Full-Stack Engineer at a Startup — Equity & Mentorship

Ultrasonium; Woburn (MA); On-site; USD 120,000 - 180,000; Full time

Benefits offered by this job

Stock options or equity

Direct mentorship from founding team

Ownership of real services

Lean on-site environment

Job summary

Ultrasonium is seeking a versatile software engineer to build and maintain full-stack features, primarily with Next.js and Python APIs, while supporting embedded firmware and collaborating with electrical, controls, mechanical and process teams.

You will work directly with the founding team from implementation to working deployment, documenting learnings and ensuring service reliability and scalability in a lean on-site environment.

Qualifications

• Bachelor's degree or equivalent project experience in CS or related field.
• Hands-on full-stack web development with deployed projects.
• Experience with Next.js and Python, building or consuming HTTP APIs.
• Familiarity with Git, Linux, and deploying services to cloud/server env.

Responsibilities

• Build and maintain full-stack web features, primarily in Next.js.
• Develop Python APIs with FastAPI and MCP servers with FastMCP.
• Provision and operate deployment environments and health checks.
• Support embedded firmware interfacing with sensors and hardware teams.
• Document learnings and keep internal tools and runbooks current.
• Write tests and ensure reliability of services after deployment.

Skills

Full-stack development

Next.js experience

Python

HTTP APIs

Git & Linux

Education

Bachelor's degree in CS or related

Tools

Docker

CI/CD

Cloud deployment

Job description

Ultrasonium is seeking a versatile software engineer to build and maintain full-stack features, primarily with Next.js and Python APIs, while supporting embedded firmware and collaborating with electrical, controls, mechanical and process teams.

You will work directly with the founding team from implementation to working deployment, documenting learnings and ensuring service reliability and scalability in a lean on-site environment.