Principal Software Architect

Principal Software Architect Location: This is a 100% remote role open to those who reside in the United Kingdom, Poland, or Czech Republic

About the job

Testlio ’s fully managed crowdsourced testing platform, powered by our proprietary intelligence technology - LeoAI Engine™, integrates expert, on-demand testers directly into your release process. Ship faster and more confidently with global coverage across 600,000+ devices, 800+ payment methods, 150+ countries, and 100+ languages. To learn more, visit testlio.com .

We are hiring a Principal Architect to serve as a hands-on individual contributor who will shape our application and platform architecture, driving production-ready systems that directly enable our next generation of intelligent, distributed software testing solutions. Why will you love this job?

High Ownership and Autonomy: Be a foundational technical leader steering a profound platform transformation, making critical structural decisions that balance immediate system delivery with long-term enterprise scalability. Pragmatic AI & System Innovation: Step past the hype to integrate actionable AI capabilities directly into high-throughput surfaces, modernizing our core monolith into a robust distributed network alongside our product and executive leaders.

Why will you love being a part of Testlio? Great Culture: Testlio is a female-founded company, and half of our team identifies as women. We’re proud of our inclusive, purpose-driven culture where people genuinely enjoy collaborating. As part of our team (we call ourselves TestLions), you’ll help create exceptional digital experiences for our customers, while also contributing to our freelance network. Remote Work: Our culture is built around remote work.

We’ve created systems to allow us to successfully work together asynchronously as a fully remote and globally distributed team. Testlio provides the tools and guidance for everyone to succeed in their careers in a fully remote setting. Our working style encourages everyone to make decisions, communicate effectively, and work at a sustainable pace. Investment in You: Your growth and well-being matter to us.

You’ll have flexible paid time off—including national holidays, personal days, and sick days—plus stock options so you can grow with Testlio. We also provide a $300 annual learning stipend to support your personal and professional development. Winning Business: Testlio is growing, profitable, and cash-strong. We are leading our industry with exceptional clients who provide us with a high NPS score and a 4.7 rating on G2.

Our business model is global, enterprise, and subscription-based. Several of our largest clients have been with us for 7+ years, and many spend $500K+/year with Testlio. What would your day look like? Architect, develop, and deploy scalable, production-grade services directly across the core Testlio software platform. Author clear architectural standards and reference patterns that define domain boundaries, decoupling our current codebase into modular services.

Partner with the Director of Engineering to execute frontend framework consolidation, improving operational performance and observability. Safeguard system efficiency and regulatory posture by designing with security, cost-efficiency, and ISO 27001 expectations at the center. Integrate secure AI/LLM patterns into customer-facing surfaces, establishing strict operational guardrails and failure modes for our Quality API.

Advise executive, product, and engineering teams on major technical tradeoffs, translating business needs into clean technical strategies. What do you need to succeed? Technical Skills 15+ years of hands-on software development experience building cloud-native, business-critical platforms. Advanced mastery of distributed system patterns, data modeling, event-driven design, and database technologies (Relational and NoSQL).

Proven track record designing and migrating application infrastructures, specifically moving from monolithic architectures to modular services. Deep experience establishing enterprise-ready patterns in AWS, emphasizing high availability, cost optimization, and secure infrastructure. Strong familiarity with modern full-stack code environments, including front-end web frameworks, scripting languages, and CI/CD pipelines.

Practical, production-grade experience deploying AI/ML or LLM-based solutions with an emphasis on observable, safe automation patterns. Human Skills Fluency in English with exceptional written and verbal communication skills, especially when presenting advanced architecture concepts to business leaders. Ability to operate effectively as an individual contributor in fast-paced, ambiguous environments, showing proactive problem ownership.

Strong collaboration and alignment focus, capable of guiding distributed engineering teams and technical peers without direct authority. Outstanding analytical thinking, balancing a broad long-term technology vision with practical, short-te