Principal Engineer (Software Architecture and Modernization)

Location: Remote, Poland

Salary: PLN 460,000–470,000 annually, with potential additional bonuses, commissions, equity, or other incentives.

Company

hirify.global provides scalable, data-driven software solutions for fitness businesses, supporting clubs, coaches, members, and payment operations worldwide.

What you will do

• Lead the architecture and hands-on modernization of legacy, database-centric applications into domain-oriented software.
• Define architecture, module and service boundaries, migration paths, compatibility strategies, and incremental implementation plans.
• Contribute directly to backend code, prototypes, refactoring, code reviews, production fixes, and runtime improvements.
• Design domain models, APIs, persistence, transactions, caching, messaging, and event-consumer patterns.
• Improve correctness, performance, concurrency, reliability, testing, static analysis, dependency management, and production validation.
• Partner with engineering, product, security, and data teams to turn technical strategy into executable cross-team initiatives.

Requirements

• Substantial experience designing, building, operating, and evolving production backend systems, APIs, services, and distributed applications.
• Hands-on implementation experience with backend ecosystems such as Java/Spring Boot, Golang, Node, or TypeScript.
• Strong knowledge of domain modeling, service boundaries, migration strategies, modular design, refactoring, and architecture for complex existing systems.
• Experience with relational databases, SQL, messaging, event consumers, data movement, caching, and legacy data dependencies.
• Expertise in diagnosing and improving correctness, concurrency, performance, recovery behavior, and production reliability.
• Principal-level technical leadership, communication, testing discipline, code review, static analysis, dependency management, and secure coding practices.

Nice to have

• Experience modernizing large systems, upgrading frameworks and runtimes, decomposing monoliths, or extracting services.
• Experience with Oracle, Kafka, complex data migrations, reporting dependencies, profiling, instrumentation, concurrency analysis, or database-performance tuning.
• Experience applying AI coding agents to codebase analysis, implementation, testing, and modernization.

Culture & Benefits

• Values-focused culture built around Best Life, One Team, and Growth Mindset.
• Open paid time off and quarterly company-wide Days of Disconnect.
• Parental and pet-parent leave, fitness reimbursement, and partner discounts.
• Medical, dental, and vision coverage, employee assistance support, and Calm App access.
• Inclusive workplace focused on diversity, equity, belonging, and professional growth.