AI Product & Application Development Services

We build AI applications and products end to end, and add AI features to software you already ship — model selection, evaluation, cost and latency engineering, multi-tenancy, and the unglamorous production work that decides whether an AI feature survives contact with real users.

Where This Starts

The gap between a demo and a product that holds

Most AI products do not fail at the model. They fail at everything around it.

The prototype impressed everyone and then stalled

It works on the examples it was built against. Nobody knows what it does on the next thousand, and there is no way to find out safely.

Quality moves and nobody can tell why

A prompt gets tweaked, a model version changes, and output quality shifts. With no evaluation set, every change is a gamble.

The unit economics do not survive scale

Per-request cost was irrelevant in the demo. At real volume the feature costs more to run than the plan it ships on.

It is too slow to sit in the workflow

Latency that feels acceptable in a test feels broken inside a product where someone is waiting on the result.

One customer's data can reach another

Multi-tenancy was assumed rather than designed, and the first enterprise security review finds it.

You are locked into one provider

The system is written against one vendor's API surface, so pricing changes and deprecations are not decisions you get to make.

What We Build

Where teams bring us in

Three distinct engagements, and it is worth being clear which one you are actually in.

A new AI product from scratch

The AI capability is the reason the product exists. We build the whole thing — interface, backend, data layer, and the AI system inside it.

  • MVP to first customers
  • Evaluation from day one
  • Billing and accounts when needed

AI features inside an existing product

You have a product with users. The work is adding capability without destabilising what already ships.

  • Search and retrieval features
  • Drafting and summarisation
  • Extraction and classification

Prototype to production

Something already works in a notebook or demo. The remaining work is everything that makes it dependable.

  • Evaluation harness
  • Cost and latency engineering
  • Monitoring and rollback
Honest Answer First

When to build this, and when not to

AI features are expensive to run and to keep correct. That cost is worth paying for some problems and not others.

Worth building when

  • The task genuinely requires interpreting unstructured input
  • Users are already doing it manually at meaningful volume
  • An imperfect answer with review still beats the status quo
  • You can define what a good output looks like well enough to test it
  • The value per request comfortably exceeds the cost per request

Reconsider when

  • A deterministic rule or query would solve it more reliably
  • The output must be exactly right every time with no review path
  • Nobody can articulate what a correct answer looks like
  • It is being added because competitors have an AI feature
  • The per-request cost exceeds what the tier can support
Under The Hood

The parts that decide whether it survives

The model is a swappable component. These layers are what make the product dependable.

Evaluation harness

A versioned set of real cases with expected outputs, run before every change, so quality shifts are caught in CI rather than reported by customers.

Model routing & abstraction

Provider access sits behind an interface, so models can be swapped or mixed per task — and a pricing change or deprecation is a config decision, not a rewrite.

Cost & latency engineering

Routing simple work to smaller models, caching what repeats, streaming where waiting is visible, and keeping context tight because context is the bill.

Tenant isolation

Data separation, per-tenant configuration, and usage metering designed in, so the first enterprise security review is not a re-architecture.

Observability & tracing

Per-request traces covering prompt, retrieval, tokens, latency, and cost, so a quality complaint can be reproduced rather than debated.

Graceful degradation

Defined behaviour when a provider is down, rate-limited, or slow — the product stays usable rather than failing at the AI-shaped hole in the middle.

Scoping

What actually moves the estimate

Feature lists are a poor predictor of AI product cost. These factors matter considerably more.

How well 'correct' can be defined
If good output is easy to specify, evaluation is cheap and iteration is fast. If quality is subjective, expect substantially more cycles to reach something shippable.
Accuracy bar and review path
A feature where a human reviews output is far cheaper than one that must be right unattended. The absence of a review path is the expensive requirement.
Volume and unit economics
Expected request volume and context size drive both running cost and how much engineering goes into caching, routing, and model selection.
Latency requirements
Sub-second interactive responses constrain model choice and architecture much harder than a workflow that can take thirty seconds.
Multi-tenancy and compliance
Tenant isolation, audit logging, data residency, and SOC 2 readiness are design-time work, not features added at the end.
Existing codebase condition
Adding to a well-factored product with tests is straightforward. Adding to a system without either means the first work is making change safe.

The scoping session exists to answer this for your case. It produces a written scope, an architecture direction, and a cost range you can take elsewhere.

How We Work

From scoping to something users depend on

Step 01

Scoping session

We pressure-test the use case, define what good output looks like, and check the unit economics before anyone writes code.

Step 02

Evaluation before build

A test set of real cases comes first, so quality is measurable from the first commit rather than assessed by impression.

Step 03

Build in increments

Two-week cycles with working software, instrumented for cost and latency from the start rather than optimised afterwards.

Step 04

Production and handover

Monitoring, runbooks, and rollback paths, plus documentation for the team that maintains it — including if that team is not us.

Engineering

What we build with

Defaults, not constraints. Model providers in particular sit behind an abstraction so the choice stays reversible.

Next.js
React.js
TypeScript
Python
FastAPI
OpenAI
Claude
PostgreSQL
Supabase
Stripe
AWS
Docker
FAQ

Questions buyers actually ask

That is a large share of what we do. The work is adding capability without destabilising software that already has users — which means understanding the existing codebase, adding evaluation for the new behaviour, and shipping behind flags so it can be rolled back. It is usually a better first step than building a separate AI product alongside your main one.
Further than it looks, and the gap is rarely the model. What is typically missing: an evaluation set so changes can be made safely, cost and latency engineering for real volume, error handling for provider outages and rate limits, tenant isolation if it is multi-customer, and tracing so failures are diagnosable. That work is usually the majority of the remaining effort.
By treating cost as an architectural requirement rather than a bill you discover. That means routing simple steps to smaller models, caching repeated work, keeping context tight because context is most of the cost, and instrumenting per-request cost from the first build so you can see the trend before it becomes a problem. We model expected monthly cost during scoping.
No, and that is deliberate. Provider access sits behind an abstraction, so models can be swapped per task or replaced entirely when pricing, capability, or availability changes. Different steps in the same product often use different providers. The evaluation set makes switching a measurable decision rather than a leap.
An evaluation set of real cases with expected outputs, versioned alongside the code and run before every change. Without it, prompt and model changes are untestable and teams end up afraid to touch anything. We build it early because it is what makes iteration possible, not because it is good practice in the abstract.
Yes, including tenant isolation, per-customer configuration, usage metering, and billing integration. The important part is that isolation is designed in rather than retrofitted, because retrofitting it after the first enterprise security review is substantially more expensive than doing it at the start.
A focused AI application typically reaches first users in 8 to 16 weeks. Adding a well-defined AI feature to an existing product is often 4 to 8 weeks. Multi-tenant products with compliance requirements sit at the longer end. We deliver working software every two weeks, and the evaluation baseline arrives early enough to change direction cheaply.
Next Step

Pressure-test the idea before you build it

A scoping session covers what good output looks like, whether the unit economics work at your expected volume, and what the architecture needs to be. You leave with a written scope and cost range regardless of who builds it.

AI Application & Product Development Services | EnDevSols