Senior Software Engineer, Content Agent

Sanity; Greater London; Hybrid; GBP 90,000 - 150,000; Full time

Benefits offered by this job

Health insurance

Stock options

Flexible work environment

Global, diverse team

Job summary

Sanity is hiring a Senior Engineer for Content Agent, part of the operations layer that turns content work into runnable tasks. You will build full‑stack features in TypeScript and React, work on MCP tools, agent loops, and system prompts, and improve reliability of live, production systems.

You’ll join a team shipping LLM-driven workflows with a focus on edge cases, user intent, and scalable architecture, collaborating closely with product and design.

Qualifications

• Strong TypeScript and React across the stack.
• Experience shipping LLM-based systems in production.
• Ability to design robust architectures for agent workflows.

Responsibilities

• Full-stack product work: React dashboards and APIs.
• Develop MCP tools and integrations for the agent.
• Design and refine agent orchestration and system prompts.
• Run evaluations to improve reliability in real usage.

Skills

TypeScript

React

APIs

LLMs

Systems thinking

Job description

We're hiring a senior engineer for Content Agent - Sanity's operations layer for structured content. It's the system that turns content work (bulk edits, audits, translation, publishing) into things an agent can actually run. It lives in Dashboard, Studio, Slack, and behind a headless API. If you've spent time on AI systems that have to hold up for real users, not just in a demo, read on.

At Sanity, we build an AI-powered content operating system that lets teams model, create, and automate content the way their business actually runs. SKIMS, Figma, Riot Games, Anthropic, COMPLEX, Nordstrom, and Morningbrew run their content operations on it.

Content Agent is the part of the product that understands structured content - schemas, references, field types, validation rules - and can be trusted to operate on it correctly. You'd be doing full-stack product work in TypeScript and React: MCP tools and integrations, agent orchestration, system prompts, evals to make the whole thing more reliable. Engineers on this team own their domain and work closely with product on what gets built next.

WHAT YOU'D BE DOING:

• Full-stack product work: React interfaces in Dashboards, APIs, backend services.
• MCP tools and integrations that extend what the agent can do.
• Agent loops: the orchestration logic that decides what the agent does, in what order, and when to bring a human in.
• System prompts. We treat these as real engineering artifacts, not a note at the top of a file.
• Evals and experiments to measure and improve reliability in real usage.
• GROQ, Sanity's content query language - using it to give the agent a deep understanding of structured content.
• Shaping what Content Agent becomes, with product and design. There's a lot of latitude here.

ABOUT YOU:

• Location: London, UK or Oslo, Norway (in-office 2–3 days/week)
• Strong TypeScript and React, comfortable across the stack (frontend, APIs, backend). You don't want to be boxed into one layer.
• You've shipped LLM-based systems in production. You know the hard part isn't getting a model to do something once; it's getting it to do the right thing for every user who shows up.
• You think in systems. Given a new agent capability, you think through user intent, edge cases, failure modes, and what that means for the architecture: what the agent knows, what tools it has, when it escalates.
• You write well and you care about why one phrasing works where another doesn't. An agent's instructions are prose running on a system that reads literally. Writing them well takes a feel for how language lands, not just what it says - who "you" refers to, what's implied versus explicit, how a sentence will actually be parsed.
• You're comfortable with probabilistic systems. Improving an LLM product means running experiments, designing evals, reading results statistically, and not chasing individual failures when the aggregate trend is what matters. You've moved past "it compiles or it doesn't."
• Real experience with, or real curiosity about, MCP, tool-use patterns, and agent architectures.
• You care about craft in code, in writing, and in the products you ship.

Nobody checks every box. We're especially interested in people from non-traditional backgrounds - writing, interaction design, liberal arts - who've built real engineering skills on top. Some of the best agent work we've seen comes from people who understand language and how people actually work, not just systems architecture. If this sounds like you, send something in.

WHAT WE CAN OFFER:

• A highly-skilled, inspiring, and supportive team
• Positive, flexible, and trust-based work environment that encourages long-term professional and personal growth
• A global, multi-culturally diverse group of colleagues and customers
• Comprehensive health plans and perks
• A healthy work-life balance that accommodates individual and family needs
• Competitive stock options program and location-based salary

WHO WE ARE:

Sanity.io http://Sanity.io is a modern, flexible content operating system that replaces rigid legacy content management systems. One of our big differentiators is treating content as data so that it can be stored in a single source of truth, but seamlessly adapted and personalized for any channel without extra effort. Forward-thinking companies choose Sanity because they can create tailored content authoring experiences, customized workflows, and content models that reflect their business.

Sanity recently raised an $85m Series C led by GP Bullhound and is also backed by leading investors like ICONIQ Growth, Threshold Ventures, Heavybit and Shopify, as well as founders of companies like Vercel, WPEngine, Twitter, Mux, Netlify and Heroku. This funding round has put Sanity in a strong position for accelerated growth in the coming years.

You can only build a great company with a great culture. Sanity is a 200+ person company with highly committed and …