Senior Software Engineer

Senior Software Engineer - Content Tools

Content Tools
* CoCounsel Legal Integrations

The CoCounsel Legal Integrations team within Thomson Reuters is seeking Senior Software Engineers to join the Content Tools team in building purpose-built APIs that give AI agents precise, governed access to TR's proprietary legal content across various international jurisdictions. These tools are the bridge between TR's authoritative content and the AI products, such as CoCounsel Legal, that depend on them, and they carry high stakes - every result must be accurate and grounded in TR's authoritative content.

This is a full-ownership engineering role on a team that designs, develops, tests, deploys, and operates the production content APIs that agentic workflows rely on.

The team's operating principles are non-negotiable: you own what you build end-to-end, from the first commit to the production dashboard. You ship to production constantly, and you treat delivery friction as an engineering problem to solve, not a fact of life. You use AI-assisted development as a primary tool, with the expectation that the majority of code is written with AI assistance.

And you practice verified spec-driven development: you write the acceptance criteria and utilize evaluation datasets that specify a tool's behavior before you build it, and that eval suite gates every change in CI. Senior Engineers own a tool, subsystem, or content domain end-to-end, hold design‑decision authority within their scope, serve as the team's subject‑matter expert in at least one area, and mentor more junior colleagues.

This is a role for someone who takes genuine pride in the quality, reliability, and pace of their work.

As a Senior Software Engineer, you will:

• Design, develop, and own Content Tools end‑to‑end: the APIs and retrieval components that let agents query TR legal content through precise, well‑documented, contract‑driven interfaces, for example, jurisdiction‑specific tools spanning legal content across multiple geographies
• Build API‑first: every tool ships with a versioned contract, schema, and ownership metadata so consuming teams and agent developers can use it self‑service, without needing to ask you how it works
• Design retrieval components for agentic use: respect explicit latency budgets across multi‑hop chains, shape result payloads with token economy in mind, and build clean tool boundaries that give agent orchestrators predictable interfaces
• Build and tune the retrieval and search behind the content tools in collaboration with our research scientists from TR Labs - improving relevance and ranking quality on our Vespa based search platform.
• Practice verified spec‑driven development: write the acceptance criteria and utilize evaluation datasets that define a tool's behavior before you implement it - the eval is the spec - then build the eval suite, gold data, and CI gates that verify every change
• Work in the team's core stack - Python, FastAPI, and Pydantic on AWS, search in Vespa, with CI in Git Hub Actions and observability in Datadog - building agent tools on the Claude Agent SDK and exposing them to agents over MCP (Model Context Protocol), and contributing to the shared libraries, generators, and patterns that help the whole team build tools correctly

• Participate in the on‑call rotation and take end‑to‑end ownership of incidents in your scope - triage, root‑cause analysis, clear communication, and post‑mortems that surface systemic fixes; you built it, you run it. Write and improve the runbooks for your areas.
• Treat delivery friction as a bug: a slow deploy, a flaky test, or a painful local workflow is a problem worth fixing, because the team's ability to ship constantly depends on every engineer pushing back on friction
• Instrument your components with structured logging, metrics, and distributed tracing; for agentic retrieval paths, capture tool‑invocation sequences and per‑hop inputs so non‑deterministic failures can be diagnosed and reproduced
• Define and monitor SLOs for the tools you own, and treat fast, safe delivery as part of the job rather than a…