Which laptop to choose for school / university, and which to choose for a developement job?

Which laptop to choose depends on a number of factors, like your budget, open source ethics, choice of operating system and what kind of developement software you use. Altough these factors are important to consider, in general, most programming related activities, are low on resource intensivenes and would therefore not require great amounts of processing power. The exceptions to this rule would be using or creating cpu / gpu heavy software like games, 3D or managing wast amounts of data.

Choice of operating system

There are three main contenders when it comes to choosing an operating system: Windows, Mac OSX and Linux. The choice of operating system will depend on what type of laptop you buy. Altough it´s possible to run Mac OSX on a non Apple device, I would not recommend it based on lack of stability and support. The legality of it is also questionable.

Linux is a good choice for most software developement, unless you require proprietary software, in which case you are probably out of luck. It is therefore important to identify your use cases (choice of development software, etc ...) and the requirements from your school or place of work.

In my experience, many universities require you to run proprietary software on your computer - which locks down your system - when taking exams in order to prevent you from cheating. I had to learn this the hard way when I was running Arch Linux on my laptop hehe.

The Linux ecosystem is wast, and there are many different distributions or variations of Linux to choose from. I would personally recommend Ubuntu for the beginner, and Arch Linux for the more intermediate Linux user.

Lenovo Thinkpad

The Thinkpad line of laptops where originally developed by IBM before being bought by Lenovo. Lenovo has thus far been true to the laptops origins and still develop good quality Thinkpads fit for developement.

The Thinkpad is very conventient for developers as it´s known to be reliable. It has a true and time tested design, with an alright keyboard. The Lenovo line of computers run Windows by default, but Linux support is also great.

Thinkpads are also more affordable than the other contenders, offering latest models to as low as $800 dollars. Even the lower priced models have good specs. Altough, if you´re looking for an even greater deal, you can find previous models to half the price, or lower.

Macbook Pro / Air

I use a Macbook pro 14 inch for work, as its small form factor makes it convenient. It fits nicely in a small backpack which is something I value. The Macbook Pro also packs quite a lot of power, which is nice if the need for running more demanding software comes down the line. Mac OSX supports most of the same developement software that Windows and Linux does.

As Mac OSX is based on Unix, just like Linux is, it´s easy to transfer terminal based knowledge between the two systems.
Apple´s ecosystem makes it seamless to pair a mac with an iPhone, altough it might be a turnoff for some to have to buy into the Apple ecosystem.

System 76 and Purism

Both these vendors offer Linux based laptops in different performance brackets. System 76 offers laptops running either Pop!_OS or Ubuntu. They offer systems with great performance, altough the form factor and weight is bigger than that of a Macbook.

Purism, at the time of writing, offers the Librem 14 laptop, which they claim to be the first 14 inch laptop to protect your digital life. It is ultra portable, and designed from the ground up to be privacy, secure, and freedom respecting. Purism also offers the privacy respecting Librem 5 phone, with an alternative version being manufactured in the USA.