Principal Software Architect

Job Title: Principal Software Architect.

Role Purpose:

The Principal Software Architect is the senior technical authority for application and software architecture across Vistra's global technology estate.

This role defines the architectural vision, design standards, and engineering patterns that underpin Vistra's enterprise platforms, digital products, and client-facing services ensuring they are scalable, resilient, secure, and aligned to Vistra's platform-led, AI-enabled operating model.

Reporting to the EVP, IT Architecture & Engineering, this role bridges strategy and execution: translating enterprise architecture direction into actionable software design decisions, reference architectures, and engineering guardrails that accelerate delivery teams while maintaining architectural integrity.

The Principal Software Architect is expected to be hands-on leading by example through design authority, code-level credibility, and deep technical engagement with engineering teams across regions.

This is not a people-management role by default; it is a principal-level individual contributor with significant influence over technical direction, engineering culture, and platform outcomes across the enterprise.

Key Accountabilities:

Software Architecture & Design Leadership:

- Define and own Vistra's global software architecture strategy, standards, and design principles across enterprise platforms, digital products, and integration layers.

- Develop and maintain reference architectures, design patterns, and architectural blueprints for core domains including entity management, fund administration, financial accounting, and client portals.

- Lead architectural decision-making for major programmes and platform investments, producing high-quality High-Level Designs (HLDs) and Solution Architecture Documents (SADs).

- Establish and govern architecture decision records (ADRs), ensuring traceability and consistency of technical decisions across teams and regions.

- Drive adoption of domain-driven design (DDD), event-driven architecture, and microservices patterns where appropriate, while pragmatically managing legacy modernisation.

- Evaluate and recommend technology choices (languages, frameworks, platforms) based on fitness for purpose, total cost of ownership, and long-term maintainability.

- Act as the final technical escalation point for complex design challenges, trade-offs, and architectural disputes.

Cloud-Native & Platform Architecture:

- Define cloud-native application architecture standards across AWS, Azure, or GCP including compute, serverless, containerisation (Kubernetes/ECS), and managed services.

- Design platform-centric architectures that enable multi-tenancy, configurability, and service reuse across Vistra's business lines (VFS and VGS).

- Establish patterns for resilience, observability, and fault tolerance including circuit breakers, retry policies, health checks, and distributed tracing.

- Drive infrastructure-as-code (IaC) standards and ensure application architectures are deployment-pipeline friendly (CI/CD native).

API Strategy & Integration Architecture:

- Own and evolve Vistra's enterprise API strategy defining standards for API design, versioning, governance, security, and lifecycle management.

- Design integration architectures spanning synchronous (REST/GraphQL), asynchronous (event-driven, message queues), and batch processing patterns.

- Establish API gateway patterns, rate limiting, throttling, and consumer management standards.

- Drive the decomposition of monolithic systems into well-bounded services with clear contracts and minimal coupling.

Engineering Excellence & Technical Debt Reduction:

- Define and champion software engineering standards including code quality, testing strategies (unit, integration, contract, performance), and peer review practices.

- Lead technical debt identification, quantification, and structured remediation planning making debt visible and actionable for leadership.

- Drive modernisation of legacy systems through strangler-fig patterns, progressive decomposition, and pragmatic re-platforming approaches.

- Establish non-functional requirements (NFR) frameworks covering performance, scalability, security, accessibility, and maintainability.

AI & Automation Readiness:

- Ensure application architectures are AI-ready: API-first, data-rich, event-driven, and observable enabling intelligent automation and ML integration.

- Define architectural patterns for AI/ML model serving, feature stores, prompt management, and AI agent integration within business applications.

- Partner with Data & AI leadership to ensure platforms can consume and operationalise AI capabilities without architectural rework.

- Establish guardrails and patterns for responsible AI integration including data isolation, auditability, and human-in-the-loop design.

- Drive automation of repetitive engineering tasks through tooling, templates, and platform engineering approaches.

Governance, Assurance & Stakeholder Engagement:

- Participate in and contribute to enterprise architecture governance including design reviews, architecture boards, and investment assurance processes.

- Provide architectural assurance for major delivery programmes, ensuring solutions align with enterprise standards and long-term direction.

- Translate complex technical concepts into clear, business-relevant narratives for senior leadership and non-technical stakeholders.

Jobs To Be Done (JTBD):

The Principal Software Architect is accountable for delivering the following critical outcomes on behalf of Vistra:

1. Make Vistra's Platforms Scalable, Modular & Future-Ready:

- Ensure Vistra's core platforms can scale across regions and service lines without linear growth in complexity or cost.

- Deliver architectures that are modular enough to adapt to new business models, acquisitions, and regulatory requirements without wholesale rebuilds.

2. Accelerate Delivery Through Architectural Clarity:

- Provide engineering teams with clear reference architectures, design patterns, and decision frameworks that reduce ambiguity and speed up delivery.

- Shift architecture from a bottleneck to an accelerator enabling teams to move fast within well-defined guardrails.

3. Reduce Technical Debt and Eliminate Fragmentation:

- Make technical debt visible, quantified, and systematically addressed preventing it from silently eroding velocity and increasing risk.

- Drive convergence from fragmented, region-specific solutions toward standardised, enterprise-grade platforms.

4. Enable AI and Automation at the Application Layer:

- Ensure Vistra's application estate is architecturally ready to embed AI, automation, and intelligent workflows without requiring foundational rework.

- Create the conditions for non-linear productivity gains through platform-level intelligence.

5. Ensure Resilience, Security & Compliance by Design:

- Ensure application architectures meet Vistra's resilience, security, and regulatory requirements across all jurisdictions from inception not as retrofit.

- Partner with Security Architecture to embed zero-trust, data protection, and compliance controls into application design patterns.

6. Elevate Engineering Culture and Technical Maturity:

- Raise the bar on engineering practices, design rigour, and architectural thinking across Vistra's global development teams.

- Build a culture where good architecture is everyone's responsibility not a centralised function's gatekeeping activity.

Skills, Experience & Qualifications:

Required:

- Bachelor's degree in Computer Science, Software Engineering, Information Systems, or related discipline.

- 12+ years of experience in software engineering, with progressive movement into architecture roles.

- 5+ years in principal, staff, or senior architect roles with enterprise-wide scope and multi-region influence.

- Proven experience designing and delivering large-scale, distributed systems in cloud environments (AWS, Azure, or GCP) with the ability to create both high level and low level technology blueprint designs.

- Deep expertise in modern software architecture patterns: microservices, event-driven architecture, domain-driven design, CQRS, and API-first design.

- Strong hands-on proficiency in at least two of: Java/Kotlin, C#/.NET, Python, TypeScript/Node.js with breadth across the stack.

- Demonstrated experience with containerisation (Docker, Kubernetes), serverless architectures, and CI/CD pipeline design.

- Experience with enterprise integration patterns, API management platforms, and middleware technologies.

- Strong understanding of data architecture principles, including event sourcing, data mesh concepts, and analytics enablement.

Preferred:

- Master's degree in Computer Science, Software Engineering, or related discipline.

- Professional certifications such as AWS Solutions Architect Professional, Azure Solutions Architect Expert, TOGAF, or equivalent.

- Experience in regulated industries (financial services, professional services, fund administration, or corporate services).

- Experience architecting multi-tenant SaaS platforms or platform-as-a-product models.

- Familiarity with AI/ML integration patterns, LLM orchestration, and intelligent automation architectures.

- Experience leading architecture in organisations undergoing large-scale ERP or platform transformation programmes.

- Experience with Big Data solutions such as Databricks, Snowflake, Google Big Query an advantage.

- Experience in visualisation tools an advantage.

- Contributions to open-source projects, technical publications, or architecture community leadership.

Skills

Distributed Systems, System Design, System Architecture, Cloud, AI Integration, Microservices Architecture, Java, C#, Python, Node.js