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AI Architecture Consulting

AI architecture consulting for LLM and agentic systems

Senior architects design and review the architecture behind AI products - model strategy, retrieval, orchestration, evaluation and cost - and stay to help build it.

For product and engineering teams building LLM, RAG or agentic systems.

  • Architecture-first
  • Vendor-neutral
  • Practitioners who build

Powered by Comtau Inc.

  1. Product & UX
  2. Orchestration & agents
  3. Retrieval & RAG
  4. Model gateway
  5. Data & pipelines
  6. Platform
  • Evaluation & guardrails
  • Observability & cost
  • Security & governance
Six layers, three rails, one accountable architecture. The full reference is below.

Where AI prototypes break

Demos are easy. Production is where the architecture shows

Most AI products don’t fail because the model is wrong. They fail because nobody designed the system around it.

  1. Model and vendor lock-in

    Architecture decisions get made implicitly, by whichever API was fastest to integrate first.

    Swapping providers later means rewriting half the system.

    Fixed at04 Model gateway

  2. Retrieval that degrades quietly

    RAG pipelines are tuned once at launch and never revisited as data grows.

    Answer quality drifts down and nobody notices until a customer does.

    Fixed at03 Retrieval & RAG

  3. No way to measure quality

    There is no evaluation process, so nobody can say if a change made things better.

    Every release is a guess dressed up as a deploy.

    Fixed atEvaluation rail

  4. Inference cost outrunning the business case

    Cost was never designed in, only discovered on the first real invoice.

    Usage growth starts to look like a threat instead of a win.

    Fixed atObservability & cost rail

  5. AI-generated code nobody fully owns

    Code lands faster than anyone can review or understand it.

    Technical debt accumulates faster than the team can see it.

    Fixed atArchitecture decision records

  6. Safety and governance bolted on late

    Guardrails get added after an incident, not designed in from the start.

    A single bad output becomes a company-wide fire drill.

    Fixed atSecurity & governance rail

Reference AI system architecture

What we design and review, layer by layer

An AI system is a set of architecture decisions, not one model call. Each layer below is a decision Comtau makes explicit and documents.

BuildBuyConfigure
  1. Product & UX

    • AI features & UI(Build)
    • Human-in-the-loop review(Build)
    • Feedback capture(Build)
    Decision we make explicit
    Where AI sits in the workflow, what the user sees when it is wrong, and where a human approves.
    Artefact
    Interaction and fallback design
  2. Orchestration & agents

    • Agent / workflow runtime(Configure)
    • Tools & function calls(Build)
    • Memory & state(Configure)
    • Prompt management(Configure)
    Decision we make explicit
    How agents, tools, memory and human-in-the-loop steps are composed.
    Artefact
    Orchestration design · Tool & agent boundaries
  3. Retrieval & RAG

    • Chunking & embeddings(Configure)
    • Vector / hybrid search(Buy)
    • Re-ranking(Configure)
    Decision we make explicit
    How context is found, ranked and handed to the model for each request.
    Artefact
    Retrieval architecture
  4. Model gateway

    • Hosted models(Buy)
    • Open-weight models(Configure)
    • Routing & fallback(Build)
    Decision we make explicit
    Which models and providers the system relies on, and how it fails over.
    Artefact
    Model selection criteria · Vendor & fallback strategy
  5. Data & pipelines

    • Sources & ingestion(Build)
    • Pipelines & refresh(Build)
    • Access & lineage(Configure)
    Decision we make explicit
    How data is ingested, embedded, stored and kept current.
    Artefact
    Data pipeline design
  6. Platform

    • Cloud & hosting(Buy)
    • Auth & tenancy(Configure)
    • Deployment & CI(Configure)
    Decision we make explicit
    Where the system runs, how tenants are isolated, and how changes ship safely.
    Artefact
    Deployment and platform design

Across every layer

  • Evaluation & guardrails

    How output quality and safety are measured and enforced before release.

    Artefact: Evaluation plan · Guardrail design

  • Observability & cost

    How the system is monitored in production and kept inside budget.

    Artefact: Observability plan · Cost model

  • Security & governance

    Access control, data handling and compliance across the AI stack.

    Artefact: Security review · Governance framework

Generic reference architecture, not a client system. Build / buy / configure markers show a typical starting point; each one is decided per system.

When teams bring us in

Common questions that turn into an engagement

  • “We’re evaluating three model vendors and can’t tell which one actually fits.”

    A vendor and model strategy tied to your data, cost and latency constraints.

  • “Our RAG quality plateaued and we don’t know why.”

    A retrieval architecture review, from ingestion to ranking.

  • “The agent prototype works in a demo. We need it to work in production.”

    A production-grade design: orchestration, evaluation, guardrails, cost.

  • “We’re adding AI to an existing platform and don’t want to re-architect everything.”

    An integration design that respects what already works.

Engagement types

Review, design, or hands-on build

The three connect: a review can lead to a design, and a design can carry straight into implementation with the same team.

  1. 01 · Assess

    Architecture Review

    You have an AI system or a plan for one, and need an independent view of it.

    An independent review of an existing or planned AI system architecture, with findings and prioritised recommendations.

    • Current-state assessment
    • Risk list
  2. 02 · Design

    Architecture Design

    You know what the product must do and need the system designed before it is built.

    A target reference architecture and the decisions behind it - model strategy, data, orchestration, evaluation and cost - recorded as ADRs your team can build from.

    • Reference architecture
    • Architecture decision records
  3. 03 · Execute

    Implementation Guidance

    The design is agreed and you want the people who made it involved in the build.

    Hands-on support carrying the design into a working system, through Comtau’s own build process.

    • Implementation roadmap
    • Build handoff

Looking for a review of a non-AI system? See Software Architecture Review

Building on AI you can’t yet explain?

Tell us what the system needs to do. We’ll show you the architecture decisions that matter before you build the wrong thing twice.

Book a call

Direct conversation with a senior CTO/architect. We’ll review your situation and determine the useful next step.

How we work

Assess. Design. Execute.

Every stage leaves an artefact your team keeps, whether or not Comtau builds the system.

  1. Assess

    Understand the current prototype or system, the data available, and what actually constrains it.

  2. Design

    Decide the target architecture layer by layer, and record why.

  3. Execute

    Carry the design into a working system, hands-on, or hand it to your team to build.

Architecture you can read, not just a diagram

Every design ends in documents your team keeps. The decision record is the core of it: one per significant decision, tied to a layer of the architecture.

  • Reference architecture

    The layered target system, with components and boundaries.

  • Architecture decision records

    One record per significant decision, with options and consequences.

  • Evaluation plan

    How quality and safety are measured before each release.

  • Roadmap

    The order in which the architecture is built or changed.

  • Risk list

    What could break, where, and what reduces it.

Architecture Decision Record

Illustrative format · not client material

ADR-0XX · Route requests through a model gateway with provider fallback

Accepted
Layer
04 Model gateway
Rails touched
Evaluation · Cost
Owner
Architect of record

Context

Why the decision is needed now: the constraint, the requirement, what breaks if nothing changes.

Options

  • ASingle provider, called directly
  • BGateway with routing and fallback
  • CSelf-hosted open-weight model

Decision

The chosen option and the reasoning, in terms of your data, cost and latency constraints.

Consequences

  • gainWhat becomes easier
  • costWhat becomes harder or must be maintained

Evaluation gate

The check that must pass before the change ships.

Architecture Decision Record: ADR-0XX · Route requests through a model gateway with provider fallback. Illustrative format · not client material
  • Architecture-first: decisions are made and documented before code, not discovered after an incident.
  • Practitioners who build: the people who design the architecture can also implement it.
  • Vendor-neutral: recommendations follow your constraints, not a partnership with a model provider.

From operating experience

We build with AI agents ourselves, under explicit controls

Comtau builds its own software with AI coding agents inside its own system for planning, running and verifying the work. The controls that make that safe are the same ones a production AI system needs, so we design them from practice, not from a vendor diagram.

Bounded scope
Inside ComtauEvery agent task states what it may change and what is out of bounds.
In your systemAgents and tools get explicit permissions and boundaries, not open-ended access.
Stop and escalate
Inside ComtauWork stops on a failed check, scope growth or a missing approval, and a person decides.
In your systemEscalation paths to a person are designed in for the cases the system should not decide alone.
Traceable runs
Inside ComtauEach run records the prompt it was given, the model used, an event trail and its token and cost figures.
In your systemEvery AI action is traceable: inputs, model version, tool calls and cost.
Verification separate from generation
Inside ComtauOutput is checked by tests and by independent read-only reviewers, never signed off by the agent that produced it.
In your systemEvaluation and guardrails sit outside the component that generates the output.
Human-owned irreversible actions
Inside ComtauArchitecture changes, new dependencies and releases need explicit human approval.
In your systemActions that cannot be undone sit behind an approval step, by design.

This describes how Comtau engineers its own software. It is not a product we sell; it is the operating experience behind the architecture work.

A short note on roles and cost

AI architect, AI engineer, or ML engineer?

AI architect
Decides the system’s structure: which models, how data flows, how quality is evaluated, and where the risk sits.
AI engineer
Builds the product inside that structure: orchestration, retrieval, integrations.
ML engineer
Builds, trains and tunes the models and the pipelines around them.

Comtau does both - the architecture and, where useful, the build.

Cost follows scope, not a rate card

What drives the scope

  1. How many layers need a decision
  2. How deep the review goes
  3. Whether the engagement ends at a design or carries into implementation

Related

FAQ

AI architecture consulting questions

What does AI architecture consulting include?

Model and vendor strategy, retrieval and data architecture, agent orchestration, evaluation and guardrails, observability, and security and cost. Each area is a decision we make explicit and document, not a checkbox.

Do you only review, or do you also design and build?

Both. A review can stand alone, or it can lead into a target architecture and, from there, hands-on implementation with the same team - assess, design, execute.

How is this different from AI Production Readiness?

This page is for designing or reviewing an architecture. If you already have an AI MVP and want it audited and hardened for production, see AI Production Readiness.

Are you tied to a particular model or vendor?

No. Recommendations follow your data, cost and latency constraints, not a partnership with a model provider. Vendor and model choices are treated as an architecture decision, not a default.

Who owns the architecture and documentation afterwards?

You do. Architecture decision records, the reference architecture and the roadmap are written to be used by your team, with or without Comtau continuing.

What does an engagement cost?

Cost follows scope: how many layers need a decision, how deep the review goes, and whether the engagement ends at a design or carries into implementation. There is no fixed rate card - each engagement is scoped individually.

How is this different from general software architecture consulting?

AI systems add decisions that traditional architecture work doesn’t cover: model behaviour, retrieval quality, evaluation and inference cost. For architecture work without those AI-specific concerns, see Software Architecture Consulting.

Design the AI architecture once, properly

Tell us what you’re building. We’ll help you work out whether you need a review, a design, or hands-on implementation - and what that would produce.

Direct conversation with a senior CTO/architect. We’ll review your situation and determine the useful next step.

What happens next

  1. 01You describe the system and where it’s stuck
  2. 02We identify the architecture decisions that matter most
  3. 03We define the useful next engagement