Performance Engineer Sr

This is a developer-first role focused on improving system efficiency through code-level analysis, architectural insights, and data-driven optimization. You will work closely with engineering teams to identify performance bottlenecks, optimize execution paths, and ensure our platforms are highly scalable, reliable, and cost-efficient.

What you'll get to do

• Profile, analyze, and optimize application code to improve:

• Execution efficiency

• CPU, memory, and I/O utilization

• Latency and throughput

Conduct deep-dive investigations into performance issues using tools such as:

• SQL Profiler, dotTrace, DebugDiag, WinDbg, Fiddler, and observability platforms

Identify and resolve performance bottlenecks at the code, database, and system level, leveraging profiling data, logs, and telemetry

Analyze and optimize:

• C# / ASP.NET application performance (threading, async patterns, memory usage, behavior)
• Database queries and execution plans (MS SQL, MongoDB)
• Network calls and API behavior

Collaborate with developers and architects to:

• Embed performance considerations into system design
• Influence architectural decisions for scalability and efficiency
• Drive performance-focused code reviews

Optimize enterprise SaaS applications across:

• Multi-tier web architectures
• Microservices-based distributed systems

Design and execute capacity and scalability experiments to guide system sizing and cost optimization

Build and enhance tools to monitor, analyze, and visualize performance metrics in cloud environments

Analyze performance data and provide clear, actionable recommendations to engineering and product stakeholders

Leverage AI tools to automate analysis, optimize workflows, and improve engineering productivity

Contribute to and lead performance engineering best practices across teams

We are seeking a Senior Performance Engineer with a strong software engineering background and deep expertise in profiling, debugging, and optimizing application performance at scale., * Strong background in software development with a focus on performance optimization

• Proficiency in one or more programming languages:

• C# and Python

Strong experience with:

• ASP.NET / .NET application performance tuning and diagnostics

Experience with scripting and automation:

• Python, JavaScript

Deep hands-on experience with profiling and debugging tools, such as:

• SQL Profiler, dotTrace, DebugDiag, WinDbg, Fiddler

Strong experience with code-level profiling and optimization techniques

Hands-on experience with database performance tuning:

• MS SQL, MongoDB (query optimization, indexing, execution plans)

Proven ability to:

• Analyze and optimize code for quality, efficiency, and performance
• Diagnose complex performance issues in distributed systems

Solid understanding of:

• Microservices and distributed system design
• API performance and service interactions

Experience with observability and performance monitoring tools, such as:

• AppDynamics, OpenTelemetry, DBA Dash, Datadog, Prometheus, Grafana

Experience working with engineering workflows and tracking systems such as Jira

Demonstrated ability to integrate AI tools to optimize/redesign workflows and drive measurable impact

Strong collaboration and communication skills, with the ability to influence technical decisions What would make you really stand out

• Experience with performance testing tools (e.g., JMeter, Gatling, k6, LoadRunner)
• Familiarity with CI/CD pipelines and integrating performance validation into workflows
• Experience with containerization and orchestration (Docker, Kubernetes)
• Experience with advanced profiling techniques (e.g., flame graphs, heap analysis, thread dumps)
• Background in cloud cost optimization and efficiency engineering
• Experience with non-functional requirement (NFR) gathering and performance test planning

Dayforce is a global human capital management (HCM) company headquartered in Toronto, Ontario, and Minneapolis, Minnesota, with operations across North America, Europe, Middle East, Africa (EMEA), and the Asia Pacific Japan (APJ) region. Our award-winning Cloud HCM platform offers a unified solution database and continuous calculation engine, driving efficiency, productivity and compliance for the global workforce. Our brand promise - Makes Work Life Better - Reflects our commitment to employees, customers, partners and communities globally., Dayforce is fueled by the diversity of our talented employees. We are an equal opportunity employer and consider and embrace ALL individuals and what makes them unique. We believe our employees should be happy and healthy, with peace of mind and a sense of fulfillment. We encourage individuals to apply based on their passions. Dayforce encourages personal and professional growth. We offer excellent time away from work programs, comprehensive wellness initiatives and recognition through competitive pay and benefits. With a commitment to community impact, including volunteer days and our charity, Dayforce Cares we provide opportunities for you to thrive both in your career and personal life. Our focus is not just on your job but on supporting you to be the best version of yourself.