Outside IR35 · UK Ltd · B2B

B2B Contracting
Outside IR35

Fixed-scope, milestone-based AI platform and infrastructure engagements. Work through UK Ltd — outside IR35 by design. No day rate — project-based pricing that aligns incentives to delivery.

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IR35 Status & Structure

Five key facts every procurement team needs. All contractually demonstrable.

Entity
UK Ltd company
B2B only — no PSC / umbrella ambiguity. Clean corporate structure.
IR35 Determination
Outside IR35
Fixed-scope deliverables, no substitution restriction, client does not control working practice. HMRC CEST determination available on request.
Engagement Type
Project-based milestones
Not time-and-materials. Scope locked at start. Deliverable + acceptance criteria defined before work begins.
Right of Substitution
Retained
Standard B2B substitution clause included in contract template. Genuine, not nominal.
Mutuality of Obligation
None
Project ends at deliverable acceptance. No implied continuation obligation on either party.

Engagement Types

Four structured engagement models — each with defined scope, duration, output, and exit. Click to expand.

AI Platform Build ▾
End-to-end delivery
4–12 weeks · deployed + documented
Full platform or defined subsystem — architecture through production deploy and handover.
Scope

Voice AI pipeline, messaging/agent platform, AKS cluster setup, multi-tenant SaaS infrastructure, or defined subsystem. Scope locked at project start with explicit acceptance criteria.

Outputs & Exit

Deployed, documented, operational system. Includes operations runbook, architecture diagram, component deep-dives, and a handover session for your team. You should be able to operate it without me after exit.

Architecture Review ▾
Review & Rescue
1–2 weeks · written report
Structured review of an existing AI/cloud system against reliability, cost, and security criteria.
Scope

Defined system or component. Reviewed against reliability, cost efficiency, security posture, and observability criteria.

Outputs & Exit

Written findings report + risk matrix + prioritised remediation roadmap. Presented to technical and exec stakeholders. Optional follow-on implementation sprint scoped separately.

Incident Response ▾
Production Stabilisation
Days to 2 weeks
Root-cause analysis, fix implementation, monitoring improvement, and post-mortem for a specific production failure class.
Scope

Specific incident or recurring failure class. Short-term embedded engagement to resolve the issue and prevent recurrence.

Outputs & Exit

Fix deployed + RCA documented + monitoring alert added + playbook written. Recurrence prevention built in, not bolted on.

Fractional Retainer ▾
Fractional Platform Engineering
3–6 months · monthly deliverables
Ongoing B2B advisory + implementation for early-stage teams building AI infrastructure. Not day-rate — deliverable commitments defined monthly.
Scope

Monthly defined deliverables — shipped features, architecture decisions, technical steering. Scope agreed at the start of each month.

Outputs & Exit

Shipped features + architectural steering documentation. Exit includes team handover sprint and documentation package so the team can continue without dependency on me.

What Every Engagement Includes

Production-ready delivery

Code deployed to AKS/cloud with health checks, monitoring, and runbooks. Not prototype handoffs.

Architecture decisions documented

Every significant decision written with context, alternatives, and trade-off rationale. Future maintainers inherit reasoning, not just code.

Failure modes anticipated

Circuit breakers, retry logic, graceful degradation, and documented failure scenarios for each integration point.

Clean handover

Operations runbook, architecture diagram, component deep-dives, and a handover session. You should be able to operate it without me.

Common Screening Questions

Can you provide a SDS (Status Determination Statement)?
Yes. My Ltd company operates on fixed-scope deliverable contracts that satisfy the three primary IR35 tests: no control over working practices, genuine right of substitution, and no mutuality of obligation beyond the contracted deliverable. I can provide a completed HMRC CEST determination and contractual documentation on request.
Are you open to onsite work?
Short-term onsite for specific milestones — architecture review sessions, handover, stakeholder presentations — yes. Sustained day-to-day onsite is not compatible with an outside-IR35 B2B structure and I decline those arrangements.
What is your notice / availability?
Typically 2–4 weeks lead time for a new project start. Current availability is best confirmed by contacting directly. No rolling contract to exit — current engagements always have a defined end date.
Do you work through agencies?
I prefer direct B2B. Agencies introduce IR35 complexity — most add PAYE/umbrella requirements that change the engagement structure. For larger organisations with procurement requirements, I can work through a narrow set of agency arrangements that maintain outside-IR35 status. Contact to discuss.
What is your rate?
Project-based pricing rather than a day rate. Scope, deliverables, and acceptance criteria defined before pricing. This aligns my incentive to delivered outcomes, not billed hours. Contact to discuss scope and I will provide a fixed-price proposal within 48 hours.
What tech stack can you work with?
Primary stack: Python (FastAPI), Azure (AKS/K8s), Redis, Firestore, GitHub Actions. AI integrations: Groq, Deepgram, Azure TTS, Twilio, WAHA. Secondary: GCP, AWS, Node.js, TypeScript/React. I can also adapt to your existing stack for architecture review and rescue engagements.

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