:: AI services / Generative AI development

A generative AI development company for LLM apps you can trust

We build applications on large language models: assistants that answer from your documents, tools that write first drafts, and systems that turn messy text into clean data. The focus is accuracy, cost and keeping your data private.

RAG on your own data

Model-agnostic

Evaluation built in

:: What we do

Generative AI development services

Most generative AI projects are one of these patterns, or a mix of them.

01

Retrieval-augmented generation (RAG)

Search over your documents, wikis and records, with answers that cite their sources. The most common and most useful pattern.

02

Content and document generation

First drafts of proposals, reports, product descriptions and emails, in your format and voice, for a person to review.

03

Data extraction

Turn PDFs, emails and scans into structured fields your systems can use, with confidence scores and review queues.

04

LLM fine-tuning

Training a model on your examples when prompting and retrieval are not enough, or when a smaller, cheaper model can do the job.

05

Private and self-hosted LLMs

Open models such as Llama or Mistral running in your own cloud when data cannot leave your environment.

06

Evaluation and guardrails

Test sets, automatic scoring and filters that catch wrong, unsafe or off-topic answers before users see them.

:: Side by side

RAG or fine-tuning?

The question we are asked most. The short answer: start with RAG, fine-tune only when tests say so.

RAG

Fine-tuning

Best for

Answers from documents that change often

A fixed style, format or narrow task

Keeps answers current

Yes, update the documents

No, needs retraining

Shows sources

Yes

No

Upfront effort

Lower

Higher: needs good training examples

Running cost

Depends on model size

Can be lower with a smaller tuned model

:: RAG vs fine-tuning

RAG vs fine-tuning: how to choose

Most business applications should start with retrieval (RAG). Fine-tuning earns its place in a narrower set of cases, and the strongest systems often use both.

Start here

Use RAG when answers must be current and traceable

The model looks up the relevant passages from your documents at question time and cites them. Updating knowledge means updating documents, not retraining. Best for policies, products, support and internal knowledge.

Specialise

Fine-tune when you need a style, format or skill

Training on hundreds or thousands of examples teaches a model a consistent tone, a strict output format or a narrow task such as classification. It does not keep facts up to date, so it rarely replaces RAG.

Combine

Use both for high-volume, high-accuracy work

A fine-tuned model that follows your format, fed by RAG with current facts. Worth it when volumes are large enough that a smaller fine-tuned model cuts running costs.

:: How it works

How we build generative AI applications

Generative AI is easy to demo and hard to make reliable. Our process is built around measurement.

01

Collect real examples

We gather questions, documents and good answers from your team to build the test set first.

02

Try models and methods

Several models and approaches are tested on the same set. We pick on accuracy, speed and cost.

03

Build the product

Retrieval, prompts, guardrails, user interface, access control and logging, ready for real users.

04

Measure in production

Live scoring, user feedback and cost tracking, with monthly improvements.

:: Quality and safety

How we test generative AI before anyone relies on it

A demo that works on five questions proves little. These are the checks every generative AI system we build goes through before launch, and keeps going through after it.

01

Build a test set from real questions

Collect a few hundred real questions or documents with the answers an expert would give. This set is the yardstick for every change to prompts, models or data.

02

Measure accuracy and groundedness

Score each answer for correctness and for whether it is supported by the source it cites. Answers that cannot be traced to a source are treated as failures.

03

Try to break it

Test with misleading, off-topic and adversarial inputs: attempts to extract data, override instructions or produce harmful content. Fix what gets through.

04

Check cost and speed

Measure cost per answer and response time at realistic volumes, and compare models. A cheaper model that passes the test set is usually the better choice.

05

Monitor in production

Log questions and answers, sample them for review every week, track cost and catch drift when documents or user behaviour change.

:: Cost and timeline

How much does generative AI development cost?

Typical prices for our projects, based on a senior team at $25 to $35 an hour. You get a fixed quote for each phase after a short call.

Prototype

$5k – $12k

3 to 4 weeks

One use case on one document set, tested against your real questions so you can see whether it is good enough before investing more.

Production app

$15k – $50k

8 to 14 weeks

Secure, monitored application with access control, integrations, an evaluation set and a handover to your team.

Platform or custom model

$50k – $120k+

3 to 6 months

Several use cases on shared infrastructure, fine-tuned or self-hosted models, and governance for company-wide use.

What it costs to run

Generative AI is billed per use. For most business apps, model usage runs from tens to a few thousand dollars a month depending on volume, document size and the model. Self-hosted models swap usage fees for GPU hosting costs. We measure the real cost per request during the prototype.

What moves the price

How many document sources and formats

Integrations with your systems

Accuracy and testing requirements

Fine-tuning or self-hosted models

Number of users, languages and channels

:: Why Sterling

How we keep generative AI safe and affordable

Your data stays in your cloud and is not used to train public models

Answers cite sources so people can check them

Automatic tests run on every change

Smaller models used wherever they pass the tests, to cut cost

Role-based access so people only see what they are allowed to

:: Tools we use

OpenAI

Anthropic Claude

Google Gemini

Llama

Mistral

LangChain

LlamaIndex

pgvector

Pinecone

Weaviate

AWS Bedrock

Azure OpenAI

4.9

Average rating on Clutch · 350+ projects since 2019

:: Questions

Questions about generative AI

How much does generative AI development cost?

Which LLM should we use?

What is RAG?

Can we keep our data private?

Do you also advise on generative AI strategy?

What are the most common generative AI use cases?

Should we use RAG or fine-tuning?

Can generative AI run on our own servers?

How do you stop the model making things up?

What does a generative AI app cost to run?

How long does a generative AI project take?

Send us your brief. We’ll help turn it into reality

A senior engineer replies within one business day with questions or a first plan: approach, team, timeline and estimate.

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