Monzo Insider Ep1 - Instant Spending Notifications

(Naji Esiri) #1

Ever wondered how spending notifications make it to your phone within seconds of paying for something with your Monzo card? How do we automatically categorise your spending? What’s the deal with the elusive ‘Easter egg’ emojis?? Tim Chung sat down with Matt Heath, an engineer from our Core team to find out!

Got a question for Matt or the team on the topics covered in this episode? Continue the discussion here.

Got an idea of what you’d like to discover in the next instalment of Monzo Insider? Share your suggestions below!

The Monzo Current Account Preview
Community Digest 16/06/17
(Alex Sherwood) #2

Slightly off topic but I’m really pleased to see that Monzo had Tim create this video, after he had a series of equally sublime videos about his experience as a Monzo user a while ago.

This seems like a great way to give upcoming videographers some exposure, as a reward for producing their own Monzo related content :heart: [insert hot coral heart here].


This is a great short film really informative​. Also the tech guy speaks English (not just tech speak)… not many of those arou :wink: keep up the great work

(Brexit Day Is Gonna Be Shamayzing.) #4

Good video but I wanna see hardware, server rooms and all that kinda stuff :sunglasses:

(Indy Puaar) #5

awesome idea and great pilot episode. Would have loved to see all the processes involved in the backend to getting the instant notification to the users phone.
Would love to see an episode of future developments and sneak-peak features into the current account. That’s what being an insider is all about :wink:

(Matt Heath) #6

Thanks @indypuaar, glad you enjoyed it! If you’d like some more detail on the backend processes involved when you use your card there’s an explanation of this (with some sequence diagrams) in a talk I presented at QCon earlier this year: Diagrams are about 40mins in! :nerd:

(Matt Heath) #7

@Danny alas the vast vast majority of the servers we run are in the cloud :cloud: by which I mean they are “virtual” and run in datacentres which Amazon operate, so no cool looking rows of servers :cry: We do have a small amount of equipment in the physical world which is used to connect us to various payment schemes such as MasterCard and the Faster Payment network in the UK. We’ll see what we can do on that front :wink:

(Jolin) #8

Are these required to be on-site (for security/access reasons?), or could you choose to locate them in a data centre if that worked out better logistically?


I think the MasterCard connection has to be on site and the rules are real strict as to what room they can be in and how far they are from the nearest tree :wink: They physically bring their cables to your secure premises for direct connection to their network.

(Matt Heath) #10

@jzw95 @anon44204028 for our infrastructure we don’t require anything to be on-site, if by on-site you mean our offices! We’d far rather run everything in secure facilities :smile:

We need two physical locations for MasterCard et al to deliver fibre to and connect us to their network :satellite: so that in the case of one of them failing (due to network/power issues :zap:) we still have a backup. In our case these are two secure co-location facilities :lock: which are geographically separated, with redundant networking equipment, that we run in an active-active configuration.

More info here (slide 45 onwards!):


Thanks Matt. Yep, we had a good presentation on it at one of the Open Evenings. By on site I mean a physical location rather than on the cloud.

(Alex Sherwood) #12

I’ve tried to guess this before but it would be good to hear from the team how Monzo decides which category to assign transactions for each merchant to? i.e. when I buy something from Starbucks, how does Monzo know to set the category to Eating Out?


Interested to hear the answer to that one. I assume that it is from the Merchant Category Codes that MasterCard and Visa send with the transaction data.

(Brexit Day Is Gonna Be Shamayzing.) #14

I would have thought that some might come from the tags on Foursquare?

(Matt Heath) #15

@anon44204028 guessed correctly :medal_sports: the initial automated system takes the “merchant category code” (MCC) we receive from MasterCard and maps this onto one of our categories. After this we may change a merchant if it’s been incorrectly assigned, but I think that’s relatively rare.

Custom Categories - 1
How does a business add an emoticon for mobile notifications after a transaction?