Senior Software Engineer

About the role

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.

Responsibilities

• Content Tool Engineering
  • 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 specify a tool’s behavior before you build it, and that eval suite gates every change in CI
• Reliability & Operations
  • 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 trade-off against reliability
  • Use AI-assisted development tools fluently across your workflow — generation, review, testing, debugging, — and model effective patterns for the team
• Technical Leadership & Collaboration
  • Take technical direction for your tools with design-decision authority within your scope; break product and customer requirements into work the team can execute, and provide technical input on feasibility rather than only receiving tasks
  • Serve as the team’s go-to subject-matter expert for at least one content domain or tool family; provide domain-expert review on high-risk PRs and mentor more junior engineers through code review, pairing, and coaching
  • Build working relationships with CoCounsel Engineering and product owners
  • Capture decisions in writing through project-level ADRs, and communicate clearly to both technical and non-technical audiences
  • Champion ethical AI and secure, responsible engineering across your work

Requirements

• Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field
• 5+ years of software engineering experience designing, developing, and testing production backend, API, or data-infrastructure systems, with demonstrated end-to-end ownership of features and components
• Mastery of Python and strong fundamentals, including API design and a rigorous testing discipline (unit, integration, and evaluation) — you write high-quality production code and test everything you ship
• Solid distributed-systems knowledge: you understand the failure modes of services, queues, and datastores and design systems resilient to them
• Proficiency with AWS cloud services, Datadog and CI/CD practices (Blue/Green, Canary deployments); you ship small PRs frequently with fast feedback loops
• Demonstrated operational ownership: on-call participation, architectural documentation and decision records, post-mortems, and a clear philosophy that building and operating are inseparable
• Fluency with AI-assisted development tools as a primary part of your workflow — you write the majority of your code with AI assistance and use it to accelerate delivery without sacrificing quality, and you own the outcome regardless of how the code was produced
• Prominent ability to communicate technical concepts clearly to technical and non-technical audiences, including design documents and component documentation

Qualifications

• Working knowledge of information-retrieval fundamentals (precision/recall trade-offs, hybrid search, ranking)
• Experience building tools or APIs for agentic AI systems, including tool protocols such as MCP (Model Context Protocol) or similar
• Background in legal technology, knowledge management, or other high-stakes information domains where source attribution, accuracy, and entitlement matter
• Familiarity with search and retrieval engines (Vespa, OpenSearch, Elasticsearch) at the level of writing queries, designing indexes, or operating clusters
• Experience integrating AI services — embedding APIs, re-ranking models, RAG-supported retrieval — with error handling and fallback strategies in production
• Familiarity with API gateways (such as Apigee) and how a content API is secured, versioned, and exposed to consumers
• Experience with agent and retrieval evaluation: deterministic eval suites and gold data gated in CI, red-teaming for prompt injection (e.g., Promptfoo), and tracing for LLM workflows (e.g., Langfuse)
• Working understanding of infrastructure-as-code (Terraform) and container orchestration (ECS or Kubernetes), with the ability to configure and optimize CI/CD pipelines

Skills

• Python
• FastAPI
• Pydantic
• AWS cloud services
• Datadog
• CI/CD practices (Blue/Green, Canary deployments)
• Structured logging, metrics, and distributed tracing
• API gateways (such as Apigee)
• Agent and retrieval evaluation
• Infrastructure-as-code (Terraform)
• Container orchestration (ECS or Kubernetes)

Benefits

• Hybrid Work Model
• Flexibility & Work-Life Balance
• Career Development and Growth
• Industry Competitive Benefits
• Culture
• Social Impact
• Making a Real-World Impact

Pay

Competitive salary commensurate with experience

Schedule

Flexible work schedule, typically 2-3 days in the office per week