Senior Full-Stack Engineer

Simulations Plus stands as a global leader in model-informed and AI-accelerated drug development. We create value for our clients by accelerating the discovery, development, and commercialization of pharmaceuticals and other products through innovative science-based software and consulting solutions.

Leadership truly cares about maintaining a positive culture and employee well-being. We offer fully remote work, flexible schedules, and generous vacation policy along with affordable health coverage, annual bonus, and more! Check out how much our employees love working here: https://www.comparably.com/companies/simulations-plus.

The Senior Full-Stack Engineer is a versatile contributor, part of a small department whose charter spans both web/SaaS and AI/agents products. The role will ship features across the full stack — backend, frontend, and LLM-integrated surfaces — wherever the team's most pressing implementation work lands in a given cycle. It's a high-variety role for an engineer who wants to build real depth across web platform and applied-AI engineering, on a deliberately lean team that's growing quickly and intentionally.

Department: Product and Technology 

Internal Grade: 10

Direct Reports: No

Status: Exempt

Location: Remote 

Job Responsibilities:

• Feature Delivery Across the Stack
  • Own features end-to-end across Node.js and Express backends and React/Tailwind frontends
  • Build the APIs, UI, and data flows behind real customer-facing functionality
  • Contribute to the data, auth, and service patterns the platform builds on
• AI Feature Integration
  • Integrate LLM-powered functionality into product surfaces, working alongside the team's AI lead
  • Wire frontends to LLM and MCP endpoints; handle streaming, errors, and degraded states gracefully
  • Contribute to evals, fixtures, and tooling that support the AI side of the team
• Team Impact
  • Bring full-stack range to a team that values flexibility across backend, frontend, and AI
  • Contribute to code reviews, documentation, and the team's shared engineering practices
  • Apply AI coding tools effectively as part of daily engineering workflow
• Other Duties as Assigned 

Required Qualifications:

• 3+ years of professional software engineering experience, with shipped full-stack work in production
• Proficiency in JavaScript or TypeScript across Node.js backend and React frontend
• Practical experience with document or NoSQL databases such as MongoDB
• Comfort building and consuming REST APIs and JSON contracts
• Genuine interest in agents, MCP, and applied AI, and the drive to build real expertise in those areas
• Fluency using AI coding tools (Claude, Cursor, Copilot) in daily workflow 

Preferred Qualifications:

• Familiarity with Anthropic, OpenAI, or other LLM provider SDKs
• Exposure to MCP, agent frameworks, or LLM-integrated product features
• Experience with cloud infrastructure (AWS preferred) and CI/CD pipelines
• Experience in regulated-software environments (SOC 2, HIPAA, GxP, 21 CFR Part 11) or life-sciences SaaS
• Familiarity with Passport, OAuth, OIDC, or comparable auth patterns

Education: 

• Bachelor's degree in computer science, engineering, or related field preferred
• Relevant technical certifications welcomed

Come join the happiest employees in the industry by visiting www.simulations-plus.com/career-center and apply today!