Forward Deployed AI Engineer

Apprentify Group; City of Westminster; On-site; GBP 90,000 - 130,000; Full time

Job summary

Calibr, part of The Apprentify Group, is seeking a Forward Deployed AI Engineer to work directly with clients to scope problems, build solutions and leave them more capable than when you arrived.

You will turn a scoped business problem into well-bounded technical components, build guardrails and evaluation loops, and ensure AI delivery is efficient, explainable and trustworthy for stakeholders. Travel to client sites may be required; remote work options exist.

Qualifications

• Building stress-tested cloud systems that have made it to production and had measurable impact (3+ years).
• Shipping AI harnesses involving RAG, document intelligence and custom tools, with a focus on evaluation pipelines, model routing, and agent/tool orchestration and permissions.
• Working with Python (including FastAPI), LangChain (and LangGraph where necessary), SQL and scalable (vector) databases.
• Enforcing rigorous evaluation to cover edge cases and determine specific mitigations for prompt injection and tool abuse.
• Distinguishing a model safety issue from an application security issue.

Responsibilities

• Decompose ambiguous problems into smaller components and map out their dependencies and operational risk before production.
• Determine the right set of tools (harnesses, models, custom tools and MCP servers).
• Code the underlying plumbing and necessary automations to enable the design of the system while embedding it in a pre-existing architecture.
• Build observability channels to monitor the health of the system and allow for user-accessible fixes.
• Bound your builds with schemas, evaluation sets and permissions for human review to enable transparency.
• Explain architecture decisions, their trade-offs and risks in terms non-technical stakeholders can act on.

Skills

Cloud systems

AI harnesses

Python

LangChain

LangGraph

SQL

Vector databases

Evaluation pipelines

Prompt injection

Model safety

Tools

FastAPI

LangGraph

SQL

Vector databases

Job description

Location: London, United Kingdom.

Contract: Freelance, with the possibility of future full-time employment.

About the job:

AI is forcing engineers to evolve like never before. The role is increasingly defined by deciding what a system should do and which specs and evals to write, then handing execution to agents and carefully checking what comes back. The best engineers we know still understand every layer underneath and are eager to spend more time thinking about how and why the solutions they build get used.

That’s who we want to work with at Calibr, a startup founded by Peter Wood and Marlene Leiss, and part of The Apprentify Group, one of the UK’s leading AI and tech training providers. We build tailored AI solutions for companies going through AI transformation, then help their teams build the skills to run, extend and own those systems themselves. As a Forward Deployed AI Engineer, you’ll work directly with clients to scope the problem, build the solution and leave them more capable than when you arrived.

Who we are:

Our mission at Calibr is to help companies build in-house AI capability. Our approach is simple: help businesses identify where AI can create the most value, prove it in a focused part of the business and build the capability to navigate AI adoption long term.

We are industry-agnostic and work with the UK’s leading SMEs, scale-ups, corporates, NGOs and public sector organisations. Our group’s clients include Jet2, JD Group, Canon, BBC, B&Q, McLaren and Manchester Airport, to name a few.

The Apprentify Group is a collective of six specialist businesses, including Netcom Training, Flourish, Ioda, The Juice Academy and Apprentify. We are united by a shared commitment to providing learning opportunities to people at every stage of their career, and in 2025 we were named the UK’s 30th-fastest-growing private company by The Sunday Times.

Who we are looking for:

We are looking for a technically competent orchestrator (i.e. someone who can explain the decisions behind their code and develop it in ways that respect wider architectures) to help build transformation projects for clients.

Your goals will be to turn a scoped business problem into well-bounded technical compositions, build tested and evaluated guardrails, and create feedback loops that involve humans, resulting in AI-assisted delivery that is efficient yet explainable and trustworthy.

What you will do

• Decompose ambiguous problems into smaller components and map out their dependencies and operational risk before production.

• Determine the right set of tools (harnesses, models, custom tools and MCP servers).

• Code the underlying plumbing and necessary automations to enable the design of the system while embedding it in a pre-existing architecture.

• Build observability channels to monitor the health of the system and allow for user-accessible fixes.

• Bound your builds with schemas, evaluation sets and permissions for human review to enable transparency.

• Explain architecture decisions, their trade-offs and risks in terms non-technical stakeholders can act on.

What you bring

We understand that this is a new and emerging role, so we focus far more on the signals we receive from you as a candidate than on the job title on your CV. You are, however, likely to be a match if you have demonstrable competence in the following areas:

• Building stress-tested cloud systems that have made it to production and had measurable impact (3+ years).

• Shipping AI harnesses involving RAG, document intelligence and custom tools, with a focus on evaluation pipelines, model routing, and agent/tool orchestration and permissions.

• Working with Python (including FastAPI), specifically LangChain (and LangGraph where necessary), SQL and scalable (vector) databases.

• Enforcing rigorous evaluation to cover edge cases and determine specific mitigations for prompt injection and tool abuse.

• Distinguishing a model safety issue from an application security issue.

Travel: This role may require being on-site with clients.

How we work:

As part of The Apprentify Group, we have the backing, client relationships and commercial experience of a group that has already scaled several businesses. You get the pace and ownership of an early-stage startup with a stable foundation behind it.

As a Forward Deployed AI Engineer, you’ll work directly with the founders, our fractional CTO and, where needed, our clients. We want you to have a real say in how we build, from the tools we standardise on to how we run client projects.

We know that the people who join us at this stage will shape what Calibr’s engineering practice looks like for years. Culture is important to us, and we look for people who thrive in work environments that value:

• Infectious Ambition. We believe every high-agency person should have a “why” that sustains them and motivates others to strive for greatness as a team.

• Efficient Conscientiousness. We care about the details but move fast. Finding the balance between depth and iteration is essential to how we build.

• Radical Kindness. Being kind is more than being nice. For us, radical kindness requires the courage to be honest, even when it causes discomfort and disruption.

What we offer:

• The opportunity to join a warm and creative founding team, supported by experienced scalers and sellers at The Apprentify Group.

• Real ownership of your work. We give all our people the trust, resources and agency they need to succeed.

• Top-of-market day rates for project-based work.

• Based in our London office, with occasional travel to our other offices.

• Flexible hours; remote working can be arranged.

• Regular company-wide events and team socials.

• All IT equipment provided, with a MacBook or Windows machine depending on your preference.

• Career progression and the possibility of future full-time employment.

Interview process:

Your suitability will be assessed over two rounds. First, you’ll have a brief call with one of our co-founders to assess culture fit and synergy. If we think you’re a good fit, we’ll invite you to a technical interview, where you’ll demonstrate your capabilities by walking us through a project of your choice. You’ll be evaluated not only on your ability to build efficient systems but also on how well you can explain and defend the system you built.

Please note: This role is contract-based, and you will work with clients on custom-spec projects. We attract projects from a wide range of industries, giving you experience across various domains. Your tracked performance and synergy with the team can lead to future full-time employment.

At Calibr, we are committed to creating a diverse and inclusive workforce that reflects the communities we serve. We welcome and encourage applications from people of all backgrounds and value different perspectives, lived experiences and ways of thinking.