Principal Software Engineer, Platform Optimization

The Principal Software Engineer for the Platform Optimization team drives the design and implementation of performance, scalability, and reliability improvements across isolved’s HCM platform, with a specific focus on enabling the product to serve large enterprise clients. This is a hands-on engineering role that sits within the Platform pod, working on the systemic challenges that emerge as client size, data volume, and transaction throughput increase. This is a senior development role that requires strong architecture thinking, but the day-to-day is hands-on coding, not high-level design from a distance. Our modernization strategy is built on hiring fewer, highly senior engineers who use AI-assisted development as a force multiplier, and we expect you to leverage agentic coding, spec-driven development, and AI-augmented code review as a core part of how you work, not as an experiment.

The successful candidate will help drive the technical direction for identifying and resolving platform bottlenecks that impact large-company deployments, and then do the work to fix them. This is a hands-on role. The expectation is that you are diagnosing performance issues, designing solutions, and coding the improvements yourself, from database query optimization and caching strategies to service architecture changes that support multi-tenant scale, not handing off specifications for others to implement. You will instrument, measure, and improve system performance, establishing patterns and guardrails that prevent regression as new features are built. This role requires the ability to think at a systems level about performance and distributed systems, while staying close to the codebase every day.

Core Job Duties

• Designing and implementing scalability and performance improvements that enable isolved to reliably serve large enterprise clients
• Identifying systemic platform bottlenecks through profiling, load testing, and production telemetry analysis, and developing strategies to resolve them
• Establishing performance budgets, benchmarks, and monitoring standards that prevent regression as the platform evolves
• Implementing patterns for multi-tenant scalability, data partitioning, and resource management, and sharing that knowledge with the broader team through code reviews and hands-on collaboration
• Performing code reviews with a focus on performance implications, query efficiency, and resource utilization
• Collaborating with product management and customer-facing teams to understand large-client pain points and translate them into technical improvement plans
• Driving adoption of caching, indexing, and query optimization strategies across the platform’s data tier
• Raising the bar on performance engineering practices, load testing methodologies, and production observability across the team through hands-on collaboration and code reviews
• Using AI-assisted development tools - including agentic coding, spec-driven development, and AI-augmented code review - as a core part of your daily workflow to maximize velocity and code quality, and helping establish AI-augmented development practices across the team

Job Complexity

As an expert in the field, uses professional concepts in developing resolution to critical issues and broad design matters. Anticipates broad changes pertaining to their area of expertise and ensures isolved is always ahead of the curve. Significant barriers to entry (e.g., top management review, approval) exist at this level.

Typically requires a minimum of 10 years of related experience with a Bachelor’s degree., * 10+ years developing web applications and services

• 3+ years developing cloud-native applications
• Demonstrated experience with performance engineering and optimization at scale
• Demonstrated use of AI-assisted development tools (GitHub Copilot, Claude Code, Cursor, or similar) as part of professional development workflows
• Ability to work independently to research and solve complex problems

Strong skills in:

• Azure (App Services, Functions, SQL, Redis, Application Insights)
• Microservice Architecture
• C#
• SQL Server performance tuning and query optimization
• Unit Testing
• .NET / ASP.NET Core WebAPI
• Load testing and performance profiling tools
• Experience with:
• Distributed caching strategies (Redis, Azure Cache)
• Database indexing, partitioning, and sharding patterns
• Application Performance Management (APM) tooling
• SOLID principles
• JavaScript
• Experience with the following a plus:
• Experience optimizing multi-tenant SaaS platforms
• Azure CosmosDB or other NoSQL databases
• Pub/Sub and asynchronous messaging
• Docker and container orchestration
• Experience with large (500+ table) system development
• Terraform or infrastructure-as-code

Physical Demands

Prolonged periods of sitting at a desk and working on a computer. Must be able to lift up to 15 pounds.

Travel Required

Yes, up to 10% domestic travel may be required.

Work Authorization

Employee must be legally authorized to work in the United States.

isolved is a leading provider of human capital management (HCM) solutions that combines modern technology with expert services and support. Purpose-built for People Heroes , isolved gives HR, payroll and benefits leaders the tools and insights to streamline operations and deliver employee experiences that matter. isolved People Cloud is a connected HCM platform with built-in artificial intelligence (AI) and analytics that brings together HR, payroll, benefits, workforce management and talent management in one experience. Built on a legacy of 40 years in the market, isolved is trusted by more than 200,000 employers and used by 9 million U.S. employees, representing about one in 20 American workers. Visit www.isolvedhcm.com.