Lead Solutions Architect (Legacy to Cloud) in London

Solutions Architect - Legacy-to-Cloud Migration

Inside IR35, £500 - £800 P/D

6 months with scope to extend

Predominately remote with occasional travel

Active SC would be required

We are seeking experienced Solution Architects to provide end-to-end technical leadership across defined migration workstreams within a major large-scale legacy-to-cloud migration programme for a large, complex organisation.

A migration workstream is a logical grouping of applications or services with interconnected dependencies that must be discovered, designed, migrated, and cut over in a coordinated manner. The Solution Architect owns the technical direction, designs, dependencies, and readiness for all services within the assigned workstream.

This programme is responsible for safely and predictably migrating a large and diverse estate from legacy data centres into Cloud and other target hosting environments. The Solution Architect will ensure that all applications within the workstream follow a coherent migration approach aligned with the programme architectural principles, governance, and hosting constraints.

The Role

As a Solutions Architect, you will provide architectural leadership across all services within your workstream. You will own the technical understanding of the current landscape, define and communicate the migration direction, and coordinate the various technical teams delivering discovery, migration design, engineering uplift, and execution.

You will work closely with other Lead Architects, Engineers, Migration SMEs, cloud platform teams, target hosting SMEs, and client stakeholders to ensure the migration of your workstream is delivered safely, consistently, and in accordance with programme governance and security requirements.

This role requires strong architectural breadth, clear communication, technical authority, and the ability to drive alignment across multiple delivery squads.

Key Responsibilities

• Own the architectural direction for all applications and components within the workstream, ensuring alignment to programme standards and target platform patterns.

• Act as the single point of technical decision-making and design governance across the workstream.

• Provide leadership to Architects, ensuring technical clarity and consistency across teams.

• Ensure full and accurate discovery is completed for all services within the workstream.

• Consolidate discovery outputs into a coherent workstream-wide view of architecture, dependencies, integrations, and constraints.

• Validate assumptions, identify gaps, and ensure that discovery findings feed directly into migration design.

• Work with the Lead Platform Architect to define the migration approach for each service in the workstream (re-host, re-platform, relocate, uplift).

• Ensure migration designs reflect security requirements, target platform constraints, network patterns, IAM, storage, monitoring, and operational readiness.

• Oversee the creation and quality assurance of migration design documentation for each application.

• Identify, document, and manage cross-application dependencies within and across workstreams.

• Work with delivery management to define sequencing, align migration windows, and ensure readiness across all components.

• Coordinate with Cloud engineers, target hosting SMEs, security teams, network teams, and platform engineering groups to ensure migration readiness.

• Engage with legacy SMEs (e.g., Oracle, WebLogic, IIS, AIX, Solaris, COBOL, GEN) to understand constraints and required technical remediation.

• Provide technical oversight during migration execution and cutover events.

• Support troubleshooting and issue resolution across the workstream during execution.

• Ensure all services meet cutover readiness, rollback planning, and operational acceptance criteria.

• Represent the workstream in architectural and technical governance forums.

• Manage workstream-level technical risks, issues, decisions, and assumptions.

• Provide clear, concise technical updates to programme leadership.

Skills required

• Proven experience as an architect on large-scale legacy data centre exit, application migration or cloud transition programmes, with direct experience defining migration mechanisms, patterns, sequencing and cutover approaches.

• Strong architectural knowledge of legacy on-premise hosting and migration into Cloud and/or other target hosting environments. This is a migration architecture role rather than a greenfield cloud service design role.

• Experience across the following legacy technologies: Java, Oracle, WebLogic, IIS, Windows/Linux, AIX, Solaris, COBOL and GEN. Candidates are not expected to have deep expertise across every technology listed.

• Experience defining migration approaches and leading technical teams through discovery, design, and cutover.

• Strong understanding of platform level requirements: networking, IAM/security, access patterns, storage, resilience, monitoring.

• Ability to manage complex technical dependencies and coordinate multiple engineering teams.

• Excellent communication and stakeholder engagement skills, including working with senior client SMEs and multi supplier delivery teams.

• Experience operating within architectural governance and programme level technical controls.

Occasional weekend working may be required for planned deployment and cutover activity.