Skyline of London Justin Solomon | CNBC

Much better, but far from being problem-free —most analysts describe the European banking system as "deleveraged and in a safer position" 10 years after the collapse of Lehman Brothers and the subsequent start of the global financial crisis. The failure of Lehman Brothers in 2008 roiled global markets. It was the fourth-largest U.S. investment bank and when it filed for bankruptcy on September 15, 2008, it led to an erosion of nearly $10 trillion in market capitalization in global equities in the following month. The collapse of Lehman unveiled that the bank had a huge problem with mortgage-backed securities — a kind of asset, that were in fact worth very little compared to their price. But, more broadly, Lehman's problems were almost every bank's problems. In Europe, banks that had also taken elevated risks struggled to get funding and many had to be rescued by huge bailouts from their respective governments. "European banks deleveraged and increased their capital ratios after Lehman, so they are in theory in a safer position than 10 years ago," Carsten Hesse, European economist at Berenberg told CNBC via email on Tuesday. "But in some euro zone countries such as Greece or Italy, non-performing loans are still very high, causing headaches and the profitability of some banks, including in Germany, is still very low," he added.

Non-performing loans are one of the biggest drags to bank profitability in Europe. A high-level of bad loans increases the liabilities pile on a bank's balance sheet. As a result, the lender will have to generate higher profits to offset those liabilities. In recent times, European bank's profitability have also come under pressure due to a lower interest rate environment, uncertainties surrounding U.K's exit from the European Union. A report from the European Parliament from last March showed the level of bad loans has somewhat decreased over recent years, from 6.4 percent in December of 2014 to 4.2 percent at the end of September 2017. "However, the current NPL level in the EU is still higher than in other major developed countries," the report from European institutions said. Daniel Lacalle, chief economist and investment officer at Tressis Gestion, told CNBC via email that there is plenty of work to do when it comes to non-performing loans. "European banks have been building core capital and strengthening their balance sheets. However, it has not been fast enough and challenges remain. Non-performing loans in Europe are more than double relative to all loans than in the U.S., exposure to sovereign debt and risky emerging economies remain too high and net income margins are very weak," he said. Apart from reducing bad loans, there has also been a big push for stronger regulation. Banks have been forced to increase their capital ratios, the European Banking Authority was established to oversee lenders and it conducts regular stress tests to ensure the banks are strong enough to sustain a crisis. George Magnus, former chief economist at UBS, told "CNBC's Street Signs" Wednesday that regulation is more "intrusive" now, which has made some parts of the financial system safer compared to 10 years ago. "Having said, whilst personally I think regulatory authorities around the world may be in a much stronger position to spot and save individual institutions… the clue to solve a systemic financial crisis is in the name systemic. Have we resolved the problems in the financial system and in the economic system that actually gave rise to this and previous crises? I don't think we have really done that," he said.

The problems that arose in the U.S., in particular at the Lehman Brothers, were not individual issues. The entire financial system took too much risk. "The challenges were extreme," Russell Downs, Partner at PwC and who was part of the team trying to clean up Lehman after the collapse, told CNBC. "We have had an awful lot to do, we have had hundreds of millions of assets to deal with," he said, adding that the former Lehman has managed to return over 44 billion pounds ($57.42 billion) worth of securities and assets to Lehman creditors. He, however, added that the environment is much calmer now. "The banks are smaller, they have got more capital so hopefully they will be better prepared to weather any financial storm that come," he said.

Where's the next crisis?

Ten years on, everyone is trying to understand where risks are mounting and forming the next crisis. "I don't think the next crisis is going to look like the last one, in the sense that the world isn't as leveraged as it was back 10 years ago," Jay Bryson, global Economist at Wells Fargo Securities told CNBC's "Squawk Box Europe" on Tuesday. While some number of analysts have pointed to China and its indebted system as the next crisis point, others have suggested that high-levels of global debt that currently stand at a record $247 trillion will be the kicking point; unrealistic stock prices as well as emerging economies have also been cited as potential starting points for the next crisis.