How do new faculty members in the UK start their career without startup grants?
Research grants for new academic staff are offered competitively by the various research councils, depending on your subject area.
You can learn about the various research councils and what grants they operate through the web site for Research Councils UK.
For Computer Science you should be eligible for an EPSRC New Investigator Award, however the competition is fierce, so you should be sure to seek the advice and support of the research office of your University who can assist you in writing a successful grant proposal.
Some Universities, as noted, do offer their own support for new academics, but irrespective of funding available locally there is national funding, and also perhaps one might also look at European Funding for new researchers whilsts the window of opportunity remains open.
For an ambitious and promising researcher the position is not necessarily as pessimistic as you might feel.
In my experience, startup packages for Lecturers in the UK are much smaller than for Assistant Professors in the US. That said, I have never heard of a Science/Engineering School in the Russell Group offering no startup funds.
My School would typically:
Guarantee £30,000 contingent upon the Lecturer applicant applying for a £15,000 Royal Society Research grant (if the application was not successful the school would provide £30,000, but if the application was successful the school only provided £15,000) These grants have a very high success rate.
Guarantee funding for a 3 year Phd studentship
Guarantee "research" computers for the Lecturer and PhD student
The school also had a small amount of internal money for running pilot experiments (applications up to £5,000) conditioned on a large grant proposal at the end and conference travel (applications up to £1,000) conditioned on presenting work. These could be applied for every other year. New lecturers were given a boost to their application scores for their first 3 years.
The school also could recommend new Lecturers for money from the University (up to £25,000). They could only recommend only person per year and the money was somewhat competitive.
If the new Lecturer was successful everywhere (which is not too difficult), they could expect £67,000 and a PhD student. The school would also make sure there was suitable lab space with furniture. In the UK, you are also paid on a 12 month contract so there is no need for summer salary.