Senior Software Engineer Waltham, MA

Xometry (NASDAQ: XMTR) powers the industries of today and tomorrow by connecting the people with big ideas to the manufacturers who can bring them to life. Xometry’s digital marketplace gives manufacturers the critical resources they need to grow their business while also making it easy for buyers at Fortune 1000 companies to tap into global manufacturing capacity.

Thomasnet, part of Xometry, is the industrial platform where millions of buyers find and source from North American manufacturers and suppliers.

We are seeking a Senior Software Engineer to join Thomas engineering. Thomas is moving from a traditional supplier directory to AI-assisted sourcing, where buyers describe what they need and the platform does the matching. You will build and maintain the systems behind that shift, from the product experiences buyers and suppliers use every day to the AI-powered features at the center of our strategy.

You will work closely with a product manager and peer and senior engineers.

• Hands-on technical leadership. Lead by example by actively coding, reviewing, and troubleshooting. Set good coding patterns and designs for the team.
• Lead projects end-to-end. Own the design and delivery of features within your team, from problem to production and largely independently, including the AI-powered capabilities at the center of our strategy: features that use LLMs, retrieval, and search, with the evaluations and guardrails that keep them accurate and safe.
• Mentorship and code review. Guide and mentor engineers on the team; do thorough code review and raise the bar for how others review.
• Operational excellence. Own testing and reliability for what you ship. Deliver software that meets customer expectations and business timelines.

• 6+ years of software development experience, focused on outcomes over output, with a habit of helping shape the team's direction rather than only building to spec.
• Strong full-stack skills that transfer to our stack: backend services in Type Script and Node.js with GraphQL APIs, a React and Next.js frontend, PostgreSQL, and search such as Open Search. Comparable experience in another modern stack counts just as much; prior experience with our exact tools is not required.
• Hands-on experience building AI-powered product features: LLM applications, retrieval-augmented generation, vector search, or search relevance. We hire AI-native engineers who build with these tools and judge their output rigorously, whatever the specific frameworks.
• Bonus points:
  
  experience with multimodal (image and text) embeddings and search, agent orchestration frameworks (e.g. Lang Graph, Lang Chain), and fine-tuning or adapting models for a domain.
• A fast learner with high agency who works fluently in an AI-native development environment and shares what they learn. We are all still learning how to build with AI, and we want people who help the team learn faster.
• Strong execution, debugging, and communication skills. Prioritizes unit and integration testing.
• E-commerce or marketplace product experience is a plus.

The estimated base salary range for new hires into this role is $170,000 – $195,000 annually + annual bonus, depending on factors such as job-related skills, relevant experience, and location. The total compensation package includes base, bonus, and equity. We also offer a competitive benefits package, including:

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Xometry is an equal opportunity employer. All applicants will be considered for employment without attention to race, color, religion, sex, sexual orientation, gender identity, national origin, veteran, or disability status.

For US based roles:
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