Principal Software Architect

Remote from: EMEA
Salary, yearly, USD: 500,000
Department: Software Engineering
Employment type: Full Time,
Job posted: 25 Jun 2026
Apply before: 25 Jul 2026
Experience level: Senior
Views / Applies: 138 / 8

About company

About Testlio

We empower engineering leaders to deliver great global software.

Computer Software
2012

Actively Hiring

AI Summary

Testlio is hiring a Principal Software Architect for a fully remote role based in the UK, Poland, or Czech Republic. This hands-on individual contributor will shape application and platform architecture, driving production-ready systems for intelligent distributed testing solutions. The role involves high ownership, pragmatic AI integration, and modernizing a monolith into a distributed network. Testlio offers a great remote culture, growth investment, and a winning business. Ideal candidates have 15+ years of experience and advanced mastery of distributed systems and cloud-native platforms.

Role DNA

Job Complexity

Easy Hard

Pace & Pressure

Relaxed Fast-paced

Autonomy Level

Guided Full Ownership

Communication Load

Independent Highly Collaborative

AI Insight This role requires solving complex distributed system challenges, leading platform transformation, and integrating AI, which demands deep expertise and strategic thinking, making it the most difficult level.

Salary Analysis

AI Insight The offered salary of $500,000 is significantly above the typical US market range for a Principal Software Architect ($180k-$300k), possibly reflecting total compensation including stock options or a premium for specialized skills.

Key Skills

Software Architecture Distributed Systems Cloud-Native Event-Driven Design AI/ML Integration System Design Leadership Microservices Database Technologies ISO 27001

Cover Letter Sample

Dear Hiring Manager,

I am writing to express my strong interest in the Principal Software Architect position at Testlio. With over 15 years of experience building cloud-native, business-critical platforms, I have deep expertise in distributed systems, event-driven design, and modernizing monolithic architectures. I am drawn to Testlio's focus on pragmatic AI integration and high ownership, as I thrive in roles where I can drive strategic technical decisions while delivering production-grade solutions.

In my previous role, I led a major platform transformation, decoupling a monolith into microservices and establishing architectural standards that improved scalability and observability. I have also successfully integrated AI/ML patterns into customer-facing systems with strict guardrails. I am excited about the opportunity to advise executive teams and shape the next generation of intelligent testing solutions at Testlio.

I am particularly aligned with Testlio's inclusive culture and remote-first approach. My experience working across distributed teams has honed my ability to collaborate asynchronously while maintaining clear communication. I look forward to contributing to Testlio's continued growth and innovation.

Sincerely,
[Your Name]

Possible Interview Questions

Describe a time you led a major architectural transformation from a monolith to microservices. What were the key challenges and how did you address them?

In my previous role, I led the migration of a monolithic e-commerce platform to microservices. Key challenges included defining clear domain boundaries, managing data consistency, and ensuring zero downtime. I addressed these by using Domain-Driven Design to identify bounded contexts, implementing event-driven communication with an event bus for eventual consistency, and using a strangler fig pattern to incrementally replace functionality. The result was a modular system that improved scalability and reduced deployment time by 60%.

How do you integrate AI/LLM capabilities into production systems while ensuring security and reliability?

I follow a pattern of integrating AI via a dedicated service with strict operational guardrails. This includes implementing failover mechanisms, rate limiting, and input validation to prevent injection attacks. I also use an API gateway to log and monitor AI requests, and I design for graceful degradation—if the AI service fails, the system falls back to a deterministic response. Additionally, I ensure compliance with ISO 27001 by encrypting data in transit and at rest, and by conducting regular security audits of the AI pipeline.

How do you balance long-term architectural goals with the need to deliver features quickly?

I use the concept of 'architectural runway'—investing in foundational work that enables faster delivery later. I work with product managers to identify which features require new architectural changes and which can be built on existing patterns. I advocate for incremental improvements, like refactoring high-priority areas first while deferring less critical changes. Clear documentation and architectural standards also help teams make faster decisions without sacrificing quality.

Explain your experience with event-driven design and how you would apply it to a distributed testing platform.

Event-driven design is well-suited for distributed systems because it decouples services and improves scalability. In a testing platform, events like 'test started', 'bug found', or 'test completed' can be produced by testing agents and consumed by other services for real-time analytics, reporting, and alerting. I would use an event store for persistence and ensure idempotency in consumers to handle duplicates. This approach also enables asynchronous processing, which is critical for high-throughput environments.

How do you stay current with emerging technologies and ensure your architectural choices remain relevant?

I dedicate time each week to reading research papers, following industry leaders on platforms like InfoQ and ACM, and experimenting with new technologies in side projects. I also participate in architecture review boards and attend conferences to learn from peers. When making technology choices, I prioritize proven patterns and evaluate new tools through proof-of-concepts, considering factors like community support, scalability, and integration ease. I believe in pragmatic adoption—using the right tool for the job, not the trendiest one.

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-term implementation constraints.
Natural inclination for remote-first work, successfully communicating and documenting technical decisions asynchronously across global time zones.

What is the application process?

At Testlio, we aim to hire individuals who are excited about their role, thrive in a fully remote environment, and have strong long-term potential with our team. Because we are a fully distributed company, our interview process includes conversations with several team members so you can get a well-rounded understanding of the role, the people you’ll work with, and how we collaborate. As a result, our interview process typically takes 3–4 weeks to complete.

Interview Process:

Application
Recruiter interview
TestGorilla assessment
~ # Team and Stakeholder interviews
Reference checks
Offer & background check
Diversity and Inclusion

Testlio is an equal-opportunity employer deeply committed to creating an inclusive environment for people of all backgrounds and identities. We are female-founded, and 46% of our team members identify as women. For more information, see the DEI section of our website.

Apply now >