The Verdict: Not eligible
You do not need a working holiday visa: as an EU, EEA or Swiss citizen you can already live and work in Poland freely. If you want to settle, look at our naturalisation route.
There is no age limit, no quota and no rule that the work be incidental to a holiday. For a stay over three months, register your residence at the voivodeship office and you receive a certificate of registration of residence for an EU citizen.
Five years of continuous residence gives a permanent right of residence. Three years holding it, with stable income, housing and Polish at B1, opens recognition as a Polish citizen.