◆ LLM Engineering Services Company

LLM systems engineered to be accurate, affordable and production-ready

Getting an LLM to answer is easy. Getting it to answer correctly every time, grounded in your data, fast enough to wait for and cheap enough to run at scale — that is engineering. We build and rebuild LLM applications, RAG systems and AI agents with the architecture, evaluation and observability production actually demands.

4.9★★★★★
4.8★★★★★
5.0★★★★★
🎯
100%Answers grounded and source-cited
📉
-40%Typical token cost cut through optimisation
3–6 wksFrom architecture review to production-grade

Enterprises, SMEs and fast-growing teams trust ZTS India

The real blockers

The LLM engineering challenges that hold you back

LLM adoption is accelerating, but most teams hit the same wall between a working demo and a reliable, affordable production system. Click a panel to see the challenge, how we fix it, and what changes.

01No context, no accuracy
Grounding & Accuracy

Confident answers. Wrong answers.

The model has no access to your documents, your policies or your data, so it fills the gap with something plausible. Two bad answers in front of a customer and your team quietly stops trusting it.

💡Our fix: Retrieval rebuilt properly — chunking, embeddings and re-ranking tuned on your content — with citations enforced on every answer and a refusal path when confidence is low. Grounded by default, not by luck.
100%answers source-cited
Refusalinstead of invention
Tunedretrieval, not generic defaults
02Chatbot, not an agent
From Chat to Action

It can talk about the task. It cannot do the task.

Your assistant answers questions beautifully and then tells the user to go and do it themselves. Every real action still needs a human, so the savings never arrive.

💡Our fix: We turn conversation into execution: tool-using agents with scoped access to your systems, planning logic, approval gates where a mistake costs money, and an audit trail of every action taken.
Actsnot just answers
Approval gateswhere it matters
Auditedevery action logged
03Won't scale
Cost & Performance

It works for ten users. It dies at a thousand.

Latency climbs, the token bill triples in a quarter, and every request goes to the most expensive model whether it needs to or not. Nobody budgeted for the cost of success.

💡Our fix: Model routing so cheap requests use cheap models, plus caching, prompt compression, streaming and batching — engineered against an explicit cost and latency budget rather than discovered on the invoice.
-40%typical token cost
Sub-2sp95 latency targets
Budgetedcost per request
04Flying blind
Monitoring & Governance

In production, with no idea how it is doing

No traces, no quality signal, no cost breakdown, no audit trail. You find out the system degraded when a customer complains — and you cannot prove what it said or why.

💡Our fix: Full observability: request tracing, automated quality scoring, drift and cost dashboards, and audit logs your risk team can actually read. Problems surface before your customers find them.
Tracedevery request
Scoredquality, automatically
Auditableend to end
05Prompt roulette
Evaluation

Every prompt change fixes one thing and breaks another

Someone tweaks a prompt, the demo looks better, and three other behaviours regress silently. With no test set, "improvement" is just the last person's opinion.

💡Our fix: An evaluation harness built before the tuning starts — a golden test set, automated scoring, and regression checks in CI. Changes ship because the numbers moved, not because the demo felt better.
Golden setregression-tested
CI-gatedprompt changes
Evidenceover opinion
What we build

Our LLM Engineering Services

We design and build production-grade LLM systems, RAG architectures and AI agents — so you can move from experimentation to something your business can actually depend on.

End-to-end LLM products engineered for production from the first commit — architecture, evaluation, guardrails and observability built alongside the features, not bolted on before launch.

  • Solution architecture & model selection
  • Streaming, caching & async pipelines
  • Evaluation harness from day one
  • Cost and latency budgets
Build an LLM application →

Retrieval that actually retrieves the right thing. We tune chunking, embeddings and re-ranking on your own content, enforce citations, and make retrieval permission-aware per user.

  • Ingestion, chunking & embedding strategy
  • Hybrid search & re-ranking
  • Permission-aware retrieval
  • Citation enforcement & refusal paths
Build or fix a RAG system →

Agents that complete multi-step work across your tools — with planning, scoped permissions, approval gates and a full audit trail of every action taken.

  • Tool use & function calling
  • Planning & multi-step orchestration
  • Human-in-the-loop approvals
  • Action logging & rollback
Build an AI agent →

Prompts are code. We version them, test them and measure them — engineering context windows, structured outputs and system instructions that behave the same on the thousandth call as the first.

  • System prompt & context design
  • Structured & schema-validated outputs
  • Prompt versioning & regression tests
  • Few-shot & example curation
Optimise our prompts →

Fine-tuning when it earns its cost — and honest advice when it does not. Most accuracy problems are retrieval problems wearing a fine-tuning costume.

  • Fine-tune vs. RAG decision framework
  • Dataset curation & labelling
  • LoRA / QLoRA parameter-efficient tuning
  • Benchmarking against the base model
Discuss fine-tuning →

The difference between a demo and a product. Golden test sets, automated scoring, hallucination and bias checks, and red-teaming before anything faces a customer.

  • Golden test sets & automated scoring
  • Hallucination & groundedness checks
  • Safety filters & refusal behaviour
  • Red-teaming & adversarial testing
Evaluate our LLM →

Connect LLM systems to the CRM, ERP, helpdesk and internal tools your teams already work in — securely, with SSO and role-based access, and without a rebuild.

  • Secure API & middleware integration
  • SSO, RBAC & scoped credentials
  • Legacy system connectivity
  • Phased, low-risk rollout
Integrate our LLM →

Run LLMs like software. Tracing, quality scoring, cost dashboards and alerting so accuracy holds and spend stays predictable long after launch day.

  • Request tracing & observability
  • Automated quality & drift scoring
  • Token & infrastructure cost dashboards
  • Continuous tuning & release governance
Operationalise our LLM →
Our track record

AI excellence, backed by numbers

More than a decade delivering measurable results for enterprises, SMEs and technology companies worldwide.

15+Years in software engineering
250+Projects delivered
100+AI, data & software engineers
350+Global clients
91%Client retention
4.9★Average client rating
50+LLM systems shipped
24/7Support & monitoring
Case studies

LLM Engineering Case Studies

Three systems that demoed well and needed engineering to survive production.

Healthcare

A RAG system that stopped making things up

Challenge: The assistant answered confidently from the wrong document. After two bad answers in front of clinicians, nobody opened it again.

Solution: We rebuilt retrieval — chunking, hybrid search and re-ranking tuned on their corpus — added a golden test set, enforced citations and built a refusal path for low-confidence queries.

0ungrounded answers in eval set
100%source-cited
96%answer accuracy
Retail & E-commerce

From chatbot to an agent that finishes the job

Challenge: The bot answered questions but every action needed a human. Deflection stalled at 20% and the support queue never moved.

Solution: We rebuilt it as a tool-using agent with scoped order-system access, approval gates on refunds above a threshold, and a full action audit trail.

55%auto-resolved
3 min → 20sto resolution
Fullaction audit trail
Financial Services

Same quality, 40% less token spend

Challenge: The monthly LLM bill tripled in a quarter and p95 latency sat at eight seconds. Every request hit the most expensive model available.

Solution: Model routing so simple requests use small models, plus semantic caching, prompt compression and streaming — validated against the existing evaluation set so quality held.

-40%token cost
8s → 1.4sp95 latency
No dropin eval scores

LLM app that demos well but breaks in production?

Get a free 30-minute architecture review. We'll look at your retrieval, evaluation and token spend, and tell you the three things worth fixing first — no pitch.

Get My Free Architecture Review →
Model-agnostic

Foundation Models & Platforms We Engineer With

Rarely one model. We benchmark candidates on your task and your data, then route between them — a small model for the easy 80%, a large one for the rest.

GPT-4o

OpenAI

Strong general reasoning and multimodal support — a dependable default for broad workloads.

Claude

Anthropic

Long-context and instruction-following strength — our usual pick for document-heavy RAG.

Gemini

Google

Natively multimodal with long context and tight Google Cloud integration.

Llama

Meta

Open weights, self-hostable — when data cannot leave your infrastructure at any price.

Mistral / Mixtral

Mistral AI

Efficient open models — often the right router target for high-volume, simple calls.

Command R+

Cohere

Built for retrieval workloads, with citation support as a first-class feature.

Amazon Bedrock

AWS

Multi-model access inside your own AWS account, with enterprise controls and residency.

Azure OpenAI

Microsoft

Enterprise governance and regional data residency for regulated workloads.

How we work

Our LLM Engineering Process

A structured, outcome-driven path to designing, building and scaling LLM systems — with accuracy, cost and reliability treated as requirements, not hopes.

1

Discover

Define the use case, the accuracy bar it must clear, and the cost and latency it must live within.

2

Architect

Retrieval design, model selection and system architecture against those budgets — before code.

3

Engineer Context

Chunking, embeddings, retrieval, re-ranking and prompts tuned on your actual content.

4

Evaluate

Build the golden test set and automated scoring first, so every later change is measurable.

5

Optimise

Model routing, caching, compression and streaming to hit the cost and latency targets.

6

Guardrail

Safety filters, groundedness checks, refusal behaviour and red-teaming before launch.

7

Integrate

Deploy into your stack with SSO, RBAC and a phased rollout with a fallback path.

8

Monitor

Tracing, quality scoring, drift and cost dashboards — then iterate against the numbers.

Let's engineer your LLM system properly

Book a free, no-obligation architecture review. We'll assess your retrieval, evaluation, cost and guardrails, and give you a costed plan with a realistic timeline.

★★★★★ Rated 4.9/5 across Clutch, Google & GoodFirms
Deep expertise

Technical Expertise of Our LLM Engineers

The depth production LLM systems actually need — retrieval, evaluation, agents, cost engineering, guardrails and observability.

📚

RAG Architecture & Retrieval Tuning

Chunking, hybrid search, re-ranking and permission-aware retrieval that returns the right context, not just nearby text.

✍️

Context & Prompt Engineering

System design, structured outputs, prompt versioning and regression testing — prompts treated as code.

🧪

LLM Evaluation & Benchmarking

Golden test sets, automated scoring, groundedness and hallucination measurement, model bake-offs.

🤖

Agent Design & Orchestration

Tool use, planning, multi-step execution, approval gates and recovery from partial failure.

🎛️

Fine-Tuning & Model Adaptation

LoRA / QLoRA, instruction tuning and dataset curation — with honest advice on when not to bother.

💰

Token Economics & Latency

Model routing, caching, compression, batching and streaming against explicit cost and latency budgets.

🛡️

Guardrails & Responsible AI

Safety filters, refusal design, PII redaction, bias testing and red-teaming before customers see it.

🔁

LLMOps & Observability

Tracing, quality monitoring, drift detection, cost dashboards and CI/CD for prompts and models.

🧩

LLM Integration & Architecture

APIs, middleware and event pipelines that put LLM output inside the tools your teams already use.

Our toolkit

Technologies We Leverage for LLM Engineering

A modern LLM stack aligned to your accuracy, cost, latency and data-residency requirements — chosen per workload, not by habit.

Foundation Models & LLMs

OpenAI Anthropic Claude Google Gemini Meta Llama Mistral AI Cohere

Vector Databases & Large-Scale RAG

Pinecone Weaviate Qdrant Milvus pgvector Elasticsearch

Orchestration & Frameworks

LangChain LlamaIndex Haystack Semantic Kernel DSPy Instructor

Agentic AI & Multi-Agent Frameworks

LangGraph CrewAI AutoGen OpenAI Agents SDK Model Context Protocol Swarm

LLMOps, Evaluation & Monitoring

LangSmith Langfuse Ragas DeepEval Weights & Biases Arize Phoenix

Cloud, Serving & Enterprise Infrastructure

AWS Bedrock Azure OpenAI Vertex AI vLLM Ray Serve Kubernetes
Where we work

Industry-Specific LLM Use Cases

LLM systems, agents and RAG applications designed to automate decisions, lift productivity and deliver measurable outcomes across industries.

Client voices

What Our Clients Say

The reason most of our clients come back for the next system.

Video Testimonials

Why ZTS India

Why Businesses Choose ZTS India for LLM Engineering

A partner that treats accuracy, cost and reliability as engineering problems with owners — not as things you hope improve.

🧪

Evaluation-led, not vibes-led

Every change is measured against a golden test set. If we can't show you the number moved, we don't ship it.

💰

Cost and latency are engineering targets

Model routing, caching and compression treated as first-class work — not something to worry about after the invoice.

📚

Grounded by default

Retrieval tuned on your content, citations enforced, and a refusal path when the system is not confident.

🏭

Production-first architecture

Observability, guardrails and failure paths designed in from the first sprint, not retrofitted before launch.

🔐

Secure & governed

Permission-aware retrieval, PII handling, audit trails and data-retention policy defined before we connect anything.

🤝

One team, end to end

Retrieval, models, integration, frontend and DevOps under one roof. Nothing lost between vendors.

Ready for an LLM system you can trust in production?

Tell us what you've built and where it's falling short. We'll come back with an honest assessment, the fixes that matter most, and a transparent estimate — free.

No obligation · Response within 1 business day · NDA on request
Good to know

Frequently Asked Questions

The discipline of turning a language model into a reliable product. It covers architecture, retrieval design, prompt and context engineering, evaluation, guardrails, cost and latency optimisation, integration and production monitoring. Calling an API is the easy part; everything around it is the engineering.

The API gives you an answer. Engineering is what makes that answer correct on your data, consistent across thousands of calls, fast enough for a user to wait for, cheap enough to run at scale, safe enough to show a customer, and observable enough to debug at 2am. That gap is where most LLM projects fail.

Usually, yes. In our experience most hallucination is a retrieval problem, not a model problem — the right context never reached the model. We start with an audit of retrieval quality and evaluation, and in many cases fixing chunking, re-ranking and citation enforcement solves it without changing the model or rebuilding the app.

RAG in most cases. Fine-tuning teaches style, format and tone; it does not reliably teach facts, and it goes stale the moment your data changes. If the problem is "the model does not know our information", that is retrieval. If it is "the model does not sound like us or follow our format", that may be fine-tuning. We will tell you which honestly, including when the answer is neither.

With a golden test set built from real questions and verified answers, plus automated scoring for groundedness, correctness and format compliance. We build it before tuning starts, so improvements are provable and regressions get caught in CI rather than by a customer.

Typically a lot. The common wins are model routing so simple requests stop hitting your most expensive model, semantic caching for repeated queries, prompt and context compression, and batching. We validate every optimisation against your evaluation set so cost drops without quality following it.

It depends on the workload, and often the answer is more than one. We benchmark candidates on your actual task with your data, weighing accuracy, cost, latency and data residency — then usually route between a small model for easy calls and a larger one for hard ones. We are model-agnostic and resell nobody.

Yes. Options range from enterprise APIs with no-training guarantees and regional residency, through to fully self-hosted open models where data never leaves your infrastructure. We add permission-aware retrieval so users only ever see what they are entitled to, plus PII redaction and audit logging.

By giving it scoped tools rather than more instructions. We define the actions it may take, wire them to your systems with least-privilege credentials, add planning logic for multi-step tasks, put approval gates wherever a mistake costs money, and log every action for audit.

It depends on scope. An architecture and evaluation audit is a small fixed-price engagement and often pays for itself in token savings alone. Full builds are priced fixed-scope or as a monthly dedicated team. The initial architecture review call is free.

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