Help!!! Some ideas about CornerStone OnDemand SWE

Hi Guys, this is my first time to use this platform to ask for help and suggestions! Thanks! This week I got a verbal offer from CornerStone OnDemand for Software Engineer in one of Reporting & Analytics. 1) Actually I think I did good job during the whole interview process, I meet three teams of them… (Cloud SRE - > Search team -> Analytics) and they really like me and want me sign the offer. And I think I am ok with this current Offer number in LA area (what do you think?), but what I am concerning their tech stacks and the project they are doing and my growth. Weather CornerStone has latest cutting- edge tech regarding to Saas and cloud based IT company? As far as I know for the search team is using Kafka and elastic search to provide search feature(I am really interested in Data processing, Data pipeline, Kafka, Spark, elastic search… scale distributed microservices.) but they think the Analytics has more space to help me grow… since they only have one principle eng and HM in my specific team will be my mentor. And both search team and analytics do such similar things, but analytics more focus on data analysis and data visualization. Does any one know about CornerStone and the teams? I am worried about if they are using latest tech for new project Or just update code for legacy…. Can someone give me more details about this (I schedule a call with my HM, I will ask him about this). 2) During the whole interview process, I am really impressed by their culture. Everyone looks nice and willing to help. And to help you solve the problem and walk you through together. And they show their interest and like on me trying to compete everything other company provide… I think if I finally sign with them this will be a main reason… But now, they push me to sign the offer and cancel my uber onsite…. I don’t have much experience about this… (I think if uber give me offer…I will go) how to negotiate with my CornerStone HR. I have already tell him everything. Thanks for someone answering my question! Appreciated it! 😊