Production AI Agent Engineer – Scale, Customer Impact, Equity

Hackajob Ltd; City of Westminster; On-site; GBP 90,000 - 110,000; Full time

Job summary

Sierra is building a platform that helps businesses create more human customer experiences with AI. The team operates as an in-person company with offices in SF and expanding globally, including London.

We seek engineers who can design production-grade AI agents, own the development lifecycle, and collaborate with enterprise customers to transform operations at scale. Ideal candidates have a track record building AI/LLM systems in production, a founder mindset, and strong communication across

Qualifications

• Experience building and scaling end-to-end production systems.
• Strong technical problem-solving skills in fast-changing, ambiguous environments.
• A builder and tinkerer mindset with high agency and creativity to overcome obstacles and ship.
• Comfort working directly with customers to understand their needs and solve real-world problems.
• Excellent communication skills across technical and non-technical audiences.
• Experience building or deploying AI/LLM systems in production.
• Experience as a founder or founding engineer, with the ability to balance craft, ownership, and speed.
• Familiarity with tools that power todays AI agents, including eval frameworks, agent tooling, RAG pipelines, and prompt engineering.
• Prior experience with React, TypeScript, and/or Go.
• Previous roles interfacing with customers or leading technical projects with external stakeholders.

Responsibilities

• Design and deliver production-grade AI agents that are highly performant, reliable, and intuitive.
• Own the Agent Development Life Cycle from initial pilot through deployment and continuous iteration.
• Build, tune, and evolve AI agents in production environments.
• Work directly with leaders at large enterprises to understand business challenges and build AI agents that transform how they operate at scale.
• Partner with cutting-edge startups in London to embed AI agents across their business stack.
• Surface unmet needs from customer work, prototype new tools and features, and collaborate with research, product, and platform to shape the future of AI agent development and our product.
• Design and build AI agents for large telecommunications and media companies that outperform human agents in managing subscription churn.
• Develop AI agents for complex customer interactions such as troubleshooting broken devices and personalizing product recommendations.
• Create generalizable AI agent frameworks tailored for industry-specific use cases.
• Facilitate design partnerships for new product initiatives, including new agent architectures, self-service capabilities, and generative agent development.
• Experiment with the latest voice models and integrate them at scale for enterprise-grade customers.

Skills

Experience building and scaling end-to

Technical problem-solving in ambiguous

Builder mindset

Customer engagement

Communication skills

AI/LLM production experience

Founder mindset

AI agent tooling familiarity

React/TypeScript/Go

Customer-facing/project leadership

Tools

React

TypeScript

Go

Job description

Sierra is building a platform that helps businesses create more human customer experiences with AI. The team operates as an in-person company with offices in SF and expanding globally, including London.

We seek engineers who can design production-grade AI agents, own the development lifecycle, and collaborate with enterprise customers to transform operations at scale. Ideal candidates have a track record building AI/LLM systems in production, a founder mindset, and strong communication across