My understanding is (mind you this is from readings years ago) that the cert after the CCNA (i.e. CCNP) are increasingly difficult. Not sure they're particularly useful for employment as a developer, but for Network engineers I imagine so.
I remember a story about what I think was CCNP. Cisco had you come down to their test lab, set up everything they told you to set up according to constraints given, and then go back home. Part two involved them changing things to cause failures or degradations before you came back, then you had to diagnose and fix it to pass part two.
I hands-on practical test like that should be part of every exam, but it's expensive and time consuming.