Performance Engineer Sr

Dayforce

4d•Remote

About The Position

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. 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.

Requirements

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.
Proven ability to diagnose complex performance issues in distributed systems.
Solid understanding of microservices and distributed system design.
Solid understanding of 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.

Nice To Haves

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.

Responsibilities

Profile, analyze, and optimize application code to improve execution efficiency, CPU, memory, and I/O utilization, and 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, GC behavior), database queries and execution plans (MS SQL, MongoDB), and network calls and API behavior.
Collaborate with developers and architects to embed performance considerations into system design, influence architectural decisions for scalability and efficiency, and drive performance-focused code reviews.
Optimize enterprise SaaS applications across multi-tier web architectures and 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.