Senior Fullstack Engineer - AI (GTM)

About Allica Bank

Allica is the UK’s fastest growing company - and the fastest-growing financial technology (Fintech) firm ever. Our purpose is to help established SMEs, one of the last major underserved opportunities in Fintech.

Established SMEs are the backbone of local communities - representing over a third of our economy - yet have been largely neglected both by traditional high street banks and modern fintech providers.

Department Description

Growth is a critical function at Allica, sitting at the intersection of marketing, product, sales, and data. Our team is responsible for driving sustainable and scalable customer acquisition, engagement, and retention—ensuring our banking solutions reach and resonate with the right SMEs at the right time. Growth is both a science and an art. We blend commercial strategy with deep customer understanding, leveraging data to uncover new opportunities while ensuring every touchpoint aligns with Allica’s mission to empower established SMEs with the banking they deserve.

Role Description

The Senior Fullstack Engineer will be a founding member of our AI capability within the Growth Squad, responsible for applying advanced large language models (LLMs) to solve complex customer and operational challenges. This role will create significant value for Allica by building agentic AI systems that either eliminate manual effort or transform the customer experience — through intelligent automation, smarter interfaces, and proactive service.

Working closely with growth, data, product, and operations teams, this role will scope, design, and deploy real-world AI use cases across marketing, onboarding, and customer lifecycle journeys (including initiatives in advertising platforms and our CRM, HubSpot). You will bring deep expertise in LLMs, prompt engineering, agent frameworks, and systems thinking to build scalable, explainable, and impactful solutions.

This is a high-impact technical role with clear business outcomes. You’ll own the end-to-end delivery of AI solutions — from idea to production deployment and monitoring — and play a pivotal role in shaping how we scale Allica using AI. You will continuously fine-tune and optimize models for performance, manage their versioning, and establish robust evaluation and monitoring processes to ensure each solution remains reliable, efficient, and safe in production.

Principal Accountabilities

• LLM Application Development: Design and build agentic LLM systems that automate manual processes or transform customer interactions across key stages of the growth funnel.

• AI Solution Delivery: Lead the end-to-end development of AI tools and agents using frameworks like LangChain or Semantic Kernel, ensuring scalable and maintainable deployment, including fine-tuning models and optimizing performance to meet latency and cost constraints

• Model Deployment & Monitoring: Ensure robust deployment of AI models to production, including proper versioning and continuous monitoring, leveraging tools like MLflow, FastAPI, and Kubernetes (or other cloud-native services) to maintain high reliability and performance

• Workflow Automation & Experience Design: Identify high-impact use cases with operations, product, and lifecycle teams, creating AI-driven solutions that improve efficiency or elevate customer experience.

• Experimentation & Iteration: Rapidly prototype AI applications, run experiments to test impact, and iterate based on usage data and feedback.

• Cross-Functional Collaboration: Partner with growth, marketing, engineering, and data teams to prioritize AI initiatives, align on business goals, and integrate solutions into operational systems.

• AI Safety & Explainability: Apply best practices in responsible AI deployment, ensuring explainability, compliance, and ethical use of LLMs in production environments.

• Evaluation & Optimization: Design and implement rigorous evaluation frameworks (including custom pipelines) to test model performance, quality, and safety. Compare vendor-provided models vs. open-source alternatives for overall quality, bias, and compliance, ensuring we deploy the optimal solutions

• Innovation & Strategic Impact: Drive innovation through continuous learning and experimentation, ensuring AI solutions align with Allica’s long-term growth strategy and customer-centric values.

Personal Attributes & Experience

Personal Attributes:

• Deeply curious, proactive, and impact-driven with a strong bias for action and experimentation.

• Comfortable operating in ambiguous, fast-paced environments where the problem is as novel as the solution.

• Collaborative and communicative, able to translate technical ideas into business language and influence stakeholders.

• Passionate about the potential of AI to change how businesses work and how customers interact with products.

Experience & Technical Skills:

• 3+ years’ professional software engineering experience in one or more programming languages (preferably Python and Kotlin).

• Proven experience building and deploying LLM-powered tools or agents (e.g., using OpenAI, Claude, or open-source models).

• Hands-on expertise in Python, LLM frameworks (LangChain, Semantic Kernel, etc.), prompt engineering, and orchestration.

• Knowledge of model deployment, versioning, and monitoring in production (e.g., using MLflow, FastAPI, Kubernetes, or similar cloud-native tools)

• Experience integrating AI solutions into real-world systems (e.g., CRM platforms like HubSpot, advertising platforms, ticketing systems, or internal tools).

• Experience fine-tuning and optimizing LLMs, including building efficient embeddings or vector memory stores, while managing latency and cost constraints

• Understanding of privacy, bias, and safety considerations when applying LLMs in production.

• Strong understanding of vector databases, RAG (retrieval augmented generation), and agent workflows.

• Understanding of privacy, bias, and safety considerations when applying LLMs in production.

• Experience evaluating AI models for quality and fairness, including comparing vendor models vs. open-source alternatives and building custom evaluation pipelines to validate model performance.

• Comfortable with full-stack development (e.g., building web interfaces or APIs) to integrate AI solutions end-to-end.

• Exposure to business domains like growth, marketing automation, or customer service is a plus.

This is a unique opportunity to shape how AI drives growth at Allica—designing powerful, intelligent systems that scale what our teams can do and reimagine how customers experience business banking.

Working at Allica Bank

At Allica Bank we want to ensure our employees have the right tools and environment in which to succeed in their role and in support of our customers.

Our employees are at the heart of everything we do, so our benefits are designed with you in mind:

• Full onboarding support and continued development opportunities

• Options for flexible working

• Regular social activities

• Pension contributions

• Discretionary bonus scheme

• Private health cover

• Life assurance

• Family friendly policies including enhanced Maternity & Paternity leave

Don’t tick every box?

Don’t worry if you don’t have all the skills or requirements listed on the job description. If you think you’ll be a good fit, we’d still love to hear from you!

Flexible working

We know the ‘9-to-5’ isn’t right for everyone. That’s why Allica Bank is fully committed to flexible and hybrid working. Please let us know what is best for you and, if we can, we will do our best to accommodate.

Diversity

We’re a diverse bunch here at Allica, with all kinds of experiences, backgrounds and lifestyles. Our openness and differences make us stronger, and we want everybody to feel comfortable bringing as much of themselves to work with them as they like.