My advice would be to push as hard as you can to change the culture, or you'll be drowned. Engineers will not make it a priority to fix anything that causes outages because they will be evaluated on feature velocity, not uptime.

If you can make the company culture focus on uptime, or get engineers involved in remediation, then you'll be better off.

If you can't do that, try to at least push for the Google model: The engineers are responsible for uptime of their product until they can prove that it is stable and has sufficient monitoring and alerting, and then they can turn it over to SRE, with the caveat that it will go back to the engineers if it gets lower in quality.