Founding AI/ML Research Engineer in London

Transform language models into real-world, high-impact product experiences.

A1 is a self-funded AI division backed by BJAK, operating in full stealth. We\’re building a new global consumer AI application focused on an important but underexplored use case — something practical, meaningful, and far beyond the typical chatbot or productivity agent.

As a Machine Learning Engineer, you will work at the core of our product: fine-tuning frontier-level models, shaping data pipelines, evaluating behavior, and bringing intelligent features into real production environments. You\’ll operate with high autonomy within a small, deeply technical team.

Why This Role Matters

• You will turn state-of-the-art models into real product capabilities used by a global audience.

• You\’ll define how our models behave — accuracy, safety, tone, and user experience.

• You\’ll help build a new consumer AI product from zero, directly influencing its technical and product direction.

• Your work will ensure our models are not only powerful, but safe, reliable, and impactful at scale.

What You\’ll Do

• Fine-tune and adapt models as needed while also designing new model architectures and training pipelines from scratch

• Design and curate datasets, craft prompts, and experiment with alignment and safety strategies for high-quality outputs.

• Build evaluation pipelines for model performance, safety, and alignment, and innovate on new metrics for real-world impact.

• Ship models to production, optimise for latency and scale, and monitor drift or degradation

• Collaborate with product, engineering, and design to launch polished, user-facing AI features

• Explore new modeling approaches, optimisation methods, and product use cases

What It\’s Like to Work Here

• You take ownership – you solve problems end-to-end rather than wait for perfect instructions

• You learn through action – prototype → test → iterate → ship

• You\’re calm in ambiguity – zero-to-one building energises you

• You bias toward speed with discipline – V1 now > perfect later

• You see failures and feedback as essential to growth

• You work with humility, curiosity, and a founder\’s mindset

• You lift the bar for yourself and your teammates every day

Requirements

• Strong experience with transformers, deep learning, and fine-tuning methods (LoRA/QLoRA, SFT, distillation)

• Proficiency in PyTorch (preferred) or TensorFlow

• Experience in prompt engineering and dataset creation for alignment, tone, trust, and safety

• Familiarity with evaluation methods: perplexity, toxicity, relevance, robustness

• Solid software engineering fundamentals — algorithms, data structures, clean code

• Ability to operate in a fast, lean, and high-ownership environment

Nice to Have

• Experience with text generation, moderation, ranking, or personalisation

• Exposure to RLHF or reinforcement learning for LLMs

• Contributions to open-source ML projects

• Background in consumer-facing AI products or high-growth startups

What You\’ll Get

• High ownership and autonomy from day one

• Direct involvement in technical direction and product decisions

• Remote-first flexibility

• A high-impact role with visibility across ML, engineering, and product

• Competitive compensation and performance-based bonuses

• Backing of a profitable US$2B group, with the speed of a startup

• Insurance coverage, flexible time off, and global travel insurance

• Opportunity to shape a new global AI product from zero

Our Team & Culture

We operate as a dense, senior, high-performance team. We value clarity, speed, craftsmanship, and relentless ownership. We behave like founders — we build, ship, iterate, and hold ourselves to a high technical bar.

If you value excellence, enjoy building real systems, and want to be part of a small team creating something globally impactful, you\’ll thrive here.

About A1

A1 is a self-funded, independent AI division under BJAK, focused on building a new consumer AI product with global relevance. We\’re in full stealth and assembling a small, elite team of ML and engineering builders who want to work on meaningful, high-impact problems.