Head of Architecture | C# / .NET | Legacy Decomposition | Azure | Influence Without Authority

Head of Architecture | C# / .NET | Legacy Decomposition | Azure | Influence Without Authority | Fully Remote (UK)

Salary: Up to £100,000 + Benefits

Contract: Permanent

Start: ASAP | We can only consider applicants with 4 weeks notice of less for this one

Working model: Fully remote (UK-based applicants only) - London office available for anyone who wants it Eligibility: UK applicants only - no visa sponsorship

Required: Senior architecture leadership on a complex, live platform | Legacy decomposition | C#/.NET | Azure | Regulated environment | Influence without authority (Non-Negotiable)

This is the senior-most individual contributor seat in the engineering function - the person accountable for technical coherence across the entire platform. Not a people manager. Not a meetings-and-decks consultant. A builder.

🚨 Please only apply if you have ALL of the following 🚨

• Significant experience as a senior architect or principal engineer on a complex, multi-year platform - evolving a live system under delivery pressure, not greenfield
• Proven, hands-on legacy decomposition: strangler fig patterns, service boundary definition, data migration sequencing - you know why big-bang rewrites fail
• Deep fluency across C#, .NET (Framework + modern), SQL Server at scale, Azure, RabbitMQ, Redis, CI/CD - you don't need to ship production code daily, but you must read any part of the codebase and make real architectural calls
• Experience operating in a regulated environment (PCI DSS, ISO 27001, Cyber Essentials or equivalent) and how compliance shapes architecture
• A track record of influence without authority - you've driven standards adoption across teams that didn't report to you, via a forum / guild / chapter model, and can point to the outcomes
• Strong communication across registers - whiteboard with engineers one minute, plain-language summary for commercial stakeholders the next
• Experience mentoring and growing senior engineers - building their judgement, not dependency on you

The Company

An established, profitable UK technology business running a large-scale, business-critical platform in a regulated, mission-critical sector. Very high transaction volumes, a growing enterprise customer base, and a serious engineering bar. The team is mid-modernisation - consolidating delivery, evolving a mature C# platform, and standing up a proper architecture function. Strong senior practitioners already in place (Tech Leads, Staff Engineers, a Principal Security Engineer). This role channels that talent into one coherent direction.

Role Overview

A brand-new, high-impact role with executive backing and a clean canvas. You'll define and stand up the architecture function from the ground up - the target architecture, the ARB process, the Architecture Guild, and the engineering standards that shape how the whole platform gets built. You'll report to the Head of Engineering.

This is influence, not command. The standards land because they reflect what the best engineers already know to be right - shaped with the senior technical leadership, not handed down.

What You'll Own

• Target architecture - a living 12–24 month view of where the platform goes, what moves when, where the service boundaries sit
• ARB process - the template, cadence, and culture; a forum that produces decisions, not discussion
• Architecture Guild - you chair it; designated members from each team are how your work becomes real practice
• Decomposition sequencing - a principled backlog for moving on from the legacy monolith, aligned to delivery capacity and commercial priority
• Observability standard - driving the shift from infrastructure monitoring to outcome-based SLOs (latency, error rate, user impact)
• Engineering standards - coding standards, integration patterns, API contracts; developed in partnership, held authoritatively once agreed
• Security architecture partnership - joint ownership of technical security posture with the Principal Security Engineer
• Technical hiring - shaping the bar, contributing to calibration and interview panels

This role is NOT

• A line manager for delivery engineers
• A hands-on feature developer
• A gatekeeper who approves or blocks delivery - you enable it
• A "rewrite everything" mandate - change happens in sequence, on a live platform

Nice to Have

• Experience in regulated, high-volume transactional domains (payments, fintech, or similar)
• Familiarity with open-standard protocols for payments or secure transactions
• Defining and driving an SLO-based observability posture across multiple services
• Microservices / AKS / Kubernetes at production scale
• Architecture certification (TOGAF, Azure Solutions Architect, or equivalent) - useful context, never a substitute for delivered outcomes
• AppSec / secure design review background

If you've stood up an architecture function on a live, complex platform and you get standards adopted by being right - not by holding the org chart - get in touch for a fast response.