Senior AI Engineer

Planna Ltd.; Cardiff, London; Hybrid; GBP 80,000 - 100,000; Full time

Job summary

Planna Ltd., an innovative AI startup, is seeking a Senior AI Engineer to handle real-world challenges using advanced AI technologies like LLMs and computer vision. This high-impact, hands-on role will involve building scalable AI systems, collaborating with clients, and shaping internal AI practices in a flexible, hybrid work environment.

Benefits

Equity options

New MacBook

Online learning subscription

28 days holiday (plus your birthday off)

Annual pay review

Friendly and supportive work environment

Qualifications

• 3+ years of hands-on AI/ML experience.
• Experience deploying LLMs and computer vision models in production.
• Strong communicator comfortable discussing model architecture.

Responsibilities

• Build production-grade AI systems and solve complex problems.
• Fine-tune and deploy LLMs for RAG pipelines.
• Collaborate with enterprise clients to develop AI solutions.

Skills

AI/ML experience

LLMs

Computer vision

AWS

Communication

Education

PhD or equivalent in machine learning, computer vision, NLP, or related field

Tools

AWS services (Lambda, EC2, S3, SageMaker)

MLOps tools (Weights & Biases, SageMaker, MLflow)

Job description

Location: Cardiff or London
Employment Type: Full time
Location type: Hybrid
Compensation: £80-100K

About Us

We’re a fully funded AI startup, based in Hammersmith and soon opening our second office in Cardiff.

At Planna, we build tools that help people make smarter decisions about their homes — whether that’s diagnosing a boiler issue, planning a loft conversion, or finding a trusted roofer. Our patent-pending AI technology cuts through the noise and helps homeowners figure out what really matters, whether they want to save money, live more sustainably, or boost the long-term value of their biggest asset.

We also work with banks, insurers, and household brands to offer the right products to the right customers at the right time — powered by real-time insights into every home.

With growing monthly users and major partnerships in the works, it’s a great time to join us and help shape what comes next.

The Role

We’re looking for aSenior AI Engineerto join our growing team at the forefront of applied AI. You’ll work on meaningful, real-world challenges with clients across the UK — using state-of-the-art LLMs, computer vision, and NLP to build innovative solutions that deliver real impact.

This is a broad, high-impact role, perfect for someone who thrives in fast-paced environments, combines technical depth with strong product instincts, and enjoys turning complex problems into working products.

Who You Are

• You’ve got 3+ years of hands-on experience in AI/ML — with a solid mix of practical application and research depth.
• You’ve worked with LLMs and/or computer vision models in real-world settings, and you know what it takes to get them into production.
• You’re confident with AWS — from setting up infrastructure to building training pipelines and deploying models at scale.
• You thrive in fast-paced environments and enjoy seeing your work ship quickly.
• You’re proactive, solutions-focused, and comfortable working with uncertainty.
• You’re a strong communicator — equally at home discussing model architecture or product impact.
• You’re based in (or happy to travel to) either Cardiff or London 2–3 days a week.

Bonus points if you also have:

• A PhD (or equivalent research experience) in machine learning, computer vision, NLP, or a related field
• Experience with multi-modal models that combine vision and language
• Strong grasp of data-centric AI practices — annotation tooling, prompt evaluation, and dataset curation
• Familiarity with MLOps tools (e.g. Weights & Biases, SageMaker, MLflow)
• Experience working in regulated sectors like insurance, banking, or property

What You’ll Be Doing

This is a hands-on, high-impact role — you’ll be building production-grade AI systems, solving complex problems, and working closely with enterprise partners. No two weeks will look the same.

• Fine-tune and privately deploy LLMs — with a focus on Retrieval-Augmented Generation (RAG) pipelines
• Build and scale computer vision systems — from object detection to image segmentation
• Apply NLP to real-world business problems — summarisation, entity recognition, information extraction, and more
• Train and deploy models at scale using AWS — including Lambda, EC2, S3, and SageMaker
• Meet with enterprise clients to explore problems, present ideas, and share results
• Prototype fast, test often, and get working solutions into the hands of users
• Work cross-functionally with product and engineering teams to bring AI features to life
• Help shape our internal AI practices — from evaluation frameworks to responsible deployment

What We Offer

• Equity options
• New MacBook
• Online learning subscription
• Flexible hybrid working (2–3 days a week in our Cardiff or London office)
• 28 days holiday (plus your birthday off)
• Annual pay review
• Autonomy, ownership, and the chance to shape a growing company
• A friendly, supportive work environment where work-life balance matters

How to Apply

Send us your CV and a short cover letter telling us why this role is a great fit for you.

Interview Process

• You’ll start with a coffee chat either in Cardiff or London with one of our senior team members
• Technical Deep Dive
• Then a follow-up call with our CEO and founder
• Team Fit + Final Q&A

To apply email your CV and cover letter to [e-mail]