Senior Applied AI Engineer: End-to-End AI Systems

Fresha; Greater London; Hybrid; GBP 120,000 - 150,000; Full time

Job summary

Fresha is seeking a Senior Applied AI Engineer for our London product team. You will join a cross-functional group building AI-powered features that customers interact with directly, including AI reception and related tooling.

The role blends senior backend engineering with applied AI work. You will own end-to-end delivery, design systems around the model, and ensure production quality and scalable performance in a hybrid office setting.

Qualifications

• 5+ years building and running backend services in production.
• Shipped a product on top of LLM APIs or agent frameworks your users rely on.
• Written evaluations for non-deterministic systems: test sets, graders, LLM-as-judge.
• Understanding retrieval, tool design and MCP; architecture matters more than prompts.
• Consider correctness, idempotency and system reliability when requests arrive twice or timeouts occur.

Responsibilities

• Own AI features end to end: design, build, evaluate, ship and support them in production.
• Build the system around the model: services, tools and integrations to enable real work (availability, bookings, payments).
• Prove it works: create evals, graders and production checks to measure impact and reliability.
• Engineer the context: determine what the model knows and which tools it can call.
• Work in real time: balance latency, cost and quality under tight SLAs.
• Learn from real conversations: analyze transcripts and telemetry to drive next changes.
• Collaborate with Product, Design, Support and other engineers from first talk through release.
• Shape our architecture, AI practices and engineering practices with senior judgment.

Skills

Backend services

LLMs / AI agents

Evaluations

Context & tool design

Distributed systems

Cost & latency

Product sense

AI in workflow

Backend languages

Job description

Fresha is seeking a Senior Applied AI Engineer for our London product team. You will join a cross-functional group building AI-powered features that customers interact with directly, including AI reception and related tooling.

The role blends senior backend engineering with applied AI work. You will own end-to-end delivery, design systems around the model, and ensure production quality and scalable performance in a hybrid office setting.