Custom LLM Development

Custom LLMs tuned to your domain โ€” not the whole internet.

Generic models are expensive, slow, and wrong in the ways that matter to you. We fine-tune and deploy LLMs built on your domain, your docs, and your use cases โ€” measurably better on accuracy, latency, and cost per query.

  • Benchmarked vs. the base model
  • Runs private, on your hardware
  • You own the weights

Domain accuracy ยท base vs. fine-tuned

Base model ยท 62%
94%

tuned on your data

62% โ†’ 94%

typical domain-accuracy lift

4-bit

quantized, low-cost inference

100%

private deployment option

Hundreds

of examples can be enough

What custom LLM engineering includes

A model that knows your world, served affordably

Four pillars that turn a base model into something cheaper, faster and more accurate on your actual task.

Fine-tuning & alignment

Instruction tuning, LoRA/QLoRA adapters and preference alignment so the model behaves the way your domain demands.

Efficient inference

Quantization, batching and right-sized serving that cut latency and cost per 1k tokens โ€” without surrendering accuracy.

Domain evaluation harness

A benchmark built on your data so 'better' is a measured number, with regression tests that catch quality drops.

Private deployment

Open-weight models served inside your environment โ€” full ownership, no data leaving your boundary, no per-token lock-in.

How we tune

Every gain, provable

We never claim a model is 'better' without a number next to it. Here's the path from base model to a tuned one you can trust.

  1. 1

    Scope & baseline

    We define the task, gather examples, and measure how the best base model already does โ€” so every later gain is provable.

  2. 2

    Tune & quantize

    Fine-tune on your data, then quantize and optimise serving for the latency and cost target you set.

  3. 3

    Evaluate against the base

    Run the harness: accuracy, latency and cost, head-to-head with the base model and human review on edge cases.

  4. 4

    Deploy & govern

    Ship behind a secure inference API with monitoring, versioning and a retraining path as your data evolves.

A model we tuned, in production

Solvent: reading the mess of real bank data

Solvent's whole product depended on one thing โ€” reading raw, messy transactions and categorising them correctly. A generic model wasn't close. A domain-tuned one hit 92% on real data, and became the foundation of the app.

Solvent

Series A consumer FinTech ยท USA

FinTech ยท Personal Finance
Accuracy on messy real-world transactions92% accuracy
Before
generic model
After
92%
Concept โ†’ production modelweeks, not quarters
Before
~a quarter
After
weeks
Dedicated ML hire requiredML hire avoided
Before
1 ML FTE
After
$0
92%

Categorisation accuracy

9 wks

Concept โ†’ live app

$0

Permanent ML hires

7 mo

Runway preserved

โ€œWe pitched the board a vision and a deadline. pyronix handed us a working app two days early. The pod cost us a fraction of the two seniors we almost hired โ€” and we'd have still been onboarding them.โ€
โ€” Founder & CEO, Solvent
FlutterPythonFastAPIPostgreSQLPlaidAWSLLM categorisationRead the full case study

Straight answers

Custom LLM questions

Do we need the latest H100 GPUs to run a custom LLM?

No. We use quantization (4-bit / 8-bit) and right-sized architectures so a tuned model runs efficiently on consumer-grade or older enterprise hardware โ€” often at a fraction of the cost of calling a frontier API at scale.

Fine-tuning vs. prompting vs. RAG โ€” which do we actually need?

Prompting is cheapest and fastest; fine-tuning wins when you need consistent behaviour, format or a specialised skill; RAG wins when answers must reflect current, private knowledge. We benchmark the options against your task and usually combine them rather than betting on one.

How do you measure that a custom LLM is actually better?

We build an evaluation harness on your domain โ€” automated benchmarks plus human-in-the-loop scoring โ€” and report accuracy against the base model before and after tuning. You see the lift in numbers, not adjectives.

How much data do we need to fine-tune?

Less than most teams expect. With transfer learning, instruction tuning and synthetic data augmentation we can get meaningful gains from hundreds to low thousands of good examples. We assess what you have in week one.

Can the model run privately, with no data leaving our environment?

Yes. We can deploy open-weight models entirely inside your cloud or on-prem, so prompts and outputs never leave your boundary โ€” important for regulated and sensitive workloads.

A model that's cheaper, faster, and right.

Send us your task and a sample of your data. We'll benchmark a base model and show you the lift a tuned one would deliver.

2000+ vetted engineers ยท 3 global hubs ยท 98% client retention

Contact Us

for project discussion

Once you fill out this form, our sales representatives will contact you within 24 hours.

2000+
Talents Vetted
3+
International Offices
100+
Project Delivered
50%-70%
Average Cost Saving

Got a project in mind?

We guarantee to get back to you within a business day.