Principal Engineer, CoCounsel

Thomson Reuters

Principal Software Engineer at Thomson Reuters developing AI solutions for legal workflows. Collaborating with engineers and researchers to deliver reliable, user-facing AI services.

Posted 6/29/2026full-timeEagan • Minnesota, Missouri, New York, Texas • 🇺🇸 United StatesLead💰 $158,900 - $295,100 per yearWebsite

Tech Stack

Tools & technologies

AWSCloudDistributed SystemsPostgresPython

About the role

Key responsibilities & impact

Participate in shaping the company’s AI platform and patterns
Work at real production scale: Build and evolve systems that operate over millions of documents, complex and ever-changing law, privileged client data, and thousands of concurrent AI interactions from professionals doing time-sensitive work
Join a tight group of senior engineers and researchers shipping quickly, with direct access to product leadership and customers
Lead and/or design initiatives that cut across AI, product, identity, and infrastructure
Mentor staff and senior engineers, raising the bar on AI integration practices, system design, code quality, and security across the org
Help define and lead the platform integration strategy across new and existing Thomson Reuters legal systems
Define how autonomous agents act on a user’s behalf safely
Partner with security, platform, and compliance teams on multi-tenancy isolation, data residency, privilege protection, and the audit trails that legal and government customers require
Design for high-throughput, low-latency AI workloads: caching, queuing, rate-limiting, model failover, and cost/performance trade-offs
Establish and refine SLOs, observability, and incident response for AI systems that must be correct, auditable, and trustworthy in professional legal workflows

Requirements

What you’ll need

Bachelor’s Degree in Computer Science, Computer Engineering, a related field, or equivalent experience
Demonstrated experience building with AI – LLMs, agents, and retrieval – and a strong point of view on what “AI-native” software should look like
Proven track record owning large, complex projects end-to-end: architecture, execution, rollout, and long-term operation
Deep Python expertise and experience with production systems using frameworks like FastAPI (or similar), relational databases (PostgreSQL or equivalent), and a major cloud provider (AWS preferred)
Strong background in distributed systems: data modeling, API contracts, observability, resilience patterns, and performance tuning under load
Hands-on experience with identity and access management – designing or integrating authentication and authorization at scale (SSO, SAML, OIDC, OAuth 2.0, RBAC/ABAC, token/session management, or comparable IAM systems)
Excellent communication skills and the ability to partner with product, design, security, and ML teams in a fast-moving environment

Benefits

Comp & perks

Health insurance
401(k) matching
Flexible work hours
Paid time off
Remote work options
Flexible vacation
Two company-wide Mental Health Days off
Access to the Headspace app
Retirement savings
Tuition reimbursement
Employee incentive programs
Resources for mental, physical, and financial wellbeing
Employee Assistance Program
Group Legal Identity Theft Protection benefit paid 100% by employee
Commuter benefits
Adoption & Surrogacy Assistance
Access to Employee Stock Purchase Plan

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills & Tools

AI-Native Software DevelopmentLarge Language Models (LLMs)FastAPI FrameworkPostgreSQLCloud Computing (AWS)Data ModelingAPI ContractsPerformance TuningAuthentication and AuthorizationIncident Response

Soft Skills

Excellent CommunicationMentoring