Staff Software Engineer, AI Serving (AI Infrastructure) — HubSpot, London Full Time

If you are looking for staff software engineer jobs London, HubSpot is currently hiring a Staff Software Engineer for its AI Serving team within AI Infrastructure. This full-time, flex-role is based in London, United Kingdom, and the position appears on HubSpot’s official careers site with the internal reference POS-22139. For engineers interested in AI engineer jobs London and the broader UK tech market, this role offers direct involvement in building the inference infrastructure that powers AI capabilities across HubSpot’s platform.

Quick job overview

About the employer

HubSpot (NYSE: HUBS) is an AI-powered customer platform that provides marketing, sales, and service software for businesses of all sizes. Headquartered in Cambridge, Massachusetts, the company employs thousands of people globally and operates offices in Dublin, London, Berlin, Tokyo, Singapore, and Sydney. HubSpot’s platform is used by over 238,000 customers across more than 135 countries. The company has been recognised for its workplace culture by Comparably, Glassdoor, and Fortune, and describes its working philosophy as “bold is baseline.” HubSpot’s London office serves as a key engineering hub, and the company regularly lists HubSpot careers London openings across infrastructure, product, and AI teams. For other tech roles in the UK capital, browse our UK jobs category.

What this role involves

This position sits within the AI Infrastructure group, specifically on the AI Serving team. The team is responsible for the systems that deploy, serve, and operate machine learning models at production scale across HubSpot’s entire platform. If you have been searching for AI infrastructure engineer jobs UK, this role covers the full lifecycle of model serving — from writing the code that powers inference, to guiding architecture decisions that affect cost and reliability. Your core responsibilities include:

• Writing and shipping production code that directly powers AI capabilities across HubSpot’s platform, serving as a crucial building block for user and business impact at scale.
• Leading the evolution of HubSpot’s model serving and inference infrastructure, improving reliability, scalability, and cost-efficiency across the AI stack.
• Setting technical direction for how HubSpot deploys and operates machine learning models at scale, guiding architecture decisions, cost optimisation, and developer experience improvements.
• Working closely with Machine Learning Engineers, Product Software Engineers, and other Infrastructure teams to streamline model deployment and serving workflows end to end.
• Building and maintaining core Python libraries while gaining deep exposure to a wide range of HubSpot infrastructure systems.

Required skills and qualifications

HubSpot does not list rigid degree requirements for this role. Instead, the emphasis is on demonstrated ability and track record. Based on the official listing, the following are expected:

• A proven track record of directly contributing to and leading infrastructure projects at scale, ideally in serving, deployment, or platform engineering.
• Ability to work collaboratively with a team to solve problems, transfer knowledge, and develop overall platform architecture.
• Ability to work effectively across teams, driving technical initiatives spanning multiple groups within AI Infrastructure and beyond.
• Comfort with ambiguity — capable of taking on broad, cross-team problems and driving them to resolution without waiting for every detail to be specified.
• Coaching and mentorship experience, supporting the growth of more junior engineers on the team.

Engineers applying for staff software engineer jobs London should also be comfortable with Python and Java, as the technical stack for this role centres on these languages. Experience with ML model serving frameworks (such as TensorFlow Serving, Triton Inference Server, or similar tools) is highly relevant. For candidates looking to strengthen their CV before applying, our international resume format guide covers how to present infrastructure and AI experience effectively.

Salary, benefits, and relocation support

HubSpot has not listed a specific salary for this role on its careers page. According to HubSpot’s careers information, the company offers competitive compensation, equity, and benefits. Details on salary, bonuses, or relocation packages would be discussed during the hiring process. Applicants should confirm any compensation-related questions directly with HubSpot’s recruitment team.

HubSpot’s standard benefits for UK-based employees typically include private medical insurance, life insurance, an employee stock purchase plan, unlimited vacation policy, and a home office stipend for remote workers. However, specific benefit packages vary by role and level, so candidates should verify details during the interview process.

Work permit / visa note

HubSpot’s application form explicitly asks candidates whether they currently hold legal work authorisation for the United Kingdom and whether they will require HubSpot’s support to maintain that authorisation now or in the future. This suggests the company may consider sponsorship on a case-by-case basis, but no blanket guarantee of visa sponsorship is stated. For engineers exploring software engineer jobs London visa sponsorship, it is worth noting that HubSpot’s willingness to discuss work authorisation sets it apart from employers that do not engage with sponsorship at all. Candidates who require work authorisation support should discuss this directly with HubSpot’s recruitment team during the application process. For a complete overview of the UK work visa system, read our UK Skilled Worker Visa 2026 guide.

Who this role may suit

• Senior or staff-level software engineers with experience building and operating ML model serving or inference infrastructure at scale.
• Engineers comfortable with Python and Java who want to work on AI infrastructure that directly supports production machine learning workloads.
• Professionals based in or willing to relocate to London, or those already authorised to work in the United Kingdom, who prefer a flexible work arrangement.
• Engineers who enjoy mentoring others and driving cross-team technical initiatives rather than working in isolation.

If you are comparing this opportunity with other staff software engineer jobs London, consider that HubSpot’s flex work model and its explicit engagement with visa questions make it a strong option for international candidates. You can also explore other IT and technology jobs on JobsRivo for similar roles across the UK and Europe.

How to apply officially

Applicants should apply directly through HubSpot’s official careers page. The listing for this role is available at hubspot.com/careers/jobs/7606988. Only applications submitted through this official channel will be considered by HubSpot’s recruiting team. The application form includes questions about work authorisation and location, so candidates should have this information ready.

Required documents

• A current CV or resume.
• HubSpot’s online application form, which includes fields for work authorisation status and location eligibility.
• No cover letter is explicitly requested, but applicants may include one as part of their submission.

Before submitting your application, review our interview questions guide for international jobs to prepare for potential conversations with HubSpot’s recruiting team.

Frequently asked questions

Below are answers to common questions about this specific role, based on the information available on HubSpot’s official careers listing.

Is this a remote role?

HubSpot classifies this as a “flex” role, meaning the successful candidate can choose to work from the office, work remotely, or adopt a hybrid arrangement within the United Kingdom. This flexibility is subject to HubSpot’s internal policies and team needs. If you are specifically interested in remote working arrangements, our remote jobs abroad guide compares freelancing versus full-time digital nomad options.

Does HubSpot provide visa sponsorship for this role?

HubSpot’s application asks whether a candidate needs employer support for work authorisation, which suggests that sponsorship may be possible on a case-by-case basis. However, no explicit guarantee of visa sponsorship is stated in the job listing. Candidates should discuss their specific situation with HubSpot’s recruitment team. You can also read our visa sponsorship jobs guide for a broader understanding of how employer sponsorship works.

What is the salary range for this position?

Not specified by the employer. HubSpot typically shares compensation details during the interview process rather than posting them on the job listing. For context on UK software engineering salaries, the UK government’s UK Visas and Immigration pages publish minimum salary thresholds for skilled worker routes.

What programming languages are used in this role?

According to the job listing, the primary technical stack involves Python and Java. The role involves building and maintaining core Python libraries and working with model serving infrastructure.

How can applicants verify this role is still open?

Visit HubSpot’s careers page for this listing. If the page is live and accepting applications, the role is still open. If the listing has been removed or marked as closed, the position is no longer available.

What other similar roles are available on JobsRivo?

JobsRivo lists several related positions in the UK and European tech sector, including a Backend Engineer role at Stripe Dublin and a Data & AI Governance Architect position at Booking.com Amsterdam. Browse all IT and technology jobs for the full selection.

Relevant resources

• Interview Questions for International Jobs 2026 — expert-crafted answers for global roles
• Resume for Jobs Abroad 2026 — international CV format and writing guide
• UK Skilled Worker Visa 2026 Guide — requirements and application process
• Work Culture Abroad 2026 — understanding UK and international workplace norms
• Remote Jobs Abroad Guide — freelancing vs full-time digital nomad comparison
• Visa Sponsorship Jobs Guide — how employer visa sponsorship works
• High-Income Skills for Visa Sponsorship — skills that increase your chances of employer support

Disclaimer

JobsRivo is an independent job listing portal and is not the employer. Applicants should apply only through the official employer website. JobsRivo does not charge fees, process visas, or guarantee job offers.

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