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Motorway is the UK's largest online car-selling platform, connecting private sellers with over 8,000 dealers nationwide. Founded in 2017 and backed by leading technology investors (£143M Series C), the company operates a technology-led marketplace handling hundreds of vehicle transactions daily.
You will join a 70-person engineering organization as Principal Engineer, reporting to the Director of Engineering. This is a broad, company-wide technical leadership role spanning multiple product areas and all engineering specialties. Your decisions will shape architecture, technology adoption, and engineering practices across the organization.
Key responsibilities include:
- Setting technical strategy across multiple product areas and making the commercial case to leadership with data
- Identifying and resolving cross-cutting architectural risks before they block scale
- Establishing engineering standards, architectural patterns, documentation norms, and writing precision for both human engineers and AI agents
- Raising the bar on reliability, observability, security, SLO philosophy, incident management, production readiness, and threat modeling
- Leading Motorway's adoption of AI for software engineering: monitoring LLM usage, evaluating latest models, and modernizing technical debt through AI agents
- Developing staff engineers and technical leads to multiply leadership capacity
- Owning the AWS relationship on the engineering side: architecture reviews with solution architects, early access programs, and service adoption decisions
- Representing Motorway publicly at AWS summits, conferences, and meetups; raising internal standards for how engineers present work
Motorway has been an early adopter of GenAI for software engineering and wants to maintain that reputation. You'll define what good looks like when domain depth, AI-enabled breadth, and rigorous evaluation work together. Engineers have access to latest models through Kiro, and you'll guide their effective use.
The role is hybrid: 2 days per week in the Central London office.
REQUIREMENTS:
- Ten years or more in software engineering, with several years at Staff or Principal level
- Track record of setting technical direction across multiple teams/product areas where your decisions changed company outcomes
- Exceptional AWS expertise (wide and deep): designed, operated, and managed costs for serverless, containers, networking, identity, and data services at production scale; can hold your own with AWS solution architects
- Judgment to evaluate new platforms and services against structured technical and commercial criteria; ability to say no
- Strong grounding in API and identity architecture: OAuth 2.0, OIDC, PKCE, JWT, and IAM patterns across multiple accounts
- Experience setting observability and reliability standards; running incident practice that teams take seriously
- Comfort across the stack: can read/write code in most languages; can follow a request from browser through to data layer
- Record of developing senior engineers into technical leaders and raising hiring bar in your discipline
- Practical production experience building with LLMs and agents, including evaluation and trustworthiness methods
- Strong public speaker with conference, summit, or large internal forum presentations; can make technical arguments land with engineers or executives
- Writing that holds up under scrutiny: specs, architecture decision records, strategy documents that others can act on without meetings
IDEAL TRAITS:
- Create clarity when no obvious technical path exists
- Challenge status quo with evidence and worked alternatives; patience to bring people along
- Advocate for simplest architecture meeting requirements; lived experience with long-term costs of alternatives
- Carry pattern library of production failures and over-engineered systems; use it to prevent expensive mistakes
- Want the stage, not tolerate it; comfortable in keynotes and team demos
- Enjoy making engineers around you better through mentoring, review, or helping with first public talks
- Stay curious about new tools and honest about which are worth adopting
