Performance Engineer Jobs

About The Position

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