We got 99 problems and a glitch is one






Devz Wit Attitudes

Our outsourced homie


X-Factor Effect™



Tracklist for today

  • Because I Got High (feat. Common Pitfalls)
  • Cache, Money, SEOs
  • Get Low (feat. Lil GC Pressure)
  • The Notorius C.P.U. (Spike's Tribute)
  • Big Poppa a.k.a. Size Matters (feat. BenchmarkDotNet)
  • When I'm Gone

Always measure.



There are only two hard things in Computer Science: cache invalidation and naming things. 

Phil Karlton

Umbraco performance gotchas

  • Examine Indexes
  • Media
  • Database hits
  • Singletons
  • Static Umbraco Context(s)
  • Events (lot of Events...)

Get Low!

Common performance drains

  • (The Notorious) C.P.U Spikes:
    • contentions (async calls!)
    • algorithms (e.g. hashing)
    • I/O
    • parsing (hi JSON!)
    • more...
  • GC / Memory Pressure
    • data structures
    • allocations
    • compiler gotchas


Class vs Struct

What is a Stack?
What is a Heap? 

Stack is a place in the memory where value types are stored.

Heap is a place in the memory where the reference types are stored.

Value Types

  • Int, Float, Short, Long...
  • Byte
  • Structs
  • Enums
  • Bool

Reference Types

  • Class
  • Interface
  • Array
  • String
  • Delegate
  • Tuple...

The great Eric Lippert once wrote 'The Stack Is An Implementation Detail' and basically that's not true anymore.

Jon Skeet

Think before the execution.

And after too

.ToString() or not .ToString(), that's the question...

JIT up, stand up!

a.k.a. compiler gotchas



ref & in

It's just the beginning...

Helpful tools & references

For the real hardcore playazz: WinDbg, SOS, PerfView and more!

Marcin Zajkowski & Callum Whyte

Senior Devs & Umbraco MVPs @ The Cogworks

#umbraCoffee Baristas @ YouTube (Friday's 12:30 on YT)







Thank you!

We got 99 problems and a glitch is one

By Marcin Zajkowski

We got 99 problems and a glitch is one

Is your website geared up to handle large amounts of unexpected traffic? Are you confident your site can "bear the load" without a hitch, allowing you to focus on more important things? What about doing all of this without an unlimited budget? Callum and Marcin's Umbraco site for their secret side project just went viral... But it keeps crashing which is ruining their street-cred! Sadly, the original developer left a few glitches behind and they need to be fixed pronto to avoid letting down their new-found fans... Using tools like remote debugging and performance profilers to fix "The Notorious C.P.U" spikes, they will work against the clock to resolve the glitches; featuring some common mistakes seen in Umbraco sites, and some more "Juicy" problems too... They'll share creative solutions to problems, such as scaling on a budget, and will benchmark all of their changes, with tools like BenchmarkDotNet, to prove their impact before pushing live.

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