The 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.

This role will work across the full stack — building custom applications for attorneys and Professional Staff, establishing the engineering infrastructure that the team relies on (CI/CD, deployment pipelines, observability), and contributing to the design and implementation of AI-powered solutions. The Senior Software Engineer will collaborate closely with the Director of Engineering, data scientists, knowledge management professionals, and practice solutions teams to deliver tools that make a measurable difference in how the Firm operates.

This is a hands-on, high-autonomy role on a small team where every engineer has significant ownership over the systems they build.

JOB DUTIES & RESPONSIBILITIES:

Software Development & Architecture

• Design, develop, 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, bringing practical perspective on tradeoffs 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 — including establishing and maintaining component libraries and design system foundations as the team's product surface grows.

Infrastructure, Reliability & Observability

• 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.

• Ensure systems are reliable, secure, and aligned with Firmwide technology standards.

AI & Legal Technology Solutions

• 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 as needed — demoing tools, gathering feedback, and helping users get value from what the team builds.

Collaboration & Craft

• Evaluate and prototype new tools, frameworks, and approaches that could improve how the team builds — bring experiments that work to the rest of the team.

• Help establish the engineering culture of a new function — contribute to decisions about how the team works, not just what it builds.

EDUCATION:

• Bachelor's degree in Computer Science or related working experience.

SKILLS & EXPERIENCE:

Required

• 7+ years of experience in software engineering, 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.

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.

Salary Information

Simpson Thacher will not sponsor applicants for work visas for this position.