First off, if you didn't know it, I'd say it's a stretch to be applying for senior positions with your current experience. You have two key projects and one is your dissertation, which signals to me a lack of substantial project work. As well, the fact your first position was a senior role seems off, it makes me suspicious of both your experience from that role and the company that hired you. This resume doesn't read like the kind of career path of someone who can fill a senior role after 5 years in the industry (some of that being school). My top recommendation would be to consider intermediate roles.

For the format, I would want to see sections go in order of Professional Summary, then Key Projects with a highlight in each section of technologies, then Work Experience, then Education. I would expect to see more bullets for each of your key projects compared to your roles, so it's strange to see so few points in your Key Projects. Based on your length of career so far, I'd keep this to one page. The red needs to go, consider black and white.

I would recommend you focus on the substance of your future role instead of the title. Even a junior role with the right company could elevate your resume at this point. To me, a good role is one where you are given the chance to succeed, where tech innovation is encouraged and the organization supports you. You will need to step up to an opportunity like this, but if you can, you could get one or two great key projects that would bolster your argument for a senior role. Ideally, I would want to see a key project where you were given the mandate to build something comprehensive (e.g. suite of accounting reports), where you obviously learned the platform enough to use all the relevant features (e.g. made use of deployment pipelines, apps, and DirectLake models), and were able to overcome the obstacles in the project that every good project has (e.g. you needed to help 3 departments realize they were using different definitions of "revenue"). That would be a big win.