We sometimes are too negative and forget that many times there's also a bright side about most situations. For example, when we don't end nicely a work relationship, we tend to only remember what went wrong (if it did, that is). This post is a small recapitulation of good things I've learned on each and every past job, no matter if it was overall a good experience or not.
At my first job, Eidos (now Alhambra-Eidos, and NOT the videogame publisher) I had the luck of directly learning a good way to build software: 3-layer applications, separation of web templates and code, SQL Server stored procedures instead of SQL in strings, distributed components... They also hosted for free one of my defunct websites for many years.
At the second job, Surfernet, I did some of the coolest projects: A full MSN Messenger client from scratch (fully implemented the protocol), a Winamp-like MP3 player, and other nice applications with fancy graphics using Win32 API. It was physically exhausting (I worked from 8AM to 1PM, + going to university until 9PM) and schedule was always tight (usually projects took 1,2 months max.) but I learned a lot.
At the third job, I mostly developed the sense of teamwork. Development was a tiny fraction of the company and not well cared about, but the four of us took the daily job with tons of humor and smiles up to the day we left.
ilitia was the 4th job, and I lasted there for 4 years. On one side, it was a job where I matured a lot: Long times in a client, dozens of projects built in quite varied languages ranging ANSI C to advanced C# (.NET Remoting, threading in the pre-C# 2.0 era, ...), first time ever doing testing (even TDD!), setting up a .NET continuous integration server, my first usergroup and event talks (giving the first one in front of 200 geeks was really scary), even managing a small team of two people in my last months... On the other side, lots and lots of fond memories, parties, friends made (some of my best ones come from here).
Then came NAVTEQ, an important milestone because I got out of consulting. I learned to fight for what I think it is right, whenever it is the appropiate programming language (instead of a random management decision), pushing for rewriting components, or daring to peek into heavy algorithms-related code (I optimized an A* component). It was also the first time I had to talk in english at work but outside of events/talks.
Nokia shutdown NAVTEQ Madrid offices, and I ended up hired at Tuenti, another place where I've been almost 4 years. Here I got way out of my comfort zone, switching from a full .NET stack to a LAMP one (but hey, at least was object oriented PHP!). By far, Tuenti is the place where I've learned most and quickest, pacing being so fast that we joked about 6 months there being like 2 years at any other company. Lots of high scalability concepts, watching a website grow to millions of users and huge numbers of visits. It was a monolith but it worked nice and we were better than Facebook in Spain for quite some time. The "work hard, party hard" motto was 200% true, but I would repeat the experience without a doubt.
Minijuegos was the seventh job. Wanting to go back down to building big chunks of something from scratch (or almost) I joined. Between three people (CTO, a junior dev and me) we were able to fully build an online games portal, avatar generation system, CMS, APIs, payment gateways... I was able to put into practice theory learned in the past, work with asynchronous jobs... and work for once in something related with videogames! (my childhood dream). Things slowed down and tasks weren't so challenging but I did my "Mr. Wolf" role, got "version 1.0" done and made some good friends there too.
CartoDB (Vizzuality in 2014) was another radical shift, ditching my PHP and MySQL knowledge to start with Ruby (on and off Rails) and PostgreSQL, and this time moving to a full backend engineer role. There I learned a lot about databases, importing big amounts of data, manipulation and transformation of data, heavy DB-related operations, developing and maintaining APIs, and lots of interesting concepts of mapping and GIS (although I only grasped that world). I'm happy because I think I was able to hold up with a big part of the backend, alone for a while and then with some great colleages once we grew.
And now, The Motion marks the 9th job. I have lost sight of my comfort zone: now I'm working with Python, microservices, containers, AWS, managing a small team... And getting for once deep into devops tasks... We'll see how it goes ;)