\begin{itemizep}
\item some problems that are trivial in imperative languages, can be very difficult to solve in idiomatic haskell and vice versa
\item practical cryptography is possible, but a difficult topic in haskell, see \url{https://mail.haskell.org/pipermail/haskell-cafe/2015-February/118059.html}
\item although haskell is \emph{lazy}, there are a few things that can break laziness, see \url{https://wiki.haskell.org/Maintaining_laziness}
\end{itemizep}