Lead Software Engineer – Python/React

Lead Product Engineer (Full Stack), Materia AI This role is heavily backend focused (roughly 70% backend / 30% frontend). We are specifically looking for engineers who have built and shipped real products end-to-end , not just contributed small features within large organizations. Strong preference for candidates with: Hands-on ownership building production products from 0→1 Python backend depth (FastAPI/Django/APIs/microservices) Scalable distributed systems Product engineering mindset Customer-facing feature ownership React/TypeScript capability to support full-stack delivery Startup or greenfield experience Engineers who can independently design, build, and deliver systems in production Frontend experience is required, but this is NOT a frontend-heavy/UI-focused role . We need backend-first engineers who can also contribute across the stack when needed. == Are you excited about building AI-driven software that redefines how professionals work? Have you built scalable Python backend systems that power customer-facing products? Join a dynamic and highly skilled team at Thomson Reuters, where we combine the agility and innovation of a startup with the stability and resources of a global leader. As a Lead Product Engineer, you will play a pivotal role in designing and building the backend services and APIs that power AI-driven accounting workflows, while contributing across the full stack to rapidly iterate on features, drive user engagement, and optimize outcomes through data-driven experimentation. Innovate in a Startup-Like Environment Be part of a fast-moving, forward-thinking group that is creating AI-driven software for accounting professionals. You'll join a team of top engineers and AI developers, leveraging cutting-edge technology to build intelligent and scalable systems. This role is for the CoCounsel for Accounting team, formed from the recent acquisition of the startup Materia. Create Impactful, AI-Driven Experiences Lead backend-driven full stack initiatives — from Python-based AI services and APIs to the React interfaces that bring them to life. You'll architect and implement complete features that deliver generative AI capabilities, alongside core product systems that streamline and modernize accounting workflows. Building the intelligent backend systems and connecting them to polished user experiences, your work will shape how thousands of accounting professionals leverage AI and modern software in their everyday workflows. Collaborate Across Functions Work closely with product managers, designers, and AI specialists to deliver elegant, high-performance features. Your ability to translate complex requirements into robust solutions — scalable APIs and services complemented by polished interfaces — will be key to our product's success. About the Role: In this role as a Lead Product Engineer , you will work on a backend-leaning full stack team building customer-facing product features. This role is a backend-leaning full stack position . The team is looking for engineers with strong Python backend experience who have worked on customer-facing product systems . While the role involves both backend and frontend development, the primary focus is building scalable backend services and APIs that power product features. Candidates should have strong experience building backend systems using Python frameworks such as FastAPI, Flask, or Django , and be comfortable designing APIs and services that operate at scale. On the frontend side, the team works with modern frameworks including React, Next.js, and TypeScript , so candidates should be comfortable contributing across the stack and connecting frontend interfaces to backend services. The ideal candidate has a product mindset , enjoys shipping features end-to-end , and works closely with product managers, designers, and engineering teams to deliver high-quality user experiences. While the role is full stack, deep backend expertise in Python is the priority , with the ability to contribute to frontend development when needed. Develop Design, build, and maintain the backend services powering generative AI products such as Conversations, Accounting Research, Ready to Advise, and Workspaces Develop robust backend systems with Python, FastAPI, Pydantic, and cloud infrastructure, including API design, data modeling, system architecture, and AI service integration Own complex, 6+ month projects from beginning to end, including ideation, working with cross-functional partners in product and UX, testing, launching, measuring impact, and iteration Contribute to front-end development using Next.js, TypeScript, and Tailwind CSS to connect interfaces to backend services Identify bottlenecks and optimize for speed, scalability, and responsiveness across the full stack Collaborate & Lead Serve as a technical leader for backend-driven projects through making prioritization decisions, scoping out timelines, guiding the work of engineers, and collaborating with cross-functional partners Contribute to technical design decisions across the stack, including architecture, API design, and system integration patterns Set and enforce team-wide frameworks, best practices, and code quality standards for both backend and frontend development Mentor and develop junior and mid-level engineers through code reviews, technical guidance, and career development Establish and maintain high engineering standards for code quality, testing, and architecture Lead by example in technical excellence, delivery accountability, and collaborative problem-solving Champion Product Quality Drive high standards for backend reliability, API design, and system performance Apply strong product sensibilities to deliver polished, accessible, and user-centric experiences Proactively collect feedback from end users and internal stakeholders, and iterate accordingly About You: You are a fit for a Lead Product Engineer (Full Stack) if your background includes: We're looking for engineers with strong Python backend experience and solid full-stack capability. You should be a backend-strong engineer who is comfortable working across the stack — someone who can architect robust services and APIs and also contribute effectively to the front end when needed. Experience & Skills 7+ years building web applications at scale, with deep experience in backend development and practical front-end skills (we're looking for backend-strong engineers who can work across the full stack) Strong proficiency in Python and backend frameworks (FastAPI, Flask, or Django), with experience designing APIs and services that operate at scale Comfortable contributing to front-end development with React, Next.js, and TypeScript Appreciation for good UI/UX and product design — you care about the end-user experience even when your primary focus is backend systems Self-driven with a proactive approach to problem-solving and prioritization Experience building new products or features from 0 to 1 or from ideation to release Excellent debugging skills and an eye for performance optimization Strong leadership and cross-functional collaboration abilities Bonus Points Bachelor's degree in Computer Science or related field Experience working in a startup or similar fast-paced setting Experience building AI-native products, chatbot interfaces, or API-driven platforms Familiarity with large language models (LLMs), AI agent design, and/or prompt engineering Experience with cloud infrastructure, event-driven architectures, or observability tooling Opinionated about testing methodologies, A/B testing, and safe rollouts #LI-TH1 What’s in it For You? Hybrid Work Model: We’ve adopted a flexible hybrid working environment (2-3 days a week in the office depending on the role) for our office-based roles while delivering a seamless experience that is digitally and physically connected. Flexibility & Work-Life Balance: Flex My Way is a set of supportive workplace policies designed to help