Senior Software Engineer II, Flywheel Foundations
HubSpot
Flywheel Context (Foundations) Team
UK - we're open to fully remote, hybrid or office based - whatever works best for you!
Role Summary
HubSpot is building the next generation of AI-powered experiences across our go-to-market platform. We’re hiring a Senior Software Engineer II to join the Flywheel Context team - a foundational group responsible for building the data and context layer that powers intelligent AI assistants and agents across HubSpot.
This is a backend-leaning, data-intensive role focused on building durable production systems. You’ll design and ship the infrastructure that enables AI systems to access relevant customer context, process large volumes of CRM data, and deliver high-quality outputs at scale.
If you’re excited about building foundational platforms that unlock smarter AI across an entire product ecosystem, this role is for you.
What You’ll Do
- Design, build, and operate backend services that power context retrieval, enrichment, and insight generation across HubSpot’s platform.
- Build systems for storing, processing, and retrieving high-volume GTM data (e.g., contact history, CRM activity, behavioral signals).
- Develop scalable data processing and streaming solutions to support AI-driven use cases.
- Create reusable platform capabilities and APIs that enable other product teams to build smarter AI assistants and agents.
- Contribute to evaluation and quality frameworks to ensure context accuracy, reliability, and performance.
- Collaborate closely with platform teams and downstream product engineering teams to integrate capabilities into real customer experiences.
- Own end-to-end delivery: architecture, implementation, observability, performance, and iteration in production environments.
What We’re Looking For:
- Strong track record shipping production backend systems as a senior engineer, with ownership from design through operation.
- Professional experience building maintainable, scalable backend services (Java preferred).
- Strong data background and experience working with large datasets, data pipelines, and data-intensive systems.
- Experience building or integrating AI/ML-adjacent systems in production (e.g., retrieval pipelines, embeddings, ranking systems, model-backed services, or similar).
- Experience operating systems at scale, including performance optimization and reliability considerations.
- Strong engineering fundamentals: system design, testing, debugging, observability, and operational excellence.
- Product mindset - comfortable collaborating cross-functionally and building platform capabilities used by other engineering teams.
Nice to Have
- Experience with search, retrieval, ranking, or relevance systems.
- Familiarity with RAG architectures, vector search, or hybrid retrieval approaches.
- Experience with streaming technologies or event-driven architectures.
- Cloud-native development experience (e.g., Kubernetes, AWS/GCP).
- Some frontend experience or willingness to contribute across the stack when needed.
- Python experience.
Why This Role Matters
AI systems are only as good as the context they can access. This team is responsible for unlocking HubSpot’s greatest competitive advantage: the depth and richness of customer data across the platform.
Your work will directly impact how intelligent and reliable HubSpot’s AI agents become and enabling a true 360° understanding of customers and accelerate AI innovation across Flywheel.
We know the confidence gap and impostor syndrome can get in the way of meeting spectacular candidates, so please don’t hesitate to apply — we’d love to hear from you.
If you need accommodations or assistance due to a disability, please reach out to us using this form.
At HubSpot, we value both flexibility and connection. Whether you’re a Remote employee or work from the Office, we want you to start your journey here by building strong connections with your team and peers. If you are joining our Engineering team, you will be required to attend a regional HubSpot office for in-person onboarding. If you join our broader Product team, you’ll also attend other in-person events, such as your Product Group Summit and other gatherings, to continue building on those connections.
If you require an accommodation due to travel limitations or other reasons, please inform your recruiter during the hiring process. We are committed to supporting candidates who may need alternative arrangements
Massachusetts Applicants: It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability.
Germany Applicants: (m/f/d) - link to HubSpot's Career Diversity page here.
India Applicants: link to HubSpot India's equal opportunity policy here.
About HubSpot
HubSpot (NYSE: HUBS) is an AI-powered customer platform with all the software, integrations, and resources customers need to connect marketing, sales, and service. HubSpot's connected platform enables businesses to grow faster by focusing on what matters most: customers.
At HubSpot, bold is our baseline. Our employees around the globe move fast, stay customer-obsessed, and win together. Our culture is grounded in four commitments: Solve for the Customer, Be Bold, Learn Fast, Align, Adapt & Go!, and Deliver with HEART. These commitments shape how we work, lead, and grow.
We’re building a company where people can do their best work. We focus on brilliant work, not badge swipes. By combining clarity, ownership, and trust, we create space for big thinking and meaningful progress. And we know that when our employees grow, our customers do too.
Recognized globally for our award-winning culture by Comparably, Glassdoor, Fortune, and more, HubSpot is headquartered in Cambridge, MA, with employees and offices around the world.
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