I transitioned into a backend engineering role 1 year ago after working as a data analyst for 3 years. The jump was definitely big to me, as I had to learn a lot of new concepts (OOP, clean code, architecture, devops etc). The transition was done through internal hiring where they did a live coding interview (2 easy leetcodes), a live system design interview, and motivational interview. I passed all of those and ended up in a high-paced team.
The team was severely understaffed. The manager was managing 3 teams that decreased from 20+ people to <10 people and there was hiring freeze. There was no proper onboarding and all the seniors were too busy with tasks to help me properly. I did my best to read the documentations and set up 1-1s with more senior engineers from other teams that could help me. I finished several projects although carried over some to the next half.
My 1st performance review was "meet expectations". However, before my 2nd performance review, there was a manager change and this manager gave me "partially meet expectations" and then said that I would be put on PIP program. When I asked the manager what the program would be like and how many people completed this successfully, he/she couldn't give a definitive answer and said that HR would be in touch me.
I decided to quit and spend time to learn more fundamental concepts and take up a freelance project. It's been 2 months since then. Right now I feel like I'm learning a lot in these 2 months compared to my 1 year in that company, but I can't help but feeling very anxious with all these layoffs and the incoming tech winter. I don't have any self-confidence within myself that I would get any decent job, especially after getting an incoming a PIP, I'm just worried that when I'm interviewing at my next job, the career gap in my resume and the past potential PIP would deter me from getting any jobs. I'm also at loss on how to avoid potential PIPs in the future. Any advice to help me? Thank you very much.
Edit: For more context, I didn't come from a CS background (I studied Mathematics). My team was not a revenue generator. The company was especially hit really hard during covid and had 2 big layoffs. When I left, there are many products that are being shut down and a couple of senior-level product managers left as well without being replaced due to hiring freeze. During the talk of my PIP, the manager brought up his/her expectations on me that was 1 level (mid-level) above my current level (junior-level).