Ciro Santilli's software engineering wisdom

Of course, "Ciro Santilli" with quotes, since all of those are either taken directly from others, or had been previously formulated by others.

Some anecdotes.

Ciro Santilli never splits up functions unless there is more than one calling point. If you split early, the chances that the interface will be wrong are huge, and a much larger refactoring follows.

If you just want to separate variables, just use a scope e.g.:

int cross_block_var;

// First step.
{
    int myvar;
}

// Second step.
{
    int myvar;
}

Ciro has seen and had to deal with in his lifetime with two projects that had like 3 to 10 git separate Git repositories, all created and maintained by the same small group of developers of the same organization, even though one could not build without the other. Keeping everything in sync was Hell! Why not just have three directories inside a single repository with a single source of truth?

Another important case: Linux should have at least a C standard library, init system, and shell in-tree, like BSD Operating Systems, as mentioned at: Section "Linux".

A slow development test cycle will kill your software.

New developers won't want to learn your project, because they would rather shoot themselves.

This means that build time, and the time to run tests, must be short.

5 seconds to rebuild is the maximum upper limit.

Of course, at some point software gets large enough that things won't fit anymore in 5 seconds. But then you must have either some kind of build caching, or options to do partial builds/tests that will bring things down to that 5 second mark.

You also have to spend some time profiling execution and build from scratch times.

A slow build from scratch will mean that your continuous integration costs a lot, money that could be invested in a new developer!

It also means that people won't bother to reproduce bugs on given commits, or bisect stuff.

One anecdote comes to mind. Ciro Santilli was trying to debug something, and more experience colleague came over.

To reproduce a problem, ciro was running one command, wait 5 seconds, run a second command, wait 5 seconds, run a third command:

The first thing the colleague said: join those three commands into one: And so, Ciro was enlightened.

Whenever someone asks:

I can only see this one thing different our setups, do you think it could be the cause of our different behaviour?

you don't need to read anymore, just point them to this page immediately. Virtualization for the win.

Sometimes you are really certain that something is a required substep for another thing that is coming right afterwards.

When things are this concrete, fine, just do the substep.

But you have to always beware of cases where "I'm sure this will be needed at some unspecified point in the future", because such points tends to never happen.

YAGNI is so fundamental, there are several closely related concepts to it:

The software engineer phrasing of simplicity is the ultimate sophistication.

Like all other principles, it is not absolute.

But it is something that you should always have on the back of your mind.

You aren't gonna need it is closely related, as generally the extra unnecessary complications are set in place to accommodate useless features that will never be needed.

The trivial takes a few hours.

The easy takes a week.

And what seemed hard takes a few hours.

As "deadlines" approach, feature sets get cut down, then there are delays, and finally a feasible feature set is delivered some time after the deadline.

The only deadlines that can be met are those of tasks which have already been done but not announced.

This is of course Hofstadter's law.

On the other hand, as a colleague of Ciro once mentioned, it is also known that the time it takes for a task to be done expands without limits to match the deadline. And therefore, without deadlines, tasks will take forever and never get done.

And so, in a moment, perceiving this paradox, Ciro was enlightened.

Once upon a time, when Ciro Santilli had a job, he had a programming problem.

A senior developer came over, and rather than trying to run and modify the code like an idiot, which is what Ciro Santilli usually does (see also experimentalism remarks at Section "Ciro Santilli's bad old event memory"), he just stared at the code for about 10 minutes.

We knew that the problem was likely in a particular function, but it was really hard to see why things were going wrong.

After the 10 minutes of examining every line in minute detail, he said:

I think this function call has such or such weird edge case

and truly, that was the cause.

And so, Ciro was enlightened.

Working remotely is hard if you don't already highly master the software and enterprise systems used.

Also you don't feel people's love as strongly, and usefulness is built on love, see also Steve Jobs's Pixar office space design philosophy.

But please, give workers a small silent office so that we can concentrate instead of a silly open space, and create an internal social network so people can see what others are doing.

Remote working is much better if the majority of the team also does it, otherwise you will get excluded. Maybe after VR...

When debugging complex software, make sure to keep notes of every interesting find you make in a note file, as you extract it from the integrated development environment or debugger.

Especially if your memory sucks like Ciro's.

This is incredibly helpful in fully understanding and then solving complex bugs.