Principal Engineer - ONESOURCE Tax

## Principal Engineer - ONESOURCE Income Tax Apply:
Hybrid:
United States of America, Frisco, Texas:
Full time:
Posted Today:
End Date:
November 30, 2026 (30+ days left to apply):
JREQ
203889
** Job Description
** Are you an engineering leader who likes solving hard technical problems and also understands the business behind them? Thomson Reuters is looking for a
** Principal Software Engineer
** to join the
** ONESOURCE Income Tax
** team. Our portfolio includes
** Income Tax, Estimated Payments, Data Query and Reporting, Work papers, and General Ledger Manager Classic**. These are tier-one products that large US corporations rely on to file their taxes, and our customers have high expectations.

Our applications are built on **.NET, Angular, SQL Server, and PostgreSQL**. Data Query, our data warehousing solution, runs on
** Google Cloud Platform (GCP)
** with a
** Looker
* * front end. Our products are delivered through the ONESOURCE platform, hosted on
** AWS and GCP**, and customers also use them through our APIs. We have started building with AI, including our own
** MCP servers**, and we are moving toward
** agentic AI**.In this role, you will set the long-term technical vision for our current platforms and the applications we build next. You will set engineering standards, lead secure design practices, and help the team through SOC audits and third-party security testing. You will also represent engineering to Product, Security, the Product Management Office, and senior leadership. This is a strategic, high-impact role.

You will be seen as a technical role model, both inside the organization and in the wider industry.  
** Key Responsibilities**
* ** Technical vision and strategy:
** Set the long-term technical vision for the ONESOURCE Income Tax portfolio. Design solutions that support long-term business goals and contribute to strategy across the business unit.
* ** Architecture and standards:
** Understand our current legacy systems in depth. Define the architecture patterns, standards, and best practices for future applications.
* ** Agentic AI:
** Help design the architecture for AI agents and expand the team's existing MCP server capabilities. Find places where AI and other technologies can change how the business works.
* ** Security and compliance:
** Lead the team's approach to secure design so applications pass third-party penetration tests and meet our high standards for Snyk vulnerability scanning. Set up patterns and processes for the team to follow instead of fixing issues yourself. Help the team through SOC audits and related controls.
* ** Cloud and infrastructure:
** Guide the design, maintenance, and modernization of applications and infrastructure on AWS and GCP.
* ** Complex, high-risk initiatives:
** Lead complex projects with significant risk that affect a whole sub-business unit, function, or major product. Run development reviews and spot and fix weaknesses in existing designs.
* ** Technology selection:
** Lead the selection, evaluation, and rollout of new technologies and tools, and promote their adoption across teams.
* ** Stakeholder partnership:
** Work closely with Product Owners, ISRM/Security, the Product Management Office, and senior leadership. Represent the engineering team and negotiate solutions between key people.
* ** Communication:
** Present complex technical ideas and technology strategy to executives, technical managers, peers, and developers.
* ** Mentorship and culture:
** Mentor and coach Senior and Lead engineers. Help individual contributors understand proposed technical changes and strengthen the wider engineering culture.
* *
* Cross-functional collaboration:

** Start and take part in work across business units. Look for shared opportunities and recommend improvements to processes, products, or services.
* ** Innovation:
** Encourage practical innovation and contribute to standards and patents. Develop new concepts, services, and technologies that meet current and future customer needs.
* ** Project partnership:
** Work with project managers to include technical status in project reports. Lead or support several projects at once.  
** Required Qualifications
*** Bachelor's degree in Computer Science, Engineering, or a related field, or equivalent experience
* 10+ years of software engineering experience, including significant time in senior, lead, or principal-level technical leadership roles
* Strong experience with the Microsoft stack (**.NET / C#**),
** Angular**,
** Microsoft SQL Server**, and
**…