London

Senior AI / LLM Engineer

Job type
Full Time
Level
Mid-senior level
Apply now

Your Role

We’re hiring a Senior AI / LLM Engineer to design and industrialise the core AI capabilities that will power ASOS.

At ASOS, AI is central to how we evolve the customer experience — from product discovery and personalisation through to operational decision-making. You’ll work on systems that operate at real scale, supporting experiences used by millions.

This role sits at the centre of our AI differentiation — focused on solving deep technical problems (models, reasoning systems, orchestration), not just feature delivery. You’ll create reusable, production-grade AI platforms that teams across ASOS can leverage, accelerating how we build and scale intelligent products.

We’re looking for someone who thinks in systems, not features — with strong abstraction capability and a mindset of building once and reusing at scale. You’ll be comfortable operating in ambiguity, working on frontier AI problems, and balancing innovation with the realities of production environments.

If you’re motivated by solving complex challenges and seeing your work adopted across a global platform, this is a high-impact opportunity.

Responsibilities

  • Design and build LLM-powered systems (RAG, fine-tuning, tool use, multi-agent orchestration)
  • Develop agentic workflows for automation, reasoning, and conversational experiences
  • Define patterns for autonomous + human-in-the-loop systems
  • Build and scale solutions on the Azure AI stack (Azure OpenAI, AI Studio, Azure ML, Cognitive Services)
  • Create reusable infrastructure: Prompt orchestration layers, Vector search and retrieval pipelines & Evaluation and observability frameworks
  • Design and implement LLM evaluation frameworks (offline + online)
  • Implement AI safety guardrails (hallucination control, filtering, explainability)
  • Partner with Trust & Security to embed AI risk controls by design
  • Build reusable AI capabilities (e.g. stylist reasoning, product understanding, copilots)
  • Enable horizontal reuse across squads — building once, scaling many times
  • Optimise systems for performance, cost, and reliability (token-aware design)
  • Champion best practice in AI engineering, governance, and platform thinking
  • Support a culture of inclusive, responsible AI development

/01 Company Description

We're ASOS, the online retailer for fashion lovers all around the world.

We exist to give our customers the confidence to be whoever they want to be, and that goes for our people too. At ASOS, you're free to be your true self without judgement, and channel your creativity into a platform used by millions.

Everyone needs some help showing up as their best self. We're Disability Confident Committed - let our Talent team know if you need any reasonable adjustments throughout the recruitment process

/02 Job Qualifications

Tech stack & platform experience (core):

  • Strong hands-on experience with the Azure AI ecosystem — including Azure OpenAI, Azure AI Studio, and Azure Machine Learning
  • Experience building and running production-grade AI systems on cloud infrastructure (APIs, event-driven architectures, scalable compute such as AKS or similar)
  • Proficiency in Python, with experience working across modern AI frameworks (e.g. Semantic Kernel, LangChain or equivalents)

LLM systems and architecture:

  • Deep understanding of LLMs and transformer-based models, including embeddings, tokenisation, and context management
  • Experience designing and optimising LLM-powered systems, including fine-tuning approaches, structured prompting, and model selection trade-offs
  • Experience building end-to-end RAG pipelines, including retrieval strategies, vector search, and grounding techniques

Agentic systems & orchestration:

  • Experience designing agent-based systems, including multi-agent patterns, tool usage, and workflow orchestration
  • Understanding of state, memory, and event-driven pipelines in conversational or decisioning systems

Quality, safety & production readiness:

  • Experience implementing evaluation frameworks to measure model quality and performance
  • Strong understanding of AI safety, governance, and guardrails (hallucination mitigation, content safety, explainability)
  • Experience designing secure, scalable, and cost-efficient systems in production environments

Nice to have:

  • LLMOps / MLOps experience (CI/CD, experiment tracking, observability)
  • Performance and cost optimisation (caching, batching, model routing)

/03 Additional Info

BeneFITS’

  • Employee discount (hello ASOS discount!)
  • Employee sample sales
  • 25 days paid annual leave + an extra celebration day for a special moment
  • Discretionary bonus scheme
  • Private medical care scheme
  • Flexible benefits allowance - which you can choose to take as extra cash, or use towards other benefits
  • Opportunity for personalised learning and in-the-moment experiences that enable you to thrive and excel in your role
what our people say what our people say what our people say what our people say what our people say what our people say what our people say what our people say what our people say what our people say what our people say what our people say what our people say what our people say what our people say what our people say

Meet The Team

Meet Zijiao Li -
Tech @ ASOS

Meet Amy Richardson -
Tech @ ASOS

Meet Si Jobling -
Tech @ ASOS

I love working at ASOS in my team because of the great atmosphere. From day one I already felt like being part of the team, everyone is so friendly, approachable and willing to help. It’s the place where you feel trusted and are given the opportunities & time to explore your full potential. As someone who just relocated to London, I also appreciate the international and cultural diverse environment – it’s ok to be whoever you want to be!
As a software engineer with a love for fashion, I feel extremely lucky to be part of a fashion company that priorities technology, innovation and customer experience to the same degree as their clothing.
As someone who left ASOS after 7 years but came back, it speaks volumes how much I love working at ASOS. The obvious reason is the people, not just in Tech but beyond. There's an unspoken respect and authenticity between everyone who works here
  • Zijiao Li

    Tech @ ASOS

    I love working at ASOS in my team because of the great atmosphere. From day one I already felt like being part of the team, everyone is so friendly, approachable and willing to help. It’s the place where you feel trusted and are given the opportunities & time to explore your full potential. As someone who just relocated to London, I also appreciate the international and cultural diverse environment – it’s ok to be whoever you want to be!
  • Amy Richardson

    Tech @ ASOS

    As a software engineer with a love for fashion, I feel extremely lucky to be part of a fashion company that priorities technology, innovation and customer experience to the same degree as their clothing.
  • Si Jobling

    Tech @ ASOS

    As someone who left ASOS after 7 years but came back, it speaks volumes how much I love working at ASOS. The obvious reason is the people, not just in Tech but beyond. There's an unspoken respect and authenticity between everyone who works here
our business values our business values our business values our business values our business values our business values our business values our business values our business values our business values our business values our business values our business values our business values our business values our business values
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We are Customer First

We couldn’t be ASOS without our customers.

Across every behaviour, value, and all that we do, we see everything through our customers’ eyes. That means never taking anything for granted and always zeroing in on every single detail. So we can always bring our best as a team, and our customers can have an amazing experience, every time. 

We are Authentic

We work together to be honest, transparent, and our full authentic selves.

This is our ASOS. Our culture, built on collaboration and togetherness, and supported by what’s real and honest. We know that we win bigger when we win as a diverse team. That means celebrating our differences and using them to help us stand out from the crowd, without losing our authenticity and individuality.

We are Brave

We challenge each other to aim high and reach our potential.

Doing nothing gets us nowhere. We may be proud of everything we’ve done so far, but there’s still so much more to explore. We believe we can always be wiser, faster, stronger, bigger, braver, kinder…so asking ‘why’ isn’t just a question, it’s a necessity. We use our voice to drive us forward, speaking up on the things our people and customers care about and using our curiosity to create possibility. 

We are Creative

We know innovation leads to inspiration – it’s what makes us stronger

Change is in our DNA. By acting fast and staying one step ahead of the curve, we can be a leader, not a follower. But for our products and platform to be innovative, they have to be fuelled by creative passion and a deep understanding of our customers and our people. 

We always Deliver

We couldn’t be excellent without evidence – so whatever we’re doing, we have proof of why we’re doing it.

It takes facts and data to tell our stories and help us make our decisions in the most effective way possible. This means we can do what we say and own what we do, no matter how long it takes us to do it. We aren’t about nonsense ifs, buts and maybes, we’re about creating an ASOS that’s built for future success on delivered success. 

Our Benefits

  • Employee Discount

    The most asked-about benefit! As an ASOSer, you’ll receive an exclusive employee discount. You can also nominate a family member or friend to share your discount with.

  • Pension

    Retirement might not be on your mind right now, but it’s important to prep for it. We offer matched contributions up to 5% to help you save.

  • Private Medical Care scheme

    If you join our Private Medical Care scheme, you’ll get fast and effective access to medical cover. 

  • Bonus

    What we achieve is always a team effort. That’s why we offer a discretionary bonus scheme which rewards you based on our group financial and strategic performance.

  • Celebratory Day!

    Get an extra day off in addition to the 25 days of annual leave you get! Spend it celebrating the big days in life, whether it’s birthdays, cultural holidays, weddings and anything else.

  • Shuttlebus Service (if you're based in our Leavesden office)

    It’s more of a work perk, but we offer a free shuttlebus between Watford station and our office in Leavesden.

  • Sample Sales

    We’ve always got fun things happening in our offices, but the one ASOSers get most excited about is our sample sales. Plus, all proceeds from the sample sale get donated to the ASOS Foundation, which helps our charity partners abroad. 

  • Career Development

    You’ll have the opportunity for personalised learning and in-the-moment experiences to create a dynamic and agile learning environment that empowers you to thrive and excel in your role.

  • Summer Hours

    We finish at 3pm on Fridays in June, July and August!! This perk doesn’t mean a dip in your salary – it just gives you extra freedom to enjoy those summer weekends however you want.

Location

Our HQ in London

Our HQ in Camden was once a cigarette factory – now, the iconic Art Deco building has been completely renovated with spacious office areas, ASOS Studios (where we shoot all our products), beauty rooms and a free gym. There’s also a subsidised canteen and café. 

Recruitment
Process

  1. Apply online

  2. Call back & Interview

  3. Decision & Onboarding