Principal Engineer - Global Consumer Brand, Millions of Loyalty Member - Competitive Base + Bonus + Benefits

The opportunity A household-name UK consumer brand is hiring a Principal Engineer to sit at the centre of its consumer digital estate. The estate includes a native mobile app, websites, a loyalty programme used by millions, and click and collect. The role is neither an architect nor a developer. It is the layer in between. Architects set the direction, delivery teams build it, and this person makes sure what gets designed can actually be built, and is built properly. You will understand how every part of the platform fits together (services, APIs, SaaS platforms, libraries, tooling) well enough to spot problems before they reach production. The technology function is growing towards 200 people, including a nearshore engineering centre scaling from 70 to 100 engineers. You will work across teams rather than inside one, and be the person they rely on for sound technical judgement. This role is 3 days on site in one of their offices in Hertfordshire - A car allowance is also provided. What you'll do

• Make designs buildable. Work with Architecture at the design stage and with engineering leads during delivery, so that solutions are realistic, well understood and deliverable.
• Own key platforms technically. Take technical ownership of core consumer platforms such as the loyalty platform and the mobile app, and understand them end to end.
• Shape build decisions. Be closely involved in which technologies are adopted, how things are built, and what delivery timelines are realistic.
• Connect the stack. Understand how backend services, APIs, mobile and web front ends, and third-party platforms (customer engagement, promotions and loyalty, headless CMS) work together, and resolve problems where they meet.
• Raise engineering standards. Make sure the right engineering metrics, productivity tooling and quality practices are in place, and use evidence to improve how teams deliver.
• Reduce risk. Spot technical debt, fragile integrations and delivery risks early, and turn them into clear, prioritised action.
• Work across boundaries. Partner with Product, Architecture, Security, Service and external partners, and give credible technical challenge where it's needed.
• Strengthen the team. Share knowledge across UK and nearshore teams and reduce reliance on individual experts. This is not a hands-on coding role. You won't be writing production code day to day, but you will need a deep, practical understanding of the full stack. What we're looking for
• Experience level. A very senior individual contributor: Principal, Staff or Lead Engineer, or equivalent. You have deliberately chosen the technical path over people management.
• Delivery background. You came up through software delivery, ideally in mobile, web or platform engineering, and have since broadened to understand the whole stack.
• Polyglot understanding. You are comfortable across several technologies at a high level, such as .NET, Azure (with some AWS), Web, native iOS and Android, and SaaS platforms for customer engagement, promotions and content.
• The bridging skill. You have a track record of turning architectural intent into something teams can deliver, and of spotting when a design won't work in practice.
• Sound judgement. You can weigh trade-offs, challenge assumptions and make clear recommendations on technology and approach.
• Delivery focus. You care about metrics, tooling, quality and getting things into production.
• A doer, not an evangelist. You are pragmatic and get things done without the big talk. Nice to have
• Experience with loyalty, CRM or e-commerce platforms
• Experience with platforms like Braze, Talon.One or Sanity, or close equivalents
• A background in a consumer-facing, high-traffic environment
• Experience working with nearshore or third-party engineering teams
• A degree in Computer Science, Maths, Physics or another analytical subject This role probably isn't for you if…
• you want to spend most of your time coding
• you're an enterprise or solution architect who works mainly at the diagram level
• your background is purely infrastructure or cloud
• you're looking for a people-management role The role:
• Principal Engineer, Consumer Digital
• Hertfordshire, hybrid (60% in office)
• Permanent Package
• Competitive base
• Car allowance
• Bonus: 15% on target, up to 30%
• Pension matched up to 10%
• Private healthcare
• Share incentive plan
• Life insurance and income protection
• 33 days' holiday
• 35-hour week
• Generous staff discounts