Custom AI development UK startups and enterprise teams actually ship, built for real problems not pitch deck theatre. LLMs, RAG pipelines, and intelligent automation that earns its place in your product.
An API call to GPT with a branded skin is not an AI product. It is a cost centre with no moat. When the API changes pricing, breaks, or gets rate-limited, your entire feature goes down. Your users do not care whose model is underneath. They care that it works.
Most AI integrations go live without proper evaluation. The model confidently returns wrong answers, your support team gets buried, and user trust evaporates. By the time you notice the accuracy problem, the damage to your brand is already done.
LLM inference is expensive when it is not optimised. Without caching, model routing, and prompt engineering strategy, your AI costs grow faster than your revenue. What looked affordable in testing becomes a serious liability at scale.
We are an AI development agency UK founders call when a demo has to become a product, and we build AI software that earns its place in the product, evaluated, optimised, and monitored from day one.
See what you get →Every build includes the same core package. It is the baseline any AI development agency UK businesses hire should be held to, and none of it hides behind a tier.
End-to-end inference system deployed in your infrastructure with monitoring, failover, and cost controls.
Accuracy benchmarks, latency metrics, cost projections, and edge case analysis documented.
Tested, versioned prompts with documented reasoning for every decision.
API contracts, usage guides, and data flow diagrams your team can build on.
Caching layers, model routing, and usage controls that keep your bill predictable.
Model tuning, edge case fixes, and drift monitoring covered after go-live.
If any of these describe you, we will tell you on the first call rather than waste your time or ours.
Founder at Seconddate
Foundry 5 really impressed me with their work on my AI-powered dating app. They nailed the UI/UX, starting with core app screens and then translating that vision to the web. The React site they built is sleek and polished - exactly what I was hoping for. What I appreciated most was their thoughtful approach and how easy they were to work with. They got the job done without needing me to micromanage.
CEO at StreaksAI
Foundry 5 surpassed all expectations in delivering our web development product swiftly and flawlessly. Their speed and eye for detail, especially under tight time constraints, showcase their commitment to excellence.
CEO, Xcelsior Capital
Working with Foundry 5 has been a great experience from start to finish. They seamlessly translated our vision into a website that not only showcases our brand and operations but also enhances our online presence as an investor in natural resources. Nothing was too much for them and they always put the client first.
CEO of Ove
Working with Foundry 5 to create the Ove app has been an absolute pleasure. Their professionalism, work ethic, and willingness to always go the extra mile has really impressed me. I would recommend them to anyone.
Loom Founder
Foundry 5 have gone above and beyond to bring my vision of Loom to life. Not only this, but they continue to be an integral part of our team. They are lovely people to work with, and I recommend them to anyone looking for a software partner. Particularly for non-technical tech founders (like me!) who need to ensure that their business is in safe hands.
Chief Product Officer Gather
The team has been instrumental in driving both the design and development of Gather, pairing a proactive, highly responsive workflow with the technical depth needed to handle our platform's complexity. Their partnership continues to move the product forward in a reliable and impactful way.
| Feature | Foundry 5 | Freelancer | In-house |
|---|---|---|---|
| Production-grade AI pipeline | |||
| Model evaluation before deployment | |||
| Cost optimisation built in | |||
| Adversarial testing and edge cases | |||
| Post-launch drift monitoring | |||
| Honest assessment of AI fit | |||
| Full source code ownership | |||
| Prompt library with versioning |
Pricing an AI development agency UK founders can plan around: we scope the work, agree a price, and stick to it. No surprise invoices. No scope creep charges. If something changes, we talk about it before it costs you anything. You get a written scope document before code starts.
For ongoing AI development or projects where the model needs continuous refinement. You reprioritise at the start of each sprint. Pay for what gets built, adjust as you learn.
Anything else? Just book a call. We'd rather talk than write another FAQ entry.
✓Risk-free first project · Full refund if you’re not satisfied
Both, depending on your use case. Most products are best served by fine-tuned versions of existing models combined with smart retrieval. Custom training is expensive and slow. We only recommend it when the data and use case genuinely demand it. We will tell you which approach is right on the first call.
Through a combination of retrieval-augmented generation, output validation, confidence scoring, and guardrails. We test every AI feature against adversarial inputs and edge cases before it ships. Zero hallucinations is not realistic, but we build systems that know when they do not know.
It depends on the complexity. A straightforward LLM integration might take two to three weeks. A custom AI pipeline with retrieval, evaluation, and monitoring runs four to eight weeks. We scope honestly and give you a number before code starts.
Yes. Most of what we do is AI integration services for UK businesses that already have a product and users, rather than standalone AI builds. We work with your existing APIs, databases, and infrastructure. If the backend needs adjustments to support it, we handle that too.
We are an AI development agency UK businesses hire to build and ship the system, not to hand over a slide deck and leave. Strategy is part of the work, and we will tell you plainly if AI is the wrong tool, but the deliverable is running software your team owns outright. If advice is genuinely all you need, our AI consulting engagements cover that on its own.
Whichever one wins on your data. We build on OpenAI, Anthropic, and Mistral, and we fine-tune open-weight models when cost or data residency demands it. LLM development is not a loyalty contest: we benchmark the candidates against your real inputs, compare accuracy, latency, and cost, and route between models where that is cheaper than committing to one.
Yes, where the problem genuinely needs one. AI agent development earns its place when a task takes several steps, tool calls, and decisions that cannot be written out in advance. It is the wrong answer when a single prompt or a plain script would do. Agents also fail in ways that are hard to debug, so we scope them narrowly, give them explicit tools, and keep a human in the loop wherever a wrong action costs money.
Caching, prompt optimisation, model routing, and usage controls. We build cost monitoring into every AI pipeline so you can see exactly what you are spending and why. No one should be surprised by their inference bill.
Thirty days of post-launch support is included. This covers model tuning, edge case fixes, and drift monitoring. After that, most clients move into an ongoing engagement for continuous improvement. AI is not set-and-forget. It needs ongoing attention.
Yes. We have turned down AI projects on the first call because a simpler solution would serve the client better. We would rather lose the project than build something that does not make sense. That honesty is why clients come back for other work.
Tell us the problem you want solved with AI. We are an AI development agency UK teams come to for a straight answer, and we will tell you plainly whether custom AI development is right here, or whether you are better off without it.
✓Risk-free first project · Full refund if you’re not satisfied
