Earlier quoted context omitted.
100k USD is 75k GBP. Many junior developer roles in London will pay 50k. Some finance ones will pay 75k or more. 600k USD / 450k GBP is also definitely reachable for a senior developer at team leader level or comparable.
450k as a team lead? I’ve never heard of that. In itjobswatch.co.uk highest median salary for London is around 200k.
Also at this level you enter into a negotiation with the business stakeholders, compensation package is tailored to each profile and opportunity.