Securing a job reference when about to be fired through a Performance Improvement Plan

Get the reference and move along. They are telling you that there is no future at this company.

It is very unlikely that they would be anything negative in a reference. We (random internet people) can't know what the motivation of you manager is. But you seem to imply that they are being truthful and somewhat on your side. If that is accurate, get them to give you a reference letter. If you can remind them of the successes without being heavy-handed, that would be helpful.

Working harder or better will not do anything.

No matter how hard you try, at the very best you may delay the termination. They have made up their mind, the PIP is just a means of legally saving them money.

And you are gleefully playing along. Never sign anything that is to your disadvantage. You are told you're doing a good job? Why would you sign a paper that states you're just doing ok? If your job has a union, join ASAP (and for your next job join immediately or stay in). You may even want to consult a lawyer.

However it is critical that you get a reference from your current manager asap (or at lease before the union/lawyer route gets known and/or your current manager leaves). Your new manager will not give you a good recommendation because that may be usable for constructive dismissal lawsuits, so as soon as your current (nice) manager is gone, your reference is too.

That being said, maybe be proactive about severance. They clearly want you gone and while PIPs are more or less safe from a companys point of view, they're already bending the truth to the point of you noticing so they may take the easy and safe route. This means that it may be advantageous for you to state your readiness to take it. Do this after consulting with a lawyer though because severance obviously excludes a settlement (or makes it far harder). This consultation may also give you a better perspective what amount of severance is realistic.

That all being said: start updating you resume, LinkedIn and so on.

I've been in this situation, in Canada.

Negotiate.

Your company wants you gone. It makes complete sense to negotiate a good severance package, and that's probably what you should do.

That said you first step should definitely be have a discussion with an employment lawyer. You need them to tell you what your rights are, and what your company could expect to pay if they try to lay you off without cause. That gives you a starting point for your negotiations. Definitely get in touch with other people in the same situation and consult a lawyer together. Splitting the cost of a lawyer two, four or six ways makes it very affordable, and the consultation will virtually certainly pay for itself.

Regarding your PIP; your lawyer will probably give you some hints, but make sure everything in the PIP is objective and measurable. And make sure it is reasonable compared to past performance and other people. It is not reasonable to "fail" you on your PIP if you are writing the same number of lines of code, or creating fewer bugs, than you were when you were getting "exceeds expectations" ratings. Also you shouldn't be getting significantly different PIP measures from the other people in the same circumstances.

Given the situation, I am considering accepting severance if offered, as I feel I may no longer be wanted within the company.

Smart idea, but be proactive. Start looking for your next role.

Would it be advisable to request a reference from my direct manager before the PIP begins?

Before, during, or whatever it is very advisable. It sounds like they do not agree with upper management about your performance. Additionally there may be other coworkers that feel the same way. Both offer to provide them with a good reference and ask them for one yourself.

Same story in the company I worked for last year.

Most of the employees were put on PIP without any strong reason, and several of them were performing really good. A former colleague of mine was terminated immediately last month. I believe it to be a global issue as the overall market is down and companies are finding a safe way to reduce their workforce. Maybe they fear AI.

As you said, many of your performance reviews were good, i highly doubt if they still want to keep you in the team, even though you are an over-performer as you said.

I highly advise you to keep looking for other opportunities beforehand. Good luck!