Principal Engineer (AI)

Location: Hybrid, London, with 2 days per week in the Central London office.

Company

hirify.global is the UK's largest online car-selling platform, connecting private sellers with more than 8,000 dealers through a technology-led marketplace.

What you will do

• Set technical strategy, architecture standards, engineering practices, and documentation norms across multiple product areas.
• Identify and resolve cross-cutting architectural risks, while evaluating what to build, buy, adopt, or retire using technical and commercial criteria.
• Own the engineering relationship with AWS, including architecture reviews, early-access programmes, service adoption decisions, and cost considerations.
• Raise standards for reliability, observability, security, SLOs, incident management, production readiness, and threat modelling.
• Lead adoption and evaluation of AI, LLMs, and agents for software engineering, including technical-debt modernisation and trustworthy output evaluation.
• Develop staff engineers and technical leads, and represent hirify.global at AWS summits, conferences, meetups, and internal forums.

Requirements

• 10+ years of software engineering experience, including several years operating at Staff or Principal level.
• Track record of setting technical direction across several teams or product areas and influencing company outcomes.
• Exceptional AWS expertise across serverless, containers, networking, identity, and data services at production scale.
• Experience evaluating platforms and services against structured technical and commercial criteria.
• Strong API and identity architecture experience with OAuth 2.0, OIDC, PKCE, JWT, and IAM patterns across multiple accounts.
• Experience setting observability and reliability standards and running serious incident-management practices.
• Ability to read or write code in most languages and follow requests from the browser through to the data layer.
• Experience developing senior engineers into technical leaders and raising the hiring bar.
• Practical experience building LLMs and agents in production, including evaluation and trustworthy output controls.
• Strong public-speaking record at conferences, summits, or large internal forums, with the ability to communicate technical arguments to engineers and executives.
• Strong technical writing skills across specifications, architecture decision records, and strategy documents.

Nice to have

• Curiosity about new tools and the judgement to identify which are worth adopting.
• Experience mentoring engineers, supporting technical reviews, or helping colleagues prepare public talks.

Culture & Benefits

• Hybrid work schedule with 2 days per week in the London office, plus regular social events, office drinks, and free snacks.
• Strong work-life balance and personal-development support, including a budget for books, courses, and conferences.
• Stock options and a pension scheme through NEST.
• Opt-in comprehensive BUPA health insurance, including dental care and fitness discounts.
• Cycle-to-work scheme, one paid volunteering day per year, and generous parental benefits including paid maternity and paternity leave and a workplace nursery scheme.