Senior Software Engineer

Senior Software Engineer – Knowledge & Innovation (K&I) Senior Software Engineer will be a core member of the engineering team within the Knowledge & Innovation (K&I) department, responsible for designing, building, and operating the software systems that power the firm’s legal technology and AI initiatives. This role combines strong full‑stack development skills with a focus on infrastructure, reliability, and the foundational systems that enable the team to ship and maintain production‑grade tools at scale. Responsibilities Develop, architect and maintain custom software solutions supporting Knowledge & Innovation initiatives, including AI‑powered tools, internal platforms, and integrations with existing firm systems. Contribute to architectural decisions in partnership with the Director of Engineering, providing practical perspective on trade‑offs between speed, reliability, and maintainability. Build and extend integrations across SaaS platforms, internal systems, data sources, and AI/LLM services used in legal workflows. Develop frontend experiences that are polished, consistent, and designed with care, establishing and maintaining component libraries and design system foundations as the team’s product surface grows. Own and evolve the team’s engineering infrastructure: CI/CD pipelines, deployment automation, infrastructure‑as‑code, and development environment tooling. Establish observability practices—monitoring, logging, alerting—so the team has confidence in the health and behavior of production systems. Partner with IT to navigate the firm’s infrastructure environment, coordinating on security protocols, cloud resources, and deployment targets, ensuring systems are reliable, secure, and aligned with firm‑wide technology standards. Contribute to the development of AI‑powered tools—including retrieval‑augmented systems, document analysis platforms, search tools, and workflow automation—working alongside product, data scientists, and the broader K&I team. Help translate complex legal and business requirements into practical, well‑engineered software, collaborating with attorneys, knowledge management professionals, and practice solutions managers. Support adoption and iteration by interfacing directly with legal staff, demoing tools, gathering feedback, and helping users get value from what the team builds. Evaluate and prototype new tools, frameworks, and approaches that could improve how the team builds, and bring experiments that work to the rest of the team. Contribute to the engineering culture of a new function—helping establish decisions about how the team works. Qualifications 7+ years of software engineering experience with demonstrated progression in scope and responsibility. Strong full‑stack skills across JavaScript/TypeScript, React, Node.js, and Python. Experience with cloud infrastructure (AWS and/or Azure), infrastructure‑as‑code (Terraform/Bicep), and CI/CD pipelines (GitHub Actions or equivalent). Practical experience with AI/LLM integration in production systems, or strong aptitude and interest in developing it. Experience with agentic coding tools (e.g., Claude Code, Cursor, Codex). Comfort working directly with non‑technical stakeholders—able to demo work, gather feedback, and explain technical decisions clearly. Preferred: experience in legal technology, professional services, or other highly regulated environments. Experience establishing observability and monitoring practices (logging, alerting, dashboards) for production systems. Familiarity with design systems, component libraries, or frontend architecture patterns at the systems level. Experience integrating and extending enterprise SaaS platforms. Education Bachelor’s degree in Computer Science or related field, or equivalent work experience. Key Competencies Strong engineering judgment—knows when to build and what not to build. Comfort with ambiguity—can make progress with incomplete information and adjust as context develops. Pragmatic craftsmanship—cares about the quality and polish of what ships, without over‑engineering. Curiosity and initiative—brings ideas, experiments, and improvements without being asked. Clear communication with both technical and non‑technical audiences. Additional Information Salary: $180,000 to $210,000 (NY only). This position is exempt, meaning it is not overtime pay eligible. Simpson Thacher will not sponsor applicants for work visas. The firm prohibits discrimination or harassment based on protected characteristics. This policy applies to all aspects of employment. #J-18808-Ljbffr