founder / Architecture / Regulated data / Solo-built
Multi-Tenant ETL & Data Integration Console · Contract engagement
Designed and built for an international client: a data-pipeline platform for teams moving data between operational systems without bespoke integration code — connector configuration, schema discovery, visual pipeline design, and an AI copilot in one console. (Client-owned system.)
- ~50 hot-swappable source adapters (Postgres, Snowflake, BigQuery, Salesforce, Kafka, S3, GA4…) resolved dynamically through a pluggable adapter SDK — connector-specific config forms rendered from the spec
- Envelope-encryption KMS on versioned key-encryption keys with multi-key decrypt rotation — secrets never leave the edge in plaintext
- Multi-provider AI layer normalizing OpenAI / Anthropic / Gemini behind one proxy, including an AI control surface performing real tenant-scoped platform mutations
- Visual pipeline canvas (typed nodes, palette, graph persistence)
Data infrastructure / Security / AI systems
PitchSlap (CAPRUX Studio)
A multi-agent AI copilot walking early-stage founders from rough idea to investor-ready pitch — five specialized agents that draft, critique, fact-check, and package.
- Per-agent edge-function architecture: isolated keys, model selectors, and functions per AI persona — rate isolation, billing separation, per-agent analytics
- Streaming completions read incrementally client-side; prompt hashing and duration logging server-side
- Cross-origin OAuth broker: session minted on a central auth domain, rehydrated on tenant subdomains, preserving route and form state through the round trip
- Token-metered plan economy enforced in SECURITY DEFINER SQL — paywall logic server-side, never in the client
- RAG prompt enrichment via Postgres RPC — prompt engineering as configuration, swappable without redeploys
LLM engineering / Multi-agent / Auth architecture
RT46 Fleet Management Platform · Contract
Assessment-then-execution engagement on a government-focused fleet-oversight platform serving a distributed international team: evaluated a large legacy React codebase, then executed the stabilization — design-system alignment, component refactoring, API integration hardening.
Technical assessment / Legacy modernization / Distributed team
The Lab — a product studio where I pressure-test architecture patterns. All built solo on a shared multi-tenant platform: namespaced schemas, tenant-scoped RLS, token economies in server-side SQL, streaming AI.
- 01ContractPatch — clause-level contract risk scoring with AI redlines and a token economy, on tenant-scoped RLS with branded transactional email resolved per tenant
- 02VisadoCoach — tiered AI interview-prep for consular applicants; progressive-disclosure intake, tier-gating encoded in the design system
- 03OffboardMe — an exit-assistant guiding goodbye letters and closure checklists; fully tokenized HSL design system, per-user isolated storage
- 04CustodyMap — court-defensible documentation for parents in custody disputes; plan-tier gating enforced in SECURITY DEFINER SQL
- 05CAPRUX.com — the studio's front door: table-driven streaming AI assistant with persona hydration from Postgres, R3F 3D UI
04 — How I work
Five principles I don't compromise on.
- / 01
Outcomes over hours.
Every engagement starts with what “done” means, in writing.
- / 02
Verify, then assert.
I check production, not reports. Claims come with evidence.
- / 03
Paper everything.
Decisions, scope, and changes live in documents, not memories.
- / 04
Small blast radius.
Sequenced changes, smoke-checked deploys, no heroics in prod.
- / 05
Honest no's.
If something shouldn't be built, I'll say so before you pay for it.
I run an AI-augmented build/verify discipline: AI drafts code, migrations, and diagnoses at small-team throughput; an independent verification pass re-checks every finding against the live system; and nothing touches production without explicit human sign-off, per action. The result is velocity close to a team's with a review gate most teams don't have — and it's a process your company keeps after I leave.
05 — Background
Fifteen years of shipping.
Fifteen years across engineering and product leadership: B2B SaaS operations direction, creative and marketing technology, and — since 2024 — founding and running a compliance automation company in the clean-energy space. I've been the director, the architect, the sole engineer, and the CEO; the useful part is knowing which hat a given problem actually needs.
Based in the Chicago market, working remotely across US time zones. Bilingual English/Spanish.
Credentials
- React
- TypeScript
- Postgres/Supabase
- Node
- Python
- Multi-tenant SaaS
- API/OEM integration
- Stripe billing
- Regulated-data pipelines
- CI/CD
06 — Contact
Currently taking a limited number of engagements.
Email is fastest: hello@seansteinhoff.com. Tell me what you're building, what's broken, or what you're deciding — I'll reply within one business day.
Engagements are scoped to avoid any conflict with my obligations as CEO of ANUP Technologies.