QGIS is the swiss army knife of geospatial computing.
I use it daily, and frequently, for all sorts of work building a location API SaaS company. It's a sterling success of open source, on par with as impactful as Linux, for the geospatial world (IMO).
I tried to perform what I thought were basic tasks of drawing a few line segments and measuring geodesic distances between two points, but I needed a janky plugin for the former and never figured out how to do the latter.
I really do want to learn it however, since it's a lot easier sometimes to work interactively than doing everything in Python code, and I know QGIS is supposed to be a very powerful tool in general.
I learned QGIS arguably the hard way (creating a new non-Earth global basemap from scratch, with no prior GIS experience) but:
- The QGIS Training Manual is good. Not great; don't be afraid to go out of order after the first few modules to get to parts useful to you, because the module organization after "Creating Vector Data" stops being terribly linear. https://docs.qgis.org/3.22/en/docs/training_manual/index.htm...
- https://www.qgistutorials.com/en/ is more project- and task-oriented, and where I learned georeferencing and digitizing (drawing over raster maps)
You can measure distances natively in QGIS, the symbol looks like a ruler. Adding permanent points requires adding a layer, e.g. a shapefile of points.
That being said, as I've outlined in the article, I certainly haven't properly learned it...
But having dabbled in Python/Folium and the like (most recently did geo vis with Superset for another article), some of the datasets and functionalities were familiar (I also had to do point-in-polygon problems in Python, way back when, so maybe that mental scar helped :) ). I found random blog articles and stackexchange posts for specific questions I got stuck on the most helpful.
For instance, I have this link saved: https://gis.stackexchange.com/questions/421467/not-geotagged... , which got me down the rabbit hole of "Oh, you can make a style a function of other things? You can read EXIF? How neat!" (where I then found some other posts).
What I will say, almost everything online is out of date - the GUI changed frequently, plugins are now native functionalities etc. The HTML tooltip thing I did is also a modification of an older blog article (which I'm afraid I didn't save), whereas the contour line styling I took verbatim from the article I linked in that paragraph.
What search terms would one use for finding roles in companies like this, as an experienced dev with a strong background in GIS and open source tools? E.g. Postgis/Pydata/mapbox-gl et. al.
GIS is a huge space, and you could specialize in one niche for years or go more general, so it's really based on what you want to do.
I'd say there's three or four general areas: mapping & map data (mostly focused on visualization), geocoding & search (focused on helping people find things in natural language, think text -> coordinates, text -> point of interest -> coordinate), routing (focused on the mechanics of getting things from point a to point b efficiently), and finally a huge, diverse bucket of "other location APIs" (anything from geofencing to timezones to ETL specialization).
I'm happy to chat about this. We aren't hiring, but there are lots of companies that are.
I use it daily, and frequently, for all sorts of work building a location API SaaS company. It's a sterling success of open source, on par with as impactful as Linux, for the geospatial world (IMO).