Job Description:
Job Specification: Senior Software Architect / Principal Engineer
Legacy System Modernisation & AI-Enabled Engineering
Position Title
Senior Software Architect / Principal Software Engineer
Position Summary
We are seeking a highly experienced Senior Software Architect / Principal Engineer to lead the strategic rewrite and modernisation of a large-scale legacy software platform. The successful candidate will be responsible for architecture leadership, technical governance, delivery oversight, and hands-on engineering guidance throughout the transformation programme. This role requires deep experience in legacy system assessment, migration planning, fourth-generation language environments, modern software engineering practices, AI-assisted development tooling, and enterprise-scale platform modernisation.The candidate must be capable of operating at both strategic and technical levels, guiding architecture decisions while actively mentoring engineering teams and ensuring successful delivery of a modern, scalable, maintainable platform.
Key Responsibilities
Architecture & Modernisation Leadership
Lead the end-to-end rewrite and transformation of legacy enterprise systems into modern architectures.
Analyse existing applications, dependencies, business rules, integrations, and technical debt.
Define modern target-state architecture, migration strategy, and phased implementation roadmap.
Design scalable, resilient, secure, and cloud-ready enterprise solutions.
Establish software engineering standards, architecture governance, and development best practices.
Ensure business continuity during migration and coexistence between legacy and modern platforms. Provide strategic recommendations regarding refactoring, replatforming, rebuilding, or hybrid modernisation approaches.
Technical Leadership
Provide hands-on technical leadership to development teams.
Mentor senior developers, technical leads, and architects.
Conduct architecture reviews, code reviews, and engineering quality assessments.
Define CI/CD, DevOps, testing, observability, and deployment standards.
Oversee integration architecture and API enablement strategies.
Ensure scalability, performance, maintainability, and security requirements are met.
AI-Enabled Software Engineering
Drive adoption of AI-assisted software engineering tools and development environments.
Utilise AI agents and coding assistants to accelerate software development, testing, documentation, analysis, and migration activities.
Evaluate and implement AI engineering workflows, automation tools, and intelligent developer productivity solutions.
Guide teams in the practical and governed use of AI within the software development lifecycle.
Legacy System Expertise
Assess and modernise applications built on legacy or fourth-generation platforms.
Translate legacy business logic into modern architectures and programming languages.
Define strategies for data migration, integration abstraction, and incremental replacement.
Identify risks associated with legacy dependencies and propose mitigation strategies.
Stakeholder Engagement
Work closely with executive leadership, business stakeholders, product owners, and project managers. Translate business requirements into technical architecture and implementation strategies.
Present architecture decisions, technical risks, and delivery progress to senior stakeholders.
Collaborate with infrastructure, security, data, and operational teams.
Minimum Requirements
Experience
Minimum 15+ years of software engineering experience.
Minimum 8+ years in software architecture or principal engineering roles.
Proven experience leading enterprise-scale legacy system rewrite or modernisation initiatives.
Demonstrated experience managing complex software transformation programmes.
Strong background in enterprise integration and distributed systems.
Experience working in regulated or mission-critical enterprise environments advantageous.
Technical Skills
Legacy & Fourth Generational Language Technologies
Experience with one or more of:
Progress / OpenEdge
PowerBuilder
Informix Fourth Generational Language
Oracle Forms
COBOL integration environments
Delphi or similar legacy platformsModern Technologies
Strong experience with:
Python
Java
C#
JavaScript / TypeScript
Modern backend frameworks and API development
Microservices and service-oriented architecture
Cloud-native architecture
RESTful APIs and integration frameworks
SQL and modern database platforms
AI Development Tooling
Experience with:
AI-assisted development environments
AI coding assistants and autonomous agents
Intelligent code analysis and migration tooling
Prompt engineering for software engineering workflows
AI-enabled testing and documentation generation
Developer productivity platforms leveraging generative AI
DevOps & Delivery
CI/CD pipelines
Git-based workflows
Automated testing frameworks
Containerisation and orchestration technologies
Cloud platforms (AWS, Azure, or GCP)
Observability and monitoring toolsPreferred Qualifications
Bachelor's Degree in Computer Science, Information Systems, Engineering, or related field.
Postgraduate qualification advantageous.
TOGAF, cloud, or architecture certifications advantageous.
Experience with enterprise architecture frameworks.
Experience in financial services, ERP, telecommunications, or large enterprise platforms advantageous.
Key Competencies
Strategic thinking and architectural vision
Strong analytical and problem-solving capability
Excellent leadership and mentoring skills
Strong communication and stakeholder management
Ability to manage complexity and ambiguity
Strong governance and decision-making capability
Delivery-focused mindset
High attention to quality and maintainability
Personal Attributes
Highly professional and accountable
Technically authoritative
Pragmatic and solution-oriented
Adaptable and innovative
Collaborative leadership style
Continuous learning mindset, particularly in emerging AI technologies
Success Measures
Successful migration and modernisation of legacy systems
Reduced technical debt and operational risk
Improved scalability, maintainability, and performance
Increased engineering productivity through AI-enabled tooling
Successful delivery within agreed timelines and quality standards
Establishment of modern software engineering best practices
Employment Type
Full-time / Contract (depending on project requirements)
Seniority Level
Executive Technical Leadership / Principal Level
Reporting To
CEO