LLM / SLM Full-Stack Developer

Hitachi Digital LLC; Birmingham; On-site; GBP 60,000 - 80,000; Full time

Job summary

A leading digital transformation company in Birmingham seeks a LLM Full-Stack Developer to design and operate production AI applications. Responsibilities include building responsive web UIs and implementing ensemble strategies across LLMs. The ideal candidate will have over 6 years of experience in full-stack development, proficiency in Python and TypeScript, and a focus on Agentic AI workflows. Competitive benefits and a commitment to diversity in the workplace are part of the offering.

Benefits

Industry-leading benefits

Flexible work arrangements

Support for holistic health and wellbeing

Qualifications

• 6+ years of full-stack development experience.
• 3+ years of experience building LLM applications.
• Proficiency in Python and TypeScript/Node.js.

Responsibilities

• Design, build, and operate production AI applications.
• Implement ensemble strategies across LLMs and SLMs.
• Build responsive, accessible web UIs for AI features.

Skills

Full-stack development

LLM applications

Python

TypeScript/Node.js

React

Agentic AI

Ensemble strategies

Education

Bachelor’s/Master’s in CS, AI/ML, or related field

Tools

GCP services

Vector DBs

RAG

Job description

We’re Hitachi Digital, a company at the forefront of digital transformation and the fastest growing division of Hitachi Group. We’re crucial to the company’s strategy and ambition to become a premier global player in the massive and fast-moving digital transformation market.

Our group companies, including GlobalLogic, Hitachi Digital Services, Hitachi Vantara and more, offer comprehensive services that span the entire digital lifecycle, from initial idea to full-scale operation and the infrastructure to run it on. Hitachi Digital represents One Hitachi, integrating domain knowledge and digital capabilities, and harnessing the power of the entire portfolio of services, technologies, and partnerships, to accelerate synergy creation and make real-world impact for our customers and society as a whole.

Imagine the sheer breadth of talent it takes to unleash a digital future. We don’t expect you to ‘fit’ every requirement – your life experience, character, perspective, and passion for achieving great things in the world are equally as important to us.

About Us

Hitachi Digital builds secure, scalable AI applications for global OpCos, with a focus on Agentic AI and enterprise governance. We leverage GCP services (Vertex AI, Agent Workspace), robust data foundations, and model guardrails to deliver business outcomes at scale.

Role Overview

We’re seeking a LLM Full‑Stack Developer who can design, build, and operate production AI applications that combine front‑end product craftsmanship with backend/LLMOps rigor. You will implement ensemble strategies across LLMs and SLMs (small language models), develop Agentic AI workflows, and integrate RAG, evaluation, and guardrails into full‑stack experiences. Gemini Enterprise experience is nice to have; strong GCP/Vertex AI skills are expected.

Key Responsibilities

• Product & Front-End
• Build responsive, accessible web UIs for AI features (chat, copilot sidebars, inline recommendations).
• Implement human-in-the-loop UX and telemetry hooks.
• Implement ensemble LLM/SLM pipelines with fallback/guarded execution.
• Expose secure APIs and integrate with enterprise systems.
• Agentic AI & Orchestration
• Design multi-agent workflows with tool-use policies and memory strategies.
• Use Vertex AI Agent Builder/Workspace for orchestration.
• Quality, Safety & Observability
• Implement guardrails, explainability, and audit logs.
• Performance & Cost
• Optimize prompts, retrieval, caching, batching, autoscaling.

Required Qualifications

• Bachelor’s/Master’s in CS, AI/ML, or related field.
• 6+ years full-stack development; 3+ years building LLM applications.
• Experience with ensemble LLM/SLM approaches.
• Hands‑on with Agentic AI patterns.
• Proficiency in Python and TypeScript/Node.js.
• Expertise with vector DBs, embeddings, RAG.
• UI experience with React or similar.

Preferred Qualifications

• Experience with Gemini Enterprise / Agent Workspace.
• Familiarity with LangChain/Graph and knowledge graphs.
• Exposure to SLM distillation/fine‑tuning.
• Google Cloud certifications.
• Product mindset with strong UX quality bar.
• Systems thinking across data/models/agents.
• Security & compliance awareness.
• Strong communication across global teams.

Success Metrics (first 6–12 months)

• Launch 2+ LLM features with measurable impact.
• Achieve >20–30% response quality or latency improvements.
• Establish evaluation dashboards and telemetry.
• Document guardrails and explainability to governance standards.

What You’ll Work With

• Vector DBs, embeddings, RAG, optional knowledge graphs.
• Python, Node.js/TypeScript, React, CI/CD, observability tools.

About us

We’re a global, 1000‑strong, diverse team of professional experts, promoting and delivering Social Innovation through our One Hitachi initiative (OT x IT x Product) and working on projects that have a real‑world impact. We’re curious, passionate and empowered, blending our legacy of 110 years of innovation with our shaping our future. Here you’re not just another employee; you’re part of a tradition of excellence and a community working towards creating a digital future.

Fostering innovation through diverse perspectives

Hitachi is a global company operating across a wide range of industries and regions. One of the things that sets Hitachi apart is the diversity of our business and people, which drives our innovation and growth.

We are committed to building an inclusive culture based on mutual respect and merit‑based systems. We believe that when people feel valued, heard, and safe to express themselves, they do their best work.

How we look after you

We help take care of your today and tomorrow with industry‑leading benefits, support, and services that look after your holistic health and wellbeing. We’re also champions of life balance and offer flexible arrangements that work for you (role and location dependent). We’re always looking for new ways of working that bring out our best, which leads to unexpected ideas. So here, you’ll experience a sense of belonging, and discover autonomy, freedom, and ownership as you work alongside talented people you enjoy sharing knowledge with.

We’re proud to say we’re an equal opportunity employer and welcome all applicants for employment without attention to race, colour, religion, sex, sexual orientation, gender identity, national origin, veteran, age, disability status or any other protected characteristic. Should you need reasonable accommodations during the recruitment process, please let us know so that we can do our best to set you up for success.