Principal Software Engineer - Software Architecture

Imagine what you could do here. At Apple, new ideas have a way of becoming extraordinary products, services, and customer experiences very quickly. You bring passion and dedication to your job and there's no telling what you could accomplish. Apple is in search of an experienced Principal Software Engineer to join the Central Marketing's Marketing Enablement team in London to drive technical architecture vision for its marketing products. This is a deeply hands-on, high-impact role: you will work across portfolio of software products leading architecture discussions to decisions, establishing architecture and design standards while contributing to software development.

Our Principal Engineers are technical leaders who shape how software is built across a portfolio rather than within a single product. You will own the cross-product architectural view understanding how our products fit together, where the boundaries and dependencies sit, how information moves between them, and where duplication or fragility is accumulating and be able to articulate this to stakeholders. From that view you will define a target architecture and a roadmap to reach it, setting the agenda for consolidation, modernisation, and structural improvement across existing products, and sequencing that work so it can be prioritised and delivered alongside ongoing commitments. You will define and steward the architectural standards our products are built on, covering integration and interoperability, security and data handling, operability, and the non-functional characteristics that determine whether a system holds up in production. You will make those standards adoptable through reference implementations, templates, and working examples rather than written rules alone. This is deliberately a hands-on role: you will prototype to de-risk significant decisions, contribute production-quality code to shared foundations, and engage directly in the hardest technical problems, so your recommendations are grounded in what actually works. You will review solution designs and technical proposals early enough to change the outcome, establishing a repeatable assurance process across all delivery, and advise on technology selection and significant investment decisions with an honest assessment of long-term cost, flexibility, and constraints. You will lead architecture discussions with both technical and non-technical audiences explaining choices in terms of cost, risk, and delivery impact, and driving each to a clear, documented decision. Much of your impact will come through influence rather than authority. As a senior technical contributor, you will set engineering standards, coach engineers on architectural thinking, and grow this capability across the organisation.

Minimum Qualifications

• Extensive hands-on software engineering experience, with a demonstrable track record of designing and building applications end to end, including several years in a principal engineer, architect, or equivalent senior technical role
• Deep expertise in web application development, with genuine fluency in at least one of the programming languages - Python, or Java and the ability to reason about and review the others, and hands-on experience with modern web frameworks and libraries such as React, FastAPI, Flask, Django, SpringBoot, Hibernate
• Strong grounding in relational data modelling (Postgres or equivalent) and in the design of APIs, service integrations, and event-driven interfaces
• Practical experience with externally-facing systems, including authentication and authorisation, content delivery, rate limiting, auditability, and the associated security posture
• Track record of leading architecture conversations to a decision, including with stakeholders holding competing priorities and limited technical background

Preferred Qualifications

• Experience in advertising or marketing technology domains, including ad trafficking, campaign management, and creative asset management
• Experience introducing an architecture practice — ADRs, review forums, published standards — into an organisation, and driving genuine adoption rather than nominal compliance
• Experience with platform and developer experience work that measurably reduced time to first release for other teams