Skip to main content
Viithiisys
Back to blog
AI Engineering6 min readFri, Oct 02, 2026

Custom AI Solutions in the Enterprise LLM Race

Which LLM should an enterprise back? A practitioner's guide to custom AI solutions: model choice, lock-in, retrieval, evaluation and integration.

Gaurav Saini

Founder, Viithiisys

Custom AI Solutions in the Enterprise LLM Race

What does the enterprise LLM race mean for custom AI solutions?

The race means model quality is a moving target and a poor foundation for strategy. Custom AI solutions should treat the LLM as a replaceable component and invest in the parts that stay constant: data access, integration and evaluation.

Every few months a new model tops a leaderboard, and a board member asks whether the company picked the wrong vendor. That question is understandable, but it frames the problem badly. Public benchmarks measure general ability, while your invoice-matching or contract-review task measures something narrower.

At Viithiisys we have shipped 500+ projects since 2007, and the pattern repeats across technologies. The component everyone argues about is rarely the one that decides whether the project works. For AI work, the decisive parts are usually the data pipeline, the integration points and the test set.

Why is betting on a single model risky?

A single-model bet ties your roadmap to one vendor's release cadence, pricing and policy changes. The lower-risk position is to keep models swappable and measure them against your own tasks.

How fast do model choices go stale?

Faster than most procurement cycles. A model that was the best fit when a contract was signed can be outperformed, or deprecated, before the first production release.

Providers retire older model versions on published schedules, and behaviour changes between versions even when the name looks similar. A prompt tuned for one release can regress on the next.

The practical consequence is that you should expect to re-test, and probably re-route, at least once a year. If switching a model takes a quarter of engineering work, the architecture is the problem.

Where does lock-in actually sit?

Lock-in rarely sits in the API call itself. It sits in prompts tuned to one model's quirks, proprietary fine-tuning formats, vendor-specific tool schemas and embeddings generated by one provider.

Embeddings deserve special attention. If your vector index was built with one vendor's embedding model, changing that model means re-embedding the whole corpus, which is a real cost on large document sets.

Keep prompts versioned in your repository, store raw source documents separately from embeddings, and write tool definitions against an open standard where you can.

How do you compare LLM options for an enterprise workload?

Compare options on data residency, latency, failure modes and fit to the task, not on a headline benchmark score. These are the four deployment patterns we see most often:

  • Frontier model via vendor API
  • Strength: highest general capability, no infrastructure to run.
  • Failure mode: data leaves your boundary, and version changes alter behaviour.
  • Typical fit: drafting and reasoning over varied input.
  • Same model via a cloud provider's managed service
  • Strength: existing contracts, regional controls and IAM integration.
  • Failure mode: model versions can lag the vendor's own API.
  • Typical fit: regulated teams already on that cloud.
  • Open-weight model, self-hosted
  • Strength: full control of data and versioning.
  • Failure mode: you own GPU capacity, patching and quality tuning.
  • Typical fit: strict residency and high steady volume.
  • Small fine-tuned model
  • Strength: low latency and unit cost on a narrow task.
  • Failure mode: needs labelled data, and degrades outside its task.
  • Typical fit: classification and extraction at scale.

Most production systems end up using two of these together. A small model handles the high-volume routine step, and a larger model handles the exceptions.

The model is the most replaceable part of an enterprise AI system, so the budget should go to everything around it.

What does a custom AI solution need around the model?

Beyond the model, a working system needs grounding in company data, integration into the systems staff already use, and an evaluation suite. These three layers are where custom AI solutions earn their keep.

How does retrieval ground answers in company data?

Retrieval-augmented generation fetches relevant documents at query time and passes them to the model, so answers reflect your data instead of the model's training. The technique was described in the original RAG paper from Facebook AI Research.

It is not a free fix. Retrieval quality depends on chunking, metadata and permissions, and a model can still ignore or misread relevant context placed in a long prompt, as the Lost in the Middle study showed.

Permissions matter most in an enterprise. If a user cannot open a document in SharePoint, the assistant must not quote it, so access control has to be enforced at retrieval time.

How do models connect to existing systems?

Connection is where many pilots stall. A model that cannot read your ticketing system or write to your CRM remains a demo.

The Model Context Protocol, introduced by Anthropic in late 2024, defines a common way for models to call tools and read data sources. A standard interface reduces the per-model glue code, which directly lowers switching cost.

Whatever the protocol, treat model-initiated actions as untrusted input. Validate arguments, scope credentials narrowly and log every call. Our AI integration work starts from that assumption.

How do you evaluate before rollout?

Build a test set from real tasks before choosing a model. Fifty to a few hundred labelled examples, scored by domain staff, will tell you more than any public leaderboard.

Run the set on every candidate model and on every prompt change, and keep the results. The OpenAI evals guide describes the general method, which applies to any provider.

For governance, the NIST AI Risk Management Framework gives a vocabulary for mapping, measuring and managing risk that auditors recognise.

How do custom ERP, CRM and RPA solutions fit in?

AI layers sit beside existing systems instead of replacing them. The ERP or CRM remains the system of record, and the AI component reads from it, drafts actions and handles unstructured input.

Take a custom ERP solution for a manufacturer. The ERP holds purchase orders and stock, while an LLM reads supplier emails and PDFs, extracts line items and proposes a matched record for a human to approve.

Custom CRM development software solutions follow the same shape: the model summarises account history and drafts follow-ups, but the write to the CRM goes through your normal validation. Custom RPA solutions benefit too, because an LLM can handle the unstructured step that made the old bot brittle, while deterministic rules still govern the money-moving steps.

This is why custom software solutions and AI work are the same discipline. Our enterprise software practice treats the model as one more service with an interface, a failure rate and a fallback.

How should an enterprise team start?

Start with one workflow that has clear inputs, a measurable outcome and a human reviewer. Prove it works on your data, then widen the scope.

What does a 30-day first build look like?

Moonship is how we run this at Viithiisys: a working MVP in 30 days against a fixed scope agreed up front. The fixed scope matters because AI projects drift when the goal is "make it smart".

In practice that means one workflow, a defined test set, two candidate models compared, and a deployed version real users can try. What it does not include is every edge case or every integration. Those come after the evidence is in. See how Moonship works.

When does fractional CTO leadership help?

If nobody in the company owns the architecture, model decisions get made by whoever shouted last. Our CTO-as-a-Service engagements place senior engineering leadership on a fractional basis to set standards for vendor choice, data handling and evaluation.

It suits companies running several AI pilots at once, where the risk is five incompatible stacks. It is less useful if you have one small pilot and a capable internal lead. Read more about fractional CTO support.

What is the practical next step?

Map where your current workflows break before choosing a model, because the break points decide where AI helps. A short broken workflow assessment is how we find them with clients in the US, UK, Canada and beyond.

Our engineering team works from Mohali, with a Canadian office in Markham, Ontario, and has delivered for clients including Paytm, Snapdeal, IKEA, Nestle, Shiprocket and Vikram Solar. Custom enterprise solutions and custom application development solutions are scoped per project after a discovery call, not from a rate card.

If you already know your use case and want to talk it through, use the contact form.

FAQ

What are custom AI solutions?
Custom AI solutions are AI systems built around one organisation's data, workflows and constraints, rather than bought as a generic product. They usually combine one or more LLMs with retrieval over company data, integrations into existing systems, and an evaluation suite that measures accuracy on the organisation's own tasks.
Should an enterprise standardise on a single LLM provider?
Usually not. Model rankings change within months, and pricing and terms shift. A thin abstraction layer that lets you route tasks to different models costs little at the start and avoids a rewrite later. Standardise on your retrieval, evaluation and integration layers instead.
How long does it take to ship a first custom AI solution?
A narrow, well-scoped use case with clean data access can reach a working version in about a month. Viithiisys runs Moonship for this: a working MVP in 30 days against a fixed scope. Broad ambitions with messy data sources take longer and should be split into stages.
Do custom AI solutions replace ERP, CRM or RPA systems?
No. They usually sit alongside them. The ERP or CRM stays the system of record, and the AI layer reads from it, drafts actions, or handles unstructured inputs that rule-based RPA cannot. Writes back into those systems should go through the same validation as any other integration.