Query Flex Engine process time with RegEx

# read flex engine log time
$contents = gc C:\Users\erik\Downloads\FlexEngine.log
[array]::Reverse($contents)

#$contents | where { $_ -ilike "*Starting Flex Engine*" } | select -First 1
$null = ($contents | where { $_ -ilike "*done*" } | select -First 1) -match "\((.*?)\)"

#$line
$Matches[1]