According to Sycamore a financial solution company in Nigeria the best banks in Nigeria in ranking order

Zenith Bank
Guarantee Trust Bank
First Bank
UBA
ECOBANK

But Sterling bank is a commercial bank which I think in no distant time can fall within that rank of the BIG FIVE if they can change one or two ways of doing things

One major area sterling bank needs to work on is their SMS and online platform like the OnePay and OneBank mobile app. These platform breaks down at the slightest ish to Nigeria network and customers traffic

Like the parable of Talents,the BIG FIVE BANKS are always adopting various strategy to remain top ranked. Sterling Bank needs to also Approach some better SYSTEMS ANALYST that will help them grow with their ONETALENT