Staff Software Engineer, Fullstack, Foundry Group

We’re seeking a Staff Software Engineer to join a new team at HubSpot, Foundry.

Where You’ll Work

• Location: Seattle or San Francisco
• Alternate location: Remote / Hybrid
• Travel: Approximately monthly to Seattle/SF for in-person team or AI industry events.

About the Role

As a Staff Software Engineer on the Foundry team, you will build emerging products that solve real GTM jobs for small businesses - fast.

You will build and experiment at the edge of what AI makes possible, putting early versions in front of real founders to find what works, and scaling what resonates into products that earn a place in every SMB’s stack.

You’ll ship working product to real users weekly, work directly with AI models and APIs, and make architectural decisions that prioritize learning velocity over perfection.

This is a full-stack, AI-native building role. You’ll design systems that combine deterministic workflows with agentic reasoning, build products that handle unstructured data and messy real-world inputs, and iterate based on what customers actually do. You should be as comfortable prompting a model as you are writing a database migration.

About Foundry

HubSpot Foundry is a small, focused team with a singular mission: win the next generation of small businesses by building where small businesses start. The Foundry team operates autonomously, with a builder mindset, weekly shipping, and founder-level ownership.

We are building and experimenting at the edge of what AI makes possible, putting early versions in front of real founders to find what works, and scaling what resonates into products that earn a place in every SMB’s stack.

We build modules that solve single go-to-market jobs exceptionally well, deliver value in minutes, and expand naturally into the full HubSpot platform. Foundry focuses on critical go-to-market use cases - including creating agent teammates that help teams get discovered in the AI era, find and qualify prospects, and automate human tasks.

What We Look for Across All Foundry Roles

Foundry is for builders who want to move fast, learn from customers, and thrives in ambiguity to get things done. Regardless of your role, you should bring:

• AI-native fluency. You use AI daily, not as a novelty, but as infrastructure. You have a deep understanding of what models can and can’t do, where they break, and how to design around those limits. You’ve built with LLMs, agents, or AI-powered products and have strong intuitions about product building.
• A hacker spirit. You prototype before you plan. You’d rather test an idea with real users this week than spend a month getting alignment. You love solving puzzles and are comfortable writing code, hacking together demos, or getting your hands dirty with data.
• First-principles thinking. You navigate ambiguity by going back to what’s true, not what’s been done before. You find simple, easy-to-understand solutions to complex problems and you’re willing to throw out playbooks when the situation demands it.
• Deep user empathy for small businesses. You understand what it’s like to wear multiple hats, to be the same person qualifying leads, running sales calls, and managing the website. You are passionate about building for small businesses or founder, and helping them grow.
• Intellectual curiosity without ego. You’re comfortable asking questions and learning independently. You think creatively about the risks and benefits of new technologies, moving beyond past checklists. You’d rather be right than be the one who was right.
• Founder-level ownership. You don’t wait for permission. You experiment, you ship product, you get things done. You get energy from ambiguity and rapid change. You’ve built something from zero before or you’ve been the person who made something work when nobody had the answer.

As a Staff Engineer, you’ll do many things— and you likely already have experience doing some of them in the past. We are looking for people who:

• Experience building and shipping LLM-powered products in production, including prompt design, tool/function calling, structured outputs, and retrieval (RAG). Familiarity with agent patterns and multi-step workflows is important. Experience working with or building shared platforms, SDKs, or developer infrastructure is a plus. Bonus for experience with evaluation systems (e.g., prompt testing, datasets, scoring), observability/tracing, and optimizing for latency, cost, and reliability in real-world AI systems.
• Have a thirst for technical challenges implemented within secure, compliant systems. We leverage technologies such as Java, HBase, Vitess, Kafka, GraphQL and Dropwizard. We’re not necessarily looking for someone who is an expert in a specific technology, but someone who is well-versed in engineering principles and eager to leverage them when running toward the problems that we face.
• Proven track record of owning and delivering high-impact products end-to-end, driving outcomes that meaningfully move the business forward. Staff Engineers are one of the most senior individual contributors at HubSpot; they are leaders that continually strive to raise the bar for the engineering organization as a whole, and are expected to help drive the product vision forward via strong collaboration skills and hands-on coding.
• Stay deeply hands-on across the stack while leading by example, working directly with customers and partners to ship, learn, and iterate quickly. Drive alignment through outcomes, not process, and move the product forward with urgency and ownership.
• Have a track record of building and scaling solutions that drive meaningful business impact, with a mindset of challenging the status quo and creating step-change improvements rather than incremental gains.
• Set clear direction and drive execution on the company’s most critical bets, ensuring they translate into real customer and business impact.
• Raise the bar for the team through strong technical judgment, clear thinking, and high-quality execution, helping others operate at a higher level through example and direct collaboration.
• Demonstrate strong, pragmatic decision-making and problem-solving, consistently balancing speed and quality. Know when to build for immediate impact versus long-term scale, avoiding over-engineering while ensuring solutions are reliable enough to learn, iterate, and grow from.
• Exhibit an enthusiasm for building reliable, scalable systems.
• Can guide teams beyond the status quo; we need engineers who lead us beyond what we have, and towards what we can build, while building a shared notion of how to get there.
• Embodies our engineering team values.

Additional Responsibilities

• Build and ship end-to-end product capabilities (e.g., agentic teammates, lead qualification, AEO, meeting support) from zero to production quickly, delivering meaningful customer value in weekly, high-velocity iterations.
• Design and implement AI-powered features: agent orchestration, NLP-driven workflow creation, multi-step reasoning chains, enrichment pipelines, and real-time inference
• Build systems that balance deterministic reliability with agentic flexibility - knowing when a workflow should be predictable and when it should reason
• Own the full stack: frontend experiences, backend services, data pipelines, AI integrations, and infrastructure
• Implement human-in-the-loop patterns, confidence thresholds, fallback behaviors, and guardrails that keep AI products trustworthy at scale
• Prototype rapidly. Test ideas with real users before polishing. Use AI tooling (Cursor, Claude Code, Copilot) to move at startup speed
• Instrument everything. Build for observability so the team can learn from real user behavior and model performance
• Collaborate directly with PM and Design to shape what gets built - you’re not handed specs, you’re co-creating the product