Senior Software Engineer

Overview of the Role

The CoCounsel Legal Integrations team within Thomson Reuters is seeking Senior Software Engineers to join the Content Tools team. The role focuses on building purpose‑built APIs that provide AI agents precise, governed access to Thomson Reuters’ proprietary legal content across international jurisdictions. You will own tools from the first commit through production deployment and operation, ensuring high reliability, accuracy, and speed.

• Design, develop, and own Content Tools end‑to‑end—APIs and retrieval components that enable agents to query legal content through well‑documented, contract‑driven interfaces.
• Ship API‑first tools with versioned contracts, schemas, and metadata so consuming teams can use them self‑service.
• Build retrieval components that respect latency budgets, shape result payloads, and maintain clear tool boundaries for agent orchestrators.
• Collaborate with research scientists to build and tune retrieval and search on the Vespa search platform, improving relevance and ranking quality.
• Practice spec‑driven development: write acceptance criteria, create evaluation datasets, build eval suites, and establish CI gates that verify every change.
• Work within the core stack—Python, FastAPI, Pydantic on AWS; use Git Hub Actions for CI, Datadog for observability, and expose tools via the Claude Agent SDK and MCP.
• Participate in on‑call rotation, own incident triage, root‑cause analysis, runbooks, and post‑mortems; treat deployment friction as a bug and pursue constant delivery.
• Instrument components with logging, metrics, and distributed tracing; capture tool‑invocation sequences to diagnose failures.
• Define and monitor SLOs for owned tools, treating fast, safe delivery as part of the job.
• Lead technical direction for tools, break product and customer requirements into actionable work, and provide feasibility input.
• Serve as the subject‑matter expert for at least one content domain or tool family; mentor junior engineers through code reviews and pairing.
• Collaborate with R&D (TR Labs) to integrate new retrieval capabilities responsibly.
• Build relationships with CoCounsel Engineering and product owners; document decisions in ADRs and communicate clearly to all audiences.
• Champion ethical AI and secure, responsible engineering in every deliverable.

• Bachelor’s or Master’s degree in Computer Science, Engineering, or related field.
• 5+ years of software engineering experience designing, developing, and testing production backend, API, or data‑infrastructure systems.
• Mastery of Python and strong fundamentals in API design and rigorous testing (unit, integration, evaluation).
• Solid knowledge of distributed systems, failure modes of services, queues, and data stores.
• Proficiency with AWS services, Datadog, and CI/CD practices (blue/green, canary deployments).
• Operational ownership: on‑call participation, architectural documentation, post‑mortems, and a philosophy that building and operating are inseparable.
• Fluency with AI‑assisted development tools; majority of code written with AI assistance without sacrificing quality.
• Excellent communication of technical concepts to both technical and non‑technical audiences.

• Information‑retrieval fundamentals (precision/recall, hybrid search, ranking) and their impact on downstream product quality.
• Experience building APIs or tools for agentic AI systems, including MCP or similar protocols.
• Background in legal technology, knowledge management, or other high‑stakes information domains where source attribution and accuracy matter.
• Familiarity with Vespa, Open Search, or Elasticsearch for query writing, index design, or cluster operation.
• Integration of AI services—embedding APIs, re‑ranking models, RAG retrieval—with robust error handling.
• Knowledge of API gateways (e.g., Apigee) and securing, versioning, and exposing content APIs.
• Experience with deterministic eval suites, gold data gating in CI, and red‑team prompt injection testing tools.
• Understanding of infrastructure‑as‑code (Terraform) and container orchestration (ECS or Kubernetes) with CI/CD pipeline optimization.

• Hybrid work model with flexible…