I bought UX303UA Zenbook back in June 2016 for £800. It's meant to be be a temporary laptop to be used for 1-2 years max.
Although it's quite cheap it had very good spec especially for 2016: i7-6500U @ 2.5Ghz and 12Gb RAM with fair 4-6hours on single charge, just 1.2kg. It was a significant improvement from previous Zenbook with i5 and 8Gb memory. RAM is especially critical for java developers, especially for greedy Android tools.
Even now, in 2020 this spec isn't bad at all. It's still possible to get a similar device bus slightly cheaper. Having said that I was thinking to add more memory so I can continue to use laptop comfortabily. Unfortunatelly, all websites and official sources say it's impossible - the max is 8(in the slot)+4(soldered).