https://www.gov.uk/redundancy-your-rights/redundancy-pay
To quote:
"half a week’s pay for each full year you were under 22
one week’s pay for each full year you were 22 or older, but under 41
one and half week’s pay for each full year you were 41 or older
Length of service is capped at 20 years."
And also it's pretty shit because it's capped, so for most software devs it won't be anywhere near what their actual salary was:
"If you were made redundant on or after 6 April 2023, your weekly pay is capped at £643 and the maximum statutory redundancy pay you can get is £19,290. "