Senior AI Engineer

Antal International; Greater London; Hybrid; GBP 90,000 - 140,000; Full time

Job summary

Antal International is seeking a Senior AI Engineer to lead NLP/LLM initiatives in a legal tech SaaS platform. You will own end‑to‑end AI features, from model design to production deployment, with a focus on secure, scalable document processing workflows.

The role combines hands‑on development with collaboration across engineering, product and QA, reporting to the CTO in a hybrid/remote UK setup. You will optimise latency, cost and compliance while integrating AI into enterprise workflows.

Qualifications

• 5+ years delivering NLP/ML models in production SaaS.
• Strong Python, API integration, and model deployment.
• Experience with LLMs, transformers, and AI infra.

Responsibilities

• Lead AI feature development in the core product.
• Design and build ML models for document parsing, search, summarisation.
• Integrate LLMs into workflows with guardrails and monitoring.
• Optimise model serving for latency and cost on AWS.
• Build data pipelines for training and evaluation.

Skills

Python

NLP

LLMs

API development

AWS

Model deployment

Tools

OpenSearch

Redis

PostgreSQL

Hugging Face

PyTorch

TensorFlow

AWS ECS/Lambda

Job description

Senior AI Engineer (NLP / LLM): Legal Tech SaaS

Location: UK, hybrid/remote

Reports to: CTO (Permanent role - No Visa Sponsorship)

The company

An early-stage legal tech SaaS business building workflow automation for a specialist area of transactional law. Its platform streamlines the drafting and management of complex legal documentation for law firms and institutional clients in financial services, replacing slow, manual, document-heavy processes.

The product is live, has clear product-market fit and is gaining traction with customers. The roadmap is ambitious and AI features are a core part of it, which is why this role exists.

The engineering team is lean and senior. People are expected to take ownership, stay close to customers and choose simple solutions over complex ones. The team works in Scrum squads with strong CI/CD, infrastructure as code and security-first practices. This role reports directly to the CTO, so your work has a direct and visible effect on the product and on revenue.

The role

You will lead the development of AI features in the core product. This is a hands‑on role.

• Design and build ML models for document parsing, search, classification and summarisation
• Integrate LLMs into product workflows with guardrails, evaluation and monitoring
• Optimise model serving and inference for latency and cost on AWS (ECS, Lambda, S3)
• Build data pipelines for training and evaluation (PostgreSQL, Redis, OpenSearch)
• Work with engineering, product and QA to ship AI features that meet enterprise security and compliance requirements

Requirements

• 5+ years as an AI/ML engineer delivering NLP and ML models into production SaaS
• Strong Python, including building APIs and integrating models into applications
• NLP frameworks such as Hugging Face Transformers, PyTorch, spaCy or TensorFlow
• AWS and distributed systems
• Data pipelines and orchestration for model training and evaluation

Nice to have

• Legal tech or another document-heavy domain
• Vector databases and semantic search (OpenSearch, Pinecone, FAISS)
• Explainability and compliance work on deployed AI
• Knows React or TypeScript

Right to work

No visa sponsorship is available. Applicants must already hold the full right to work in the UK.