.NET Performance Engineer

.NET Performance Engineer- Global tech. company - UK - remote

Excellent opportunity to join a new team, owning the runtime health and throughput characteristics of the platform. This is a specialist contributor role — you wont be building feature logic, you'll be ensuring the systems that run it do so efficiently, reliably, and at scale.

Skills/experience

.NET / C# development with a demonstrable specialism in performance engineeringDeep, hands-on experience with .NET profiling tools — dotMemory, dotTrace, PerfView, Visual Studio Diagnostic Tools, or equivalentStrong 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, 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)

AI development experience - usage of AI tools (Claude, CoPilot, ChatGPT) - desirable

Duties:

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 handlingIdentify 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

Excellent company, team and opportunities, apply now!!