Senior .NET Performance Engineer

Servicepath

6d • Remote

About The Position

We are looking for a Senior .NET Performance Engineer to own the runtime health and throughput characteristics of our platform. This is a specialist contributor role — you won't be building feature logic, you'll be ensuring the systems that run it do so efficiently, reliably, and at scale. Our platform handles complex revenue lifecycle calculations across large contract datasets, with high-throughput data pipelines and long-running services that demand careful memory management and tuning. If your instinct when something feels slow is to open a profiler rather than add a cache, this role is for you. At servicePath™, we seek candidates who are eager to enhance performance by leveraging tools and technologies like AI. Our goal is to streamline tasks, increase efficiency, and maximize productivity, making work more manageable while driving organizational success.

Requirements

• 5+ years of .NET / C# development with a demonstrable specialism in performance engineering
• Deep, hands-on experience with .NET profiling tools — dotMemory, dotTrace, PerfView, Visual Studio Diagnostic Tools, or equivalent
• Strong understanding of .NET memory management internals — GC generations, LOH, pinned objects, finalisation, and how allocation patterns affect runtime behaviour
• Experience optimising high-throughput data processing pipelines — including async/await patterns, Channel<T>, pipelines, and avoiding synchronisation bottlenecks
• Proven ability to diagnose large dataset query performance issues across both relational (SQL) and document databases, including index analysis and query plan interpretation
• Familiarity with ETW, EventPipe, and diagnostics tooling (dotnet-trace, dotnet-counters, dotnet-dump)
• Strong benchmarking discipline — BenchmarkDotNet, reproducible test conditions, and regression tracking
• Ability to communicate findings clearly across engineering teams

Nice To Haves

• Experience with RavenDB or other document databases at scale — including index optimisation, bulk operations, and storage engine behaviour under load
• Familiarity with Span<T>, Memory<T>, ArrayPool, and other low-allocation patterns introduced in modern .NET
• Background in financial, billing, or revenue platform engineering where calculation correctness and throughput are both non-negotiable
• Experience with distributed systems performance — service mesh latency, serialisation overhead, connection pooling, and inter-service call optimisation

Responsibilities

• Profile, diagnose, and resolve performance bottlenecks across .NET services — from GC pressure and memory leaks to thread contention and I/O saturation
• Own memory management strategy across long-running services — heap allocation patterns, LOH fragmentation, finaliser queues, and GC tuning (gen0/1/2, server vs. workstation, DATAS)
• Investigate and optimise high-throughput data pipelines — batch processing, streaming patterns, buffer management, and backpressure handling
• Identify and resolve large dataset query performance issues — index utilisation, query plan analysis, pagination strategies, and aggregation efficiency across both relational and document databases
• Establish and maintain performance benchmarking infrastructure using BenchmarkDotNet and load testing tooling — define baselines, track regressions, and gate releases on performance criteria
• Conduct performance-focused code reviews — identify allocations, boxing, closure captures, LINQ misuse, and other common .NET performance anti-patterns
• Collaborate with product engineers to surface performance constraints early in design, without blocking feature delivery
• Produce clear diagnostics and findings documentation that non-specialists can act on

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level
• Education Level: No Education Listed
• Number of Employees: 11-50 employees