Bank Excel. What banks count money.

[Brother]

A living person never encounters special programs that are used in banks. But I know that many people are interested in it. Today we will pour some coffee on the keyboard ... Uh, light on this question.

I have to apologize right away - there will be no screenshots. Those to which I have access, I have no right to show, and those to which I have no access - I want to see it myself The main thing to say is that in most cases these large systems are not painfully user-friendly.

All corporate systems are moderately (?) Ugly and extremely confusing. But the main ambush is quite different. The fact that there is no single information system in the bank. There is no single one.

There are several heterogeneous applications combined into a common information system with gaps of different widths. Sometimes it is quite successful, sometimes it is not successful. Each bank builds its own rake obstacle course based on assurances from sellers who are known to lie to their advantage.

The main thing that shocked me was that there is a conspiracy in the banking software market to "stay away from neighbors." Those. some companies produce software for processing card transactions, others - for all finances. There is also other auxiliary software, but this is the main watershed, and no one will release a program that would process both card transactions and manage finances. Do you do banking finance? So do it, do not meddle in card transactions. And vice versa.

But with each other, these systems are often able to be friends with varying degrees of seamlessness. Because they know about each other, and often immediately have the opportunity to connect.

Why the division has developed - I do not know, but here is how these systems are fundamentally different, I will tell you.

Automated Banking System (Core Banking System)​

I'll start with what I know worst of all Because my company does not do this.

In these systems, all bank liabilities-assets are taken into account and transferred. Not only money (both cash and non-cash, and in different currencies and all that), but also various financial things such as securities, and precious metals.

Let me remind you that the bank owns not only clients' funds, but also its own assets. The bank also conducts its internal kitchen in this system.

These systems have specific features.

Offline (mostly) mode of operation​

Those. they came in the morning - turned it on, turned it off in the evening.

No, of course, it all works around the clock, on servers. But the system is rigidly tied to banking days, to the bank's operating hours. We can say that there is a high proportion of interactivity, interaction with operators. Most of the information flow is generated by the actions of system users.

Let's say you came to deposit cash into your account (yes, now this is a thing of the past thanks to ATMs with cash-in), and then such a cashier enters this system and creates an incoming cash order. This very order has been created, it generates a number of events in this system.

But there are also automatic actions, and one must understand, quite a few.

Let's say that accrued interest is regularly recalculated, reports are generated, etc. And by the way, most often part of the system works around the clock to integrate with the card system.

Complex logic of calculations​

The bank has so-called. "banking products". This is a set of tariffs, limits, processing conditions, etc. Those. a deposit with some name "Loss" actually includes several algorithms for calculating commissions, limits, regulations for the storage and movement of funds.

And all these algorithms and rules can be quite confusing, this is the heart of the bank's business. It is necessary to do something magical with money so that there are more of them in banks than yesterday. If this does not happen - the bank is unprofitable, if it does - well, we will think that there is a profit. And for this you need to carefully invent and calculate everything.

Delay tolerance​

The operator went to lunch? It's okay, the document will hang unprocessed.
Didn't start the task of recalculating interest? In most cases, everyone will wait quite calmly for a few minutes, or even hours, or even days.
Did you receive a payment order? Well, let him lie down, the turn will come.
Well, everything is not so simple, of course, there are also regulations. But it cannot be compared with card systems.

Card systems​

The term is imprecise, but appropriate. This is the information system that accepts requests from POS terminals, ATMs, Payment Systems, Internet banking (not always), etc. In general, it works with everything related to cards or their analogs.

There is a little ambiguity about Internet banking: in general, Internet banking does not necessarily deal with cards. But if we talk about individuals, in recent years, it has almost always been about the fact that the user has a card (or token), and in this case, Internet banking normally cannot work without a card system, and therefore Internet banking in these cases tied specifically to the card system.

These systems are characterized by:

High availability requirements​

The time limit for processing a card transaction is a maximum of 30-40 seconds. If some of the participants did not meet - goodbye, the timeout has expired, the transaction is rejected. And during these 30-40 seconds, the request often runs half the globe (and even more), through many nodes in the network, is processed by several participants with their own internal kitchen, and arrives back at the terminal. Do not compare with the "9 to 6, Monday to Friday" mode.

24/7 work​

The bank is open from 9 am to 6 pm, and the ATM (and often a POS terminal) is open around the clock. Regardless of whether the bank clerks are at work, you should still be able to use the services of the bank.

And payment systems do not sleep at night either, they receive a lot of requests - both in connection with the actions of our customers in other people's terminals (someone used the card), and in connection with the logic of transaction processing. For example, you may receive a message about the need to make a calculation based on the past day (clearing and settlement - calculation and settlement). In general, there are many things that can come, this is just an example.

By the way, maybe there was some kind of automatic or recurring payment. This also happens around the clock.

High degree of autonomy, automation, load​

All such systems are very careful about their performance and ability to withstand the load. All this is impossible without the development of smart and fast algorithms. There is no place for a person in the transaction processing chain.

People here exist in parallel - for example, they set up all these algorithms, rules, limits. Or they manually handle situations that are generated by algorithms. For example, a suspicious operation has occurred - the algorithm has already made a decision and ran on. But an event was generated for the risk officer, which he must consider (if there is no automatic processing for this situation) and make a decision (for example, block the card).

During this time, the card system can already process several hundred other transactions. And generate several other events.

By the way, the performance of card systems is measured in TPS - transactions per second - the number of transactions per second. For some large banks, these indicators can reach several hundred or even thousands. Transactions. Per second.

Working with machines​

It is to these systems that all the numerous terminals are connected. And ATMs, and POS-terminals, and a number of specific devices (such as banking terminals - it's almost like a POS, but with a slightly different program, and are installed in cashier's offices at cashiers).

Imagine that a small bank can have a hundred ATMs and a couple of hundred POS terminals connected to its processing. All this needs to be constantly listened to, to maintain continuous communication with all this (if it is an ATM; the POS terminal only gets in touch from time to time).

The interaction of these two main systems​

The main thing to understand is that the card system operates with a part of those accounts that are also operated by the ABS. This means that they must certainly exchange information.

Here you have inserted the card into an ATM, you withdraw money. The card system needs to make sure that you have enough money to do this. But it may be that your card product contains some very complex logic for calculating the balance, and this logic is implemented in the ABS. This means that there are at least two options.

In the first, our card system should go to the ABS and clarify the balance. This means that the ABS should have a module that also works around the clock, and is ready to answer the question about the balance.

In the second variant, the card system should regularly (for example, once a day) receive information about balances or daily limits. And allow transactions within these limits. The complex logic of the calculation is in the ABS, but the card system must at least roughly take it into account in order to prevent overspending. But it can still happen For example, in the evening you make a purchase with a credit card, and in the morning the ABS, according to the regulations, removes the interest on the loan - and hop! - fly out of bounds. This can happen technically.

Conclusion​

In general, the bank has a very large park of programs, and no one, of course, uses Excel.
Oh, and I also found that I have already written on this topic, but from a slightly different point of view.

Write your questions in the comments!