Junior Software Developer jobs in United Kingdom

This role can be Office/Hybrid/Remote based within the UK

HubSpot is at the forefront of empowering businesses with cutting-edge AI. We are seeking a Staff Software Engineer with a passion for infrastructure and developer experience to join our AI Serving team. The AI Serving team owns model inference and serving infrastructure end-to-end, ensuring AI models are reliably deployed, scaled, observed, and cost-efficient across all hublets and environments, while serving as the home for modern Python at HubSpot.

The team owns the serving frameworks and libraries that power synchronous, asynchronous, and offline inference, along with model deployment pipelines, autoscaling, and GPU/CPU resource management. The roadmap focuses on improving the reliability and efficiency of batch inference, strengthening model observability, and scaling AI infrastructure cost-effectively. The team also serves as the home for core Python libraries and tooling across HubSpot.

As a Staff Software Engineer on the AI Serving team you will:

• Write and ship production code that directly powers AI capabilities across HubSpot, a crucial building block for user and business impact at scale
• Lead the evolution of our model serving and inference infrastructure, improving reliability, scalability, and cost-efficiency
• Set technical direction for how HubSpot deploys and operates ML models at scale, guiding decisions on architecture, cost optimization, and developer experience
• Work closely with Machine Learning Engineers, Product Software Engineers, and other Infrastructure teams to streamline model deployment and serving
• Gain deep exposure to a wide range of HubSpot infrastructure systems through building and maintaining core Python libraries, an excellent opportunity to learn how HubSpot operates under the hood
• Collaborate with HubSpotters across the company in engineering, product, design, research, marketing, sales, etc., gaining exposure to how HubSpot works as a business
• Be empowered to show up as your authentic self and choose a work style and location where you can do your best work, whether that’s at home, in an office, or a blend of the two

We’re not just looking for engineers with many years of experience. We’re looking for engineers who show unique excellence, leadership, and the ability to elevate those around them.

We work with Python and Java primarily, but experience with specific technologies is secondary to strong programming fundamentals. Check out our engineering blog to learn more.

What we’d like to see:

• A proven track record of directly contributing to and leading infrastructure projects at scale, ideally in serving, deployment, or platform engineering
• The ability to work collaboratively with the team to solve problems, transfer knowledge, and develop overall platform architecture
• The ability to work effectively across teams, driving technical initiatives spanning multiple groups within AI Infrastructure and beyond
• Comfort with ambiguity: you can take on broad, cross-team problems and drive them to resolution without waiting for every detail to be specified
• Coaching and mentorship experience
• A track record in partnering successfully with recruiting to build remarkable engineering teams
• Bonus: Python expertise. Experience with Python tooling, libraries, and developer experience is a strong plus, given the team’s role in stewarding Python across AI workloads at HubSpot

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.

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.

Explore more:

• HubSpot Careers
• Life at HubSpot on Instagram

HubSpot may use AI to help screen or assess candidates, but all hiring decisions are always human. More information can be found here. By submitting your application, you agree that HubSpot may collect your personal data for recruiting, global organization planning, and related purposes. Refer to HubSpot’s Recruiting Privacy Notice for details on data processing and your rights.

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