Custom LLM & RAG Development Services
Train AI on Your Data.
Deploy It in Your Systems.
- ISO 27001 Certified
- ISO 22301 Certified
- DORA Aligned
- GDPR Compliant
- Start in 7–10 days
- From €5–6k/mo
HST Solutions builds RAG systems, fine-tunes large language models, and deploys private AI on client infrastructure for organisations across Ireland, the UK, and Europe, ensuring data never leaves your environment. ISO 27001 certified.
Why Custom LLM Development Matters
Off-the-shelf LLMs like ChatGPT are powerful but generic. They don’t know your products, your customers, your internal processes, or your compliance requirements. They can’t access your databases, your documents, or your knowledge base.
Custom LLM development closes that gap. We build systems where AI understands your business specifically — answering questions about your data, following your rules, and integrating with your systems.
There are two primary approaches:
RAG (Retrieval-Augmented Generation): The AI searches your documents and data at query time and generates answers based on what it finds. Best for most business applications. Faster to implement, easier to update, more cost-effective.
Fine-Tuning: We adjust the model’s weights using your training data, teaching it to behave in a specific way. Best when you need the model to adopt a particular style, handle domain-specific terminology, or perform a specialised task consistently.
Most of our clients start with RAG and add fine-tuning later if needed. We’ll advise which approach is right for your situation.
Our Technical Expertise in
Large Language Model Development
- NaturaI Language Processing
Our developers use NLP tools, frameworks and libraries like NLTK. spaCy, and YensorFlow to build custom NLP models equipped with NLU and NLG capabilities to analyze, interpret and generate human language.
- Machine Learning
With proficiency in sciklt-learn, Keras and PyTorch, among other Ml development kits, our developers deploy advanced ML-based solutions trained using prominent learning algorithms, such as supervised, unsupervised and reinforcement.
- Fine-Tuning
We gather data, fine-tune model parametets, customize model architecture, and undertake other vital steps necessary for optimizing pre-trained LLM models, like OpenAI models, BERT, LaMDA, or BLOOM, for specific language-related tasks and domains.
- ln-Context Learning
We use developer resources such as PyText, FastText, and Flair to train and update language models with new data, continuously allowing the model to adapt to new context, domains, and users, improving their peformance over time.
- Few-Shot Learning
- Sentiment Analysis
We utilize developer resources like VADER and NLTK to preprocess and analyze text data and apply machine learning techniques such as Native Bayes to build LLM-based systems that can accurately classify the sentiment of a given text input.
Skip generic consultations.
Our LLM & RAG Development Process
Data Assessment & Preparation
Architecture Design
RAG Pipeline Development
Model Fine-Tuning (When Needed)
Integration & Deployment
MLOps & Continuous Improvement
Technical Capabilities
Pinecone
Weaviate
ChromaDB
pgvector
Qdrant
Milvus
OpenAI Ada
Cohere
Sentence Transformers
custom embeddings
LangChain
LlamaIndex
Semantic Kernel
Haystack
GPT-4o
Claude
Llama 3,
Mistral
Phi
Gemma
custom fine-tuned
LoRA
QLoRA
RLHF
instruction tuning
DPO
spaCy
NLTK
Hugging Face Transformers
Stanford NLP
AWS SageMaker
Azure ML
Google Vertex AI
local GPU clusters
When You Need Custom LLM Development
- Waste is obvious but nobody fixes it
The HST Advantage
Digital Engineering Leadership
Software is core to our business and Generative Al allows us to extend our unmatched software engineering leadership into new Generative Al engagements. We work with clients across industries to use the technology to turbocharge software development, employee and customer services, and workplace processes.
Al Requires Data, & We’re Data Experts
Deep Domain Knowledge
IP, Accelerators & Investments
HST Solutions is
Truly Committed
To The Clients We Serve.
“Nova Leah has been working with HST for the past few years, and our experience has been exceptional. As a startup, we needed a partner who could deliver not just technical excellence but also understand our unique needs and growth pace. HST has more than delivered.
The team's technical expertise is outstanding. They've consistently provided innovative, scalable solutions that align perfectly with our needs. What impresses us most is their flexibility whether it's scaling up quickly or adapting to new requirements, they've been able to pivot and respond swiftly without compromising on quality.
HST feels like a true extension of our in-house team. Communication is effortless, and their proactive approach has fostered a collaborative and transparent working relationship. Despite being an outsourced team, their commitment to our goals and values has been evident from day one.
For any startup looking for a reliable and innovative development partner, HST is a perfect fit. Their understanding of the startup environment, combined with their ability to deliver high quality solutions quickly, has been very impressive.
In summary, HST has been a fantastic partner, the management team have been wonderful to work with - who worked diligently to provide technical excellence, flexibility, and seamless integration with our team. We highly recommend them to any company looking for a top notch software development partner.”
Waystone has been collaborating with HST Solutions for several years now, and our experience has been outstanding. Partnering with HST has significantly helped us develop scalable, secure, and efficient technology solutions that underpin our operations.
HST’s technical expertise is truly remarkable. They've delivered a robust data management framework including customized ETL, a well structured data warehouse, and tailored reporting that aligns seamlessly with our enterprise wide needs. Their ability to adapt to our evolving requirements while maintaining quality has consistently impressed us.
What stands out most is how smoothly HST integrates with our internal teams. Communication is straightforward, and the proactive approach of their developers and project managers fosters a collaborative and transparent working relationship. They’ve quickly become a trusted extension of our workforce, fully committed to our shared objectives.
For any organization aiming to streamline data processes or expand their product offerings based on reliable, single-source data, HST is an ideal partner. Their combination of technical know how, flexibility, and swift turnaround times provides real value and the agility we need to grow.
Frequently asked questions
What is RAG and why do I need it?
RAG (Retrieval-Augmented Generation) is a technique that connects a language model to your business data. Instead of relying only on what the model learned during training, RAG searches your documents and databases at query time and generates answers based on your actual information. This dramatically reduces hallucinations and ensures responses are grounded in your data.
How much data do I need to build a RAG system?
RAG can work with surprisingly little data — even a few hundred documents or knowledge base articles. The more data you have, the more comprehensive the AI’s knowledge becomes, but you don’t need massive datasets to get started. We help you identify and prioritise the most valuable data sources.
Can I keep my data completely private?
Yes. We offer fully on-premises or private cloud deployments using open-source models (Llama, Mistral) that run entirely within your infrastructure. No data ever leaves your environment. This is common for clients in financial services, healthcare, and other regulated industries.
What's the difference between RAG and traditional search?
Traditional search finds documents that match your keywords. RAG reads those documents and synthesises an answer in natural language. Instead of returning 10 links and making you read them, RAG gives you a direct answer with citations to the source documents.
How do you handle document updates?
Our RAG pipelines include automated document processing — when source documents are updated, the system automatically re-processes, re-embeds, and updates the vector store. You don’t need to manually retrain or rebuild anything.
Want to build AI that understands your business?
Tell us about your data and your use case. We’ll design the right LLM/RAG architecture and give you a clear project plan.
Find The Perfect Solutions For Your Project
Managed Team
Your product, our dedicated team. From concept to conception, we handle it all.
Staff Augmentation
Need extra hands? Our experts seamlessly join your team, providing the skills you need, when you need them.
Fixed Cost
One Team, One Dream
Build Trust with Every Interaction
Improve Everything
Own It
Obsessed: Over Results
Proven Excellence
Partners in Precision
Who Are We ?
Creativity, Efficiency, & Advanced AI
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Engineering
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Co-paired AI
Strategy
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Design
Co-paired AI
Contact Us
Tell us about your custom software project
Let our team, be your team
Get a technical conversation about your project not a slide deck. Whether you need AI integration, a software engineering team, or a data platform, we’ll tell you honestly if we’re the right fit.
