FDIC insured regardless of the amount and only locks it up for 30 days. 30 day and 1 year is the same rate. I'm finance director at a large nonprofit and we use these all the time for temporarily placing cash and keeping it insured.

Are higher on the short end and aren’t subject to state taxes?

buying the CD's through my regular bank (Cap One). For me, the rate difference does not justify making it less simple. And we're not talking huge CD's either. Right now, I'm getting about 5%.

and way more liquid than a CD. If you want a little better rate and don't mind tying up your money for longer (which sounds true if you're looking at CD's), I'd look at i-bonds over a CD from a bank. But to your basic question, laddering your short term investments is an overall good idea. I've typically seen it as taking the money you have to invest and dividing it into 5 equal shares. Use those to buy a 1 year CD, a 2 year, a 3 year, a 4 year, and a 5 year. Then when the 1 year matures, reinvest it in a 5-year. Ditto with the 2 year, etc. After four years, you have all your money in longer term CD's, but always have 20% of it maturing that year so you're not eating big penalties if you need to withdraw some.

Obviously, that doesn't lock in your rate, but has the benefit of liquidity.

There are better materials you could use to construct a ladder