All roles

We build the model layer you would hire an LLM engineer for.

Bigcircle does not place engineers. When calling an API is not enough, the model itself has to change: fine-tuning on your rules, structured output that holds at scale, a comparison against the base model, and serving that stays fast without dropping the task. We deliver that as a studio engagement through our fine-tuning and self-hosted model services.

In short

Bigcircle does not place LLM engineers. When calling an API is not enough, our team fine-tunes on your rules, compares the fine-tune against the base model on the same inputs, and changes serving only when that comparison says the task held. On our trademark drafting system, fine-tuning handles structure and register while citations come only from retrieval, because a fine-tune cannot make an authority exist.

Key facts

Definition

An LLM engineer on a Bigcircle team changes the model itself when calling an API is not enough, and publishes the comparison against the base model before a serving change ships.

How Bigcircle does it

  1. Bigcircle vets its own team starting from a model the engineer already shipped.
  2. The exercise breaks the comparison with the base model, and Bigcircle watches the engineer show which model should go out.
  3. On a Bigcircle build the engineer fine-tunes on the client's rules, and distils or quantises only when serving stays fast without dropping the task.

Comparison

An API call leaves the model unchanged, while the LLM engineer on a Bigcircle team fine-tunes against the client's rules and will not change serving until that comparison says the quality held.

At a glance

Fine-tunes compared against the base model on the same inputs, with serving changed only when quality held, built by our team.

See what changing the model involves in production, how Bigcircle compares a fine-tune against the base model, and the three ways to buy that work.

Who this is for
Teams that set out to hire a llm engineer to build a system, and would rather buy the working system.
Topics
  • LoRA
  • PEFT
  • RLHF basics
  • Distillation
  • vLLM
  • Quantisation

What the work involves in production.

  • Fine-tuning and adapting a model on your data and your rules
  • Constraining output to a schema that holds at scale
  • Comparing a fine-tune against the base model on the same inputs before it ships
  • Grounding and self-checks that reduce hallucination at the model layer
  • Distilling and quantising only when serving stays fast and the task holds
  • Benchmarking Claude, GPT, and open models for your specific task

Systems we deliver in this area.

Fine-tuned models for a narrow, high-value task
Reliable structured-output pipelines
Evaluation and regression-testing harnesses
Guardrailed generation for regulated use
Cost-optimised model serving

Tools they reach for in production.

Training
LoRAPEFTRLHF basicsDistillation
Serving
vLLMQuantisationBatchingLiteLLMOpenRouter
Eval
Custom evalsLLM-as-judgeRegression suites
Stack
PythonPyTorchHFClaude / GPT

Who builds it: Bigcircle's core team scopes the system and leads the build. Every engineer on that team cleared five stages of vetting and stays on one product.

Three ways to buy the model layer.

Every engagement is a working system, built in your repositories under your IP by the team that scoped it. The three differ only in how much of the delivery we run.

We finish it

Production hardening

Your team built something that works in the demo and stalls on real inputs. We define what good means and build the eval set, route models for cost and latency, lock down the data path, and put a safety net under it before it takes traffic.

Best when you have a prototype that will not cross into production.

We build it

Fixed-scope build

You bring the problem and we deliver the working AI system. Discovery, build, evals and deployment sit under one point of accountability, against a scope and price agreed before we start.

Best when the problem is clear and you want the result, not a team to manage.

We run it

Studio-led programme

A studio team of engineers and QA, led by our founder as your fractional CTO and architect, owns delivery on your AI roadmap. We run the build rhythm and make the hard technical calls; you bring the product context.

Best when you have a roadmap and no senior AI team to run it.

Choosing between the three is the engagement guide.

Five stages.
The top 3% remain.

Every engineer on the core team that leads your system cleared these before joining. Each stage asks whether they can keep AI running once real customers are using it.

400 applicants

3%of applicants join
the team

What removes them

  1. We start with something they built

    100% → 20%

    One real system, pressed hard. How much traffic did it take? What broke first? Who got the call when it did?

  2. We break something and watch them fix it

    20% → 9%

    A working system with a bug hidden inside it. Anyone can build a demo in a weekend. Fixing code you have never seen is the actual job.

  3. How will you know it is working?

    9% → 5%

    Before they write anything, they have to tell us how they would test it, and what they would do when it gets an answer wrong.

  4. Make it fast without running up the bill

    5% → 4%

    We give them a speed target and a budget, then ask them to explain the tradeoffs they made to hit both.

  5. It is late and the AI got it wrong

    4% → 3%

    What do you do first? How do you find out what happened, undo it, and explain it to the customer in plain words?

Common questions

  • Can I hire an LLM engineer from Bigcircle?

    No. Bigcircle does not place engineers or do staff augmentation. When the model itself has to change, Bigcircle delivers that work as a studio engagement through its fine-tuning, self-hosted models and model routing services, with the comparison against the base model done before anything ships.

  • What model-layer work has Bigcircle shipped?

    Bigcircle fine-tuned the model behind a trademark drafting system in production since 2023, with production logging that compares the base and fine-tuned models on the same inputs. Bigcircle also put a compact, quantized speech model inside a desktop app, running CPU-only, where transcription error rate fell from roughly 18% to 10% across nine rounds of tuning.

  • How does a Bigcircle LLM engagement start?

    Bigcircle starts with a conversation about the model and the task. You get a written scope covering what Bigcircle would build, in what order, and what it depends on from your side, then choose production hardening for a prototype you already have, a fixed-scope build at an agreed scope and price, or a studio-led programme led by our founder as fractional CTO. For model work, the build runs through proving a prompt cannot do it, building the dataset, training and comparing against the base model, and planning the retraining. The work happens in your repositories, and you own the code.

  • Who at Bigcircle builds the model layer?

    Every engineer on Bigcircle's core team cleared five stages before joining, and the top 3% of applicants remain. Vetting starts from a system they already built, then breaks something and watches them fix it. For model work the exercise breaks the comparison with the base model, and the engineer has to show which model should ship. They also say how they would know it is working, how they would make it fast without running up the bill, and what they do first when it is late and the AI got it wrong. They lead client builds as a team.

Services and guides.

Services

Tell us what the hire was meant to build.

Bigcircle does not place engineers. Describe the system and what is in the way, and an engineer replies within two hours on weekdays. A written scope follows within a week.

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