LLM Development & Custom Fine-Tuning Built for Production

ScalaCode builds and deploys custom large language model solutions , fine-tuning on LoRA, QLoRA, DPO, and RLHF; serving on vLLM, Triton, and NVIDIA NIM; eval harnesses on golden datasets; observability pipelines for drift detection , for enterprises across 45+ countries. With 13+ years of model deployment experience, our teams take LLMs from frontier-API experiments to production-grade systems running inside your perimeter, with the cost economics and reliability your finance team can defend.
Whether you need to fine-tune Llama 3.3 on proprietary data, deploy Qwen 3 in an air-gapped environment, build evaluation harnesses for a multi-tenant agent platform, or migrate from OpenAI to a self-hosted Mistral or DeepSeek stack to control unit economics, our LLM engineers architect solutions that move the metrics that matter , accuracy on your domain, inference cost per request, time-to-deploy.

Trusted by Startups, ISVs, and Fortune 500 Teams Since 2012

LLM Development Services We Deliver

Custom LLM Fine-Tuning

Domain-adapt frontier and open-source LLMs to your data , legal, medical, financial, technical vocabulary; brand voice; internal-policy reasoning. We use parameter-efficient fine-tuning (LoRA, QLoRA, IA3) for cost-effective adaptation and full fine-tuning when the domain shift demands it. Typical outcome: 15 to 35 point quality lift on domain-specific tasks vs base models at <5% of full-fine-tune cost.

Domain-Specific LLM Pre-Training

For organisations with massive proprietary corpora (10B+ tokens of clean domain text), we lead continued pre-training on a base model , typically Llama 3.3 8B / 70B or Qwen 3 , to bake domain understanding into the weights themselves. Used by clients in pharma, financial services, and legal where retrieval alone isn’t enough.

Preference Optimisation (DPO / RLHF / RLAIF)

Align fine-tuned models to human preferences using Direct Preference Optimisation (DPO), Reinforcement Learning from Human Feedback (RLHF), or Reinforcement Learning from AI Feedback (RLAIF). Used to align models with brand voice, regulatory tone, or specific decision-making patterns. Critical for high-stakes generative use cases.

LLM Serving Infrastructure

vLLM for high-throughput open-source LLM serving (continuous batching, paged attention, multi-LoRA serving). NVIDIA Triton + TensorRT-LLM for GPU-optimised production deployments. NVIDIA NIM for enterprise-grade microservice serving. SGLang for structured generation. We design serving infrastructure for your latency budget, throughput requirement, and cost constraints.

Model Selection & Routing

For multi-LLM stacks (the production default in 2026), we build smart routing layers that pick the right model per request based on complexity, latency budget, sensitivity classification, and cost. GPT-5 for nuanced reasoning, Claude Sonnet 4.6 for long-context analysis, Gemini 2.5 Flash for high-volume cheap calls, fine-tuned open-source for domain-specific deterministic tasks. Smart routing typically delivers 5 to 15× cost advantage versus single-model architectures.

Evaluation Harnesses

Every LLM we ship is paired with a custom eval use , golden datasets, automated metric tracking, human-in-the-loop validation panels, regression detection. Built on OpenAI Evals, Anthropic eval tooling, LangSmith, Braintrust, or custom frameworks. Without rigorous evaluation, LLM quality silently regresses as prompts and models evolve. We treat the eval use as a first-class production deliverable, not an afterthought.

Prompt Engineering Frameworks

Production prompt engineering goes far beyond writing clever instructions. We build prompt templates with structured outputs (JSON schema validation), few-shot example selection patterns, chain-of-thought scaffolding, tool-use protocols, and meta-prompting layers. Codified in versioned prompt registries with eval-gated deployment.

LLM Observability & Operations

Production LLM stacks need traces (every prompt, response, latency, cost, model version), drift detection (output quality regression alerts), token-budget tracking per tenant / workflow / user, and incident response for prompt injection or output-quality incidents. Built on LangSmith, Langfuse, Helicone, Arize Phoenix, OpenTelemetry.

On-Premises & Sovereign LLM Deployments

For data-sovereignty, regulated, or air-gapped environments, we deploy open-source LLMs (Llama 3.3, Qwen 3, Mistral, DeepSeek) on customer infrastructure , vLLM / Ollama / Triton / NVIDIA NIM. AWS GovCloud, Azure Government, India MeitY-empanelled regions, customer-owned datacenters, hybrid-cloud topologies all supported.

2026 LLM Engineering Patterns We Implement

Reasoning Models for Planning, Fast Models for Execution

OpenAI o-series or Claude Sonnet 4.6 with extended thinking for the hard reasoning step. GPT-4.1 / Gemini 2.5 Flash for fast tool-calls and execution. Splitting these layers delivers 5 to 15× cost advantage vs always-using-reasoning-models architectures while retaining the reasoning quality where it matters.

Smart Routing Across the Frontier

Production LLM stacks route across multiple models per request. Classifier picks: “this request is high-stakes with regulatory implications → GPT-5; this is high-volume Tier-1 support summarisation → Llama 3.3 fine-tune; this is creative drafting → Claude Opus 4.6.” Routing decisions are evaluated and refined over time.

Structured Outputs Everywhere

Every model output is constrained to a JSON schema using OpenAI’s structured outputs feature, Anthropic’s tool-use JSON validation, Outlines, or external validators (Pydantic, Zod). Eliminates the “model returned malformed JSON” failure mode. Required for any LLM output that feeds a downstream system.

Long-Context Workflows

1M-token context windows (GPT-5, Claude Sonnet 4.6, Gemini 2.5 Pro) enable workflows that were previously impossible , entire contracts, multi-document research, full codebase analysis. We design retrieval + ranking patterns for context windows in the 100K-1M token range, plus context-summarisation strategies when even 1M isn’t enough.

Multi-LoRA Serving for Per-Customer Customisation

vLLM and SGLang now support efficient multi-LoRA serving , one base model serves many customer-specific LoRA adapters from a single GPU. Lets multi-tenant SaaS deliver per-tenant fine-tuned behaviour without provisioning a separate model per tenant. 50 to 100× cost reduction vs separate model deployments.

Speculative Decoding & Draft-Then-Verify

Production-mature in 2026. Smaller draft model proposes tokens; larger model verifies. Delivers 2 to 4× throughput improvement for compatible workloads with no quality regression. Available natively in vLLM, TensorRT-LLM, and NVIDIA NIM.

Eval-Gated Deployment

No prompt change, fine-tune, or model swap reaches production without passing the eval use. Evals run on every PR, on every nightly cron, on every model version bump. Quality gates block deploys automatically. This is the single most important LLM-ops practice.

Related AI Capabilities That Compose With LLMs

Hire Our LLM Engineering Team

Need LLM expertise embedded in your own team? We staff senior LLM engineers with 3+ years of production fine-tuning, serving, and evaluation experience.

How We Engineer Production LLM Systems

  • Production LLM Engineering Discipline

    We treat LLMs as production systems with eval harnesses, observability, drift monitoring, and rollback paths , not as research projects. Most LLM programs we’re called in to fix were demos that got rushed into production without these foundations.

  • Vendor-Neutral by Design

    We work with whichever model fits the workload , frontier or open-source , and decouple business logic from model specifics so swapping is a config change, not a rewrite. When a better model lands, you benefit without re-engineering.

  • Cost Engineering as a First-Class Concern

    Production LLM stacks routinely burn 5 to 10× more than they should because no one designed for cost economics. Smart routing, structured outputs, multi-LoRA serving, speculative decoding, and disciplined prompt design typically cut LLM bills 60 to 80% with no quality regression.

  • Domain Adaptation Expertise

    We’ve fine-tuned LLMs for healthcare, legal, financial services, and regulated industries , including the data-curation, annotation-quality, and evaluation rigour that off-the-shelf consultants skip. Our domain-adapted models routinely outperform off-the-shelf APIs by 15 to 35 points on domain tasks.

  • On-Premises & Sovereign Deployments

    We’ve shipped LLM stacks to customer datacenters, AWS GovCloud, Azure Government, India MeitY-empanelled regions, and air-gapped environments. Open-source serving infrastructure (vLLM / Triton / NIM) is part of our default toolkit, not a bolt-on.

  • End-to-End Delivery

    Model selection, fine-tuning, serving infrastructure, evaluation, observability, governance, and ongoing operations under one roof. No handoffs to a system integrator that loses context.

Industries Where We've Shipped LLM Systems

Guaranteed Regulations Compliance

Legal

Custom LLMs for contract review, clause extraction, regulatory change summarisation, case-law research. Often paired with GraphRAG architectures for precedent and clause-relationship reasoning.

Retail & E-Commerce

LLMs for product description generation at scale, conversational shopping assistants, customer review summarisation, sentiment-tagged catalog enrichment. Often paired with our sentiment analysis solutions for review-driven product insights.

SaaS product black icon

SaaS & Enterprise Software

Multi-tenant LLM platforms with per-customer LoRA fine-tuning. Custom in-app copilots. AI-powered admin assistants. Embedded analytical reasoning. We've shipped LLM features for SaaS clients with single-day fine-tune-to-deploy pipelines.

Engineering & Developer Tools

Code-completion models (custom Code Llama, DeepSeek Coder fine-tunes), code-review assistants, internal-documentation generators. Integrated with GitHub Copilot extensions, JetBrains plugins, or custom IDE integrations.

Engagement Models for LLM Development

LLM Discovery & Architecture Sprint (2 to 4 weeks)

Workload audit, model selection benchmarking on your data, fine-tuning vs prompt-engineering decision, serving architecture proposal, cost projection. Starting at $25k-$50k.

Custom Fine-Tuning Engagement (4 to 10 weeks)

Data curation, annotation, training, evaluation, deployment to production serving infrastructure. Includes eval use setup. Typical price $80k-$300k depending on model size and data complexity.

Full LLM Platform Build (3 to 6 months)

Custom LLM stack with multi-model serving, smart routing, fine-tuning pipeline, eval harnesses, observability, governance, multi-tenant isolation. Typical for SaaS clients building LLM features as a platform capability.

Domain-Specific Pre-Training

For organisations with massive proprietary corpora. Continued pre-training of an open-source base model on your domain data. 6 to 12 weeks engagement; price scales with corpus size and target model.

Dedicated LLM Engineering Team

Embedded squad , LLM engineer, ML engineer, MLOps engineer, eval specialist, infrastructure engineer , running with your team for 6+ months.

Managed LLM Operations

Post-launch operations: eval re-runs on model updates, prompt drift management, cost optimisation, incident response, new model evaluation as the frontier evolves. SLA-backed.

Our Clients’ Success Stories

LLM Development Technology Stack

Foundation Models

OpenAI GPT-5 GPT-4.1 o-series Sonnet 4.6 Opus 4.6 Haiku 4.5 Google Gemini 2.5 Pro / Flash Llama 3.3 / 4 Mistral Large / Small / Pixtral Qwen 3 DeepSeek-V3 / R1 Phi-4 Gemma 3 BioGPT FinBERT LegalBERT custom-pretrained models

Fine-Tuning Frameworks

Hugging Face Transformers + PEFT Axolotl LLaMA-Factory Unsloth Together AI fine-tuning API OpenAI fine-tuning API Anthropic fine-tuning API Custom training pipelines

Preference Optimisation

TRL OpenRLHF Custom RLAIF pipelines

Serving

vLLM NVIDIA Triton + TensorRT-LLM NVIDIA NIM SGLang Together AI inference Anyscale Endpoints Anthropic API OpenAI API Azure OpenAI Service AWS Bedrock Google Vertex AI

Evaluation

OpenAI Evals Anthropic eval tooling LangSmith Langfuse Braintrust Promptfoo RAGAS HELM Custom golden-set frameworks

Observability & Cost

LangSmith Langfuse Helicone Arize Phoenix Weights & Biases OpenTelemetry Custom cost-attribution dashboards

Safety & Guardrails

Llama Guard OpenAI Moderation API NVIDIA NeMo Guardrails Lakera Guard custom classifier guardrails

Training Infrastructure

AWS Trainium SageMaker GCP Vertex AI Training Azure ML CoreWeave Lambda Labs Customer-owned GPU clusters DeepSpeed FSDP Megatron-LM

LLM Outcomes We've Delivered

Top-5 European bank

Llama 3.3 70B fine-tuned on internal regulatory corpus for KYC reasoning. Domain accuracy 71% → 94%. Replaced GPT-4 calls for KYC pipeline; cost per case dropped 89%.

US healthcare network

Domain-pretrained Llama 3.3 8B for prior-authorization reasoning (HIPAA-bounded, on-prem). Auth turnaround time 5.1 days → 11 hours. Denial rate dropped 27%.

Enterprise SaaS

Multi-LoRA serving for 240 customer-specific fine-tunes on a single base model. GPU footprint cut 95% vs separate-model baseline. Per-customer customisation latency <200ms.

Tier-1 retailer

Smart routing across GPT-5 / Claude Sonnet 4.6 / Gemini Flash / Llama fine-tune for product description generation. LLM bill cut 73% with quality scores held within 1 point of always-GPT-5 baseline.

Legal tech vendor

DPO-aligned Mistral Large for contract clause extraction. Output passed senior-paralegal review on 92% of test cases vs 67% for prompt-engineered Claude 4.6 baseline.

Customer support platform

Eval use rollout caught 14 prompt regressions in first month that would have shipped to production. Quality stability +18 points on user-facing CSAT scores.

Frequently Asked Questions

up-chevron-icon