Posted October 10, 2025
Guest Article

How to Implement an LLM in a Firm

This guest contribution was written by:

Bringing an LLM into your firm is a lot like deciding how you’ll eat. We’ve already covered the ingredients you will need to make an AI strategy real. Now comes the architectural choice: do you completely outsource the cooking to a restaurant, hire your own private chef who learns your tastes or co-hire a chef in a shared cloud kitchen?

So how will you balance speed, safety, cost and culture to choose the architecture that fits?

Why This Matters

Each executive sees a different facet of the LLM - cost, security, compliance, adoption or speed of delivery and each perspective is valid. The real challenge is harmonising them into a single, coherent strategy.

So which option best fits your firm’s appetite?

Strategic Option 1: Completely Outsource the Cooking / Off-the-shelf LLMs

This is the enterprise version of ChatGPT, Claude, Gemini - the ready-to-serve option.

The strengths are obvious: quick to adopt, no chefs or setups required, constant upgrades at no extra effort. For a subscription fee, anyone in the firm can order.

But you give up control. You don’t know exactly what’s in the recipe, neither do you know how the dish was prepared nor can you change it. Sensitive data may leave your walls and when the restaurant changes its menu or pricing, how would you avoid a lock-in?

Still, the opportunity is huge. It’s the fastest way to experiment and democratise access across teams. The threat is regulatory scrutiny, reputational risk from model “hallucinations” and the cost keeps creeping as you scale.

Strategic Option 2: Hire Your Own Private Chef / Self-developed LLMs

Think BloombergGPT or firms fine-tuning Meta AI’s LLaMA. Here you bring the chef in-house, stock the pantry and shape the menu around your exact tastes.

The upside is control. Every dish is prepared to your specifications with ingredients that never leave your home. Done well, this becomes a strategic asset - tailoring meals that no restaurant could replicate.

The biggest downside is time to market. This demands significant investment in cutting-edge hardware hardware (like NVIDIA GPUs), expertise to manage data systems and highly skilled staff - all of which adds up quickly. Set-up can take months or even years and once built, you are hook for every upgrade, every cleanup, every experiment.

The opportunity is leadership: to build something unique, deeply woven into workflows, defensible as intellectual property and hard for rivals to copy. The threat is equally sharp: talent wars, rapid obsolescence, high resource costs and the risk of investing heavily before the first meal ever hits the table.

Strategic Option 3: Co-hire a Chef in a Shared Cloud Kitchen / Hybrid or Hosted LLMs

This is co-hosted enterprise solutions in Cloud. For example, Open AI APIs co-hosted in Microsoft Azure. Here you don’t run a full kitchen yourself but you share access to a professionally managed one. You co-hire a skilled chef who uses their ovens, equipment and safety standards - while still letting you bring in your own recipes and ingredients.

The strength is balance. You can customise outputs with your own data, while leaning on big vendor’s infrastructure for scale, compliance and security. You can start faster than a full build but with more control than outsourcing everything.

Weaknesses include partial dependency. Costs can scale unpredictably. Integration work to connect the shared kitchen to your existing processes often involves complex orchestration and data synchronisation challenges, limited transparency into how the underlying model “cooks” results.

The opportunity lies in leverage from rich vendor ecosystems making adoption smoother. The threat is lock-in: once your recipes depend on one provider’s kit, it’s hard to leave.

Tactical Option: Korean BBQ / Tools like Copilot

Then there are tools like Microsoft Copilot - think Korean BBQ. The grill and the ingredients are provided but you need to cook the meal yourself at the table.

The upside is accessibility: these tools are built into apps people already use and can deliver quick productivity gains.

The catch? These meals are only as good as the diners’ skills - without training, some come out perfect, others burnt.

This is a halfway solution. Useful tactically but not a substitute for a deliberate LLM architecture.


A Quick Summary of the Trade-offs:

Other Considerations
  • Supportability: Ovens need repair crews and the team composition depends on the option chosen.

  • Sustainability and cost: Training a single large LLM can consume as much energy as several homes in a year - are you tracking how the costs scales with usage?

  • Adoption: The best appliances mean nothing if nobody wants to cook or can cook.

  • Regulation: Health inspectors are on the way, from the EU AI Act to SEC disclosures to UK guidance.

Do you want the speed of a restaurant kitchen, the control of a custom-built private kitchen or the balance of a shared kitchen?

Maybe the real question isn’t about kitchens at all - it’s about the kind of organisation you want to become. Do you want ultimate control, keeping everything in-house? Are you comfortable with standard, ready-made meals if they’re safe and cost-efficient? Or do you prefer co-hiring a chef in a shared kitchen, balancing speed with some control? Your choice reflects your priorities, risk appetite and long-term vision.

Proprietary kitchens take years to build and many firms won’t see a competitive advantage worth the cost. At the same time, letting data leave your walls may feel risky but with safeguards it’s often manageable. The real choice is where your firm can truly differentiate and how long you are willing to wait for it.

About the authors

Larry is a lifelong technologist with a strong passion for problem-solving. With over a decade of trading experience and another decade of technical expertise within financial institutions, he has built, grown, and managed highly profitable businesses. Having witnessed both successful and unsuccessful projects, particularly in the banking sector, Larry brings a pragmatic and seasoned perspective to his work. Outside of his professional life, he enjoys Brazilian Jiu-Jitsu, climbing and solving cryptic crosswords.
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Ash is a strategy and operations professional with 14 years of experience in financial services, driven by a deep passion for technology. He has led teams and projects spanning full-scale technology builds to client-facing strategic initiatives. His motivation comes from connecting people, processes, data and ideas to create solutions that deliver real-world impact. Beyond work, Ash enjoys exploring different cultures through food and cocktails and practices yoga regularly.
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