Services / Fractional AI Architect
Fractional AI Architect for Startups: Part-Time CTO-Level Guidance Without Full-Time Cost
Reserve 20-40 hours per month of senior engineering to design RAG systems, MCP integrations, and security-hardened platforms. You get architecture, code, and penetration testing from the same engineer who has shipped production systems for 15 years.
I stay independent on purpose—as a solo AI consultant who leads as an architect, you work directly with the person advising investors and writing the code. Perfect for pre-seed to Series A startups that need a CTO-level partner but don't want to hire full-time or juggle an agency team.
Who this is for
- Founders who need a senior engineer to own RAG/agent architecture while the team ships product.
- Teams preparing for enterprise diligence (SOC 2, security questionnaires) and needing guardrails baked in.
- Startups running AI pilots that must become reliable features with observability, incident response, and cost controls.
- Companies modernizing from Rails/Drupal/WordPress to a Next.js + Supabase/Neon stack with AI features.
Outcomes we target
- A hardened RAG + MCP architecture with tenant-safe retrieval, eval harnesses, and kill-switches.
- Shipping agent-powered features that pass pen tests and have clear runbooks for incidents.
- Documentation packets investors and customers can trust (architecture, controls, testing evidence).
- Engineering velocity with a repeatable cadence: plan, build, test, secure—every month.
Why choose fractional instead of hiring or contracting?
Fractional gives you executive-level ownership with the flexibility of a retainer. You gain architectural depth, production security, and delivery velocity without onboarding a full team or training a junior hire on the job.
Hands-on CTO leverage
Architecture decisions map to implementation. I author RFCs, write production code, review pull requests, and run QA so strategy and execution stay aligned.
Security baked in
Every sprint includes penetration testing, prompt-injection defense, and governance artifacts for investor diligence. No last-minute audits.
Predictable cost
Monthly retainers are scoped to the hours you need (typically 20-40). No recruiting fees, no agency multipliers, and no unexpected staffing changes.
What you get every month
A repeatable cadence across architecture, development, and security so the platform moves forward every week.
Architecture & planning
- RAG/MCP architecture docs with context budgets and eval plans
- Backlog prioritization aligned to fundraising or launch goals
- Vendor/tool selection with cost modeling
- Weekly working sessions and async Loom recaps
Implementation & security
- Hands-on Next.js/Supabase development using Cursor + Claude
- CI/CD wiring with Playwright + Semgrep coverage
- Penetration testing + prompt-injection suites before release
- Documentation + handoff artifacts for investors or auditors
Engagement packages
Pick a retainer size that fits your runway. All packages include architecture + implementation + security.
Starter (20 hrs/mo)
Architecture + safety net
- Architecture docs for 1-2 features (RAG/agent flows).
- Security review + pen-test checklists.
- Weekly working session + async reviews.
Core (30 hrs/mo)
Plan + build + test
- Hands-on implementation for RAG/agents/Next.js features.
- CI/CD with evals + prompt-injection suites.
- Monthly status packet for investors/customers.
Scale (40 hrs/mo)
Ship & harden faster
- Parallel streams (feature build + security + observability).
- Playwright + Semgrep + adversarial suites embedded.
- Architecture oversight for contractors or internal team.
Engagement cadence
Each month follows a consistent rhythm so the team knows what to expect.
Step 1
Plan & align
We define goals, staffing constraints, and risk areas for the month. Architecture docs and acceptance criteria get drafted up front.
Step 2
Ship & review
I build features, run security tests, and review team contributions. Weekly calls keep stakeholders aligned and unblock decisions.
Step 3
Audit & document
Each month ends with a status packet: shipped features, security posture, risks, and next steps. Ideal for investor updates or diligence packets.
Security, compliance, and observability
- Penetration testing tailored to AI surfaces (RAG, MCP tools, prompt injection, tenant leaks).
- RLS-first data models and tenant assertions across APIs, agents, and vector stores.
- Observability with tenant-tagged logs, traces, and replayable agent/tool calls.
- Incident playbooks for hallucinations, poisoning, cross-tenant retrieval, and runaway costs.
- Evidence packs for SOC 2-style diligence (controls, test results, architecture diagrams).
Tooling & stack I standardize
- Next.js + Vercel + Supabase/Neon/Postgres for app + data.
- Clerk/Auth0 for auth; Stripe/Paddle for billing; PostHog/Sentry for telemetry.
- pgvector/Qdrant for RAG; hybrid search (BM25 + embeddings); rerankers where needed.
- MCP servers for safe tool exposure; LangChain/LangGraph or direct OpenAI/Anthropic APIs.
- CI/CD with Playwright, Semgrep, adversarial prompt suites, and cost budgets.
Example outcomes (anonymized)
A few representative engagements that show the mix of architecture, build, and security work.
Fintech SaaS
Multi-tenant RAG copilots
- Hybrid retrieval with tenant filters + rerankers.
- Pen-test findings reduced to zero criticals pre-launch.
- Eval harness improved answer accuracy by 19%.
Developer platform
Agent + MCP safety
- Tool registry with RBAC + per-tenant sandboxes.
- Observability traces for every agent/tool call.
- Cost caps and kill-switches for runaway loops.
Healthtech
Compliance-ready AI features
- PII/PHI redaction pre-embedding; audit trails end-to-end.
- Playwright + Semgrep + adversarial prompts wired into CI.
- Investor-ready packet with diagrams, controls, and test evidence.
FAQ
Honest answers before you bring on a fractional architect.
What is a fractional AI architect engagement?
It’s a part-time retainer where I act as your CTO-level architect 20-40 hours per month. I design RAG/MCP architectures, write code, run security reviews, and guide your roadmap without the cost of a full-time hire.
How long is the commitment?
Most retainers run 3-6 months with the option to extend. That window gives us enough time to architect, implement, and harden core features before handing off or planning the next phase.
Do you also handle development work?
Yes. I stay hands-on with Next.js, Supabase/Neon, Clerk, Stripe, LangChain, MCP servers, and security tooling. Architecture guidance comes with implementation, code review, and QA—not just slide decks.
Can we pause or scale hours?
You reserve a monthly block (20-40 hours). We can scale up or down with notice, but I cap active retainers to keep delivery predictable. If you need ad-hoc help later, we can convert to an advisory retainer.
Does this replace a security vendor?
Fractional work includes ongoing security reviews and prompt-injection testing, but I also offer standalone penetration tests if you need formal reports. Many teams combine both.
Ready to reserve fractional architect time?
Book a quick consultation to review your roadmap, security requirements, and timeline. If it's a fit, we pick a start date and block the hours.
For deeper dives, see our complete guides on penetration testing, RAG architecture, and AI agent architecture.
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