Saint HighLoad++ · September 22, 2022
Channel. Product. Platform.
How the approach to building Tinkoff's mobile bank evolved
/ Channel. Product. Platform · Saint HighLoad++ 2022
How the approach to building Tinkoff's mobile bank evolved
How the approach to building Tinkoff's mobile bank evolved
CTO of the mobile bank, online acquisition and more
I curate our System Design and Troubleshooting interviews
Who this talk is for
Why scale development at all?
How do you do it evolutionarily, without dropping business work?
Which target topology should your teams aim for?
How do you balance platform and product development?
The mobile bank as channel, product and platform
2006 — the company is founded, 2008 — internet bank
2011 — the mobile bank appears
2015 — the mobile bank is the top product
2019 — a platform, 2022 — what comes next
2006–2011: from postal mail to the first app
How it all started (2006)
Credit cards only at the start
Direct sales by postal mail
Customer contact through call centres
The mobile bank appears as an additional channel
Basic services were picked for the launch
The first version was built to order by contractors
Requirements were written screen by screen
Planning ran as app versions with scope fixed up front
2015: development moved in-house
The mobile bank as a product
Customers: retail bank, business bank, insurance
One shared IT team of ~20 with shared prioritisation
Large releases roughly once a quarter
A monolithic app and the Mother API
While there are few products and the team is small
There were a few main products taking the resources
The team was small — around 50 people by 2019
Priorities could still be managed by hand
The focus was on extending functionality
2019: verticals, teams and architecture
The group's growth and the IT landscape
2006–2019: from monoline bank to SuperApp
Verticals: retail, SME, investments, insurance
…the mobile operator and non-financial services
And platforms: data, ML, origination, infrastructure
Different apps and a shared core team
SuperApp and the business bank app
The investments and mobile operator apps
One mobile core team serves them all
And that team becomes the platform team
The new team structure
Banking products, Payments, Insurance products
SME products, Invest products, NonFinancial Services
Platform teams: Release, Platform, Design
…Excellence, Performance, Reliability
Three states of the same diagram
Organizations design systems that copy their communication
Before: one shared team over a layered architecture
After: autonomous teams with their own domains
Target: their own modules and a modular architecture
Release trains and the engineering culture
Teams have to be able to work autonomously
Delivery managers roll out the Kanban process
Automated testing is mandatory for new features
Fitness functions run through Danger in CI/CD
Interim results
Plus smaller releases in between
Processes documented, owned by the team and the DM
Platform teams rolled out modularisation
Set up mobile SRE and optimised performance
2022: end-to-end delivery and governance
The business wants better end-to-end value delivery
The software got too big for one team
Delivery slowed down as a sustained trend
Business services rest on scattered lower-level ones
Each trigger has its own set of symptoms
Teams spanning SuperApp, APIs and Backends
End-to-end metrics: TTM, lead time, cycle time
Work on both downstream and upstream
From «fetch your own data» APIs to a mobile BFF
And towards read models built on an event stream
Platform technical governance
What a team is and what attributes it must have
The development, deployment and operations processes
The rules show how healthy the teams are
Metrics: productivity, quality, flow
The questions I promised to answer
The questions I promised to answer
At the start there was no in-house mobile development at all
The app became an advantage — development moved in-house
Products multiplied — a platform became necessary
Cross-cutting teams demanded technical governance
Take this experience and map it onto your own situation
Why scale, how to do it evolutionarily, which topology, and how to balance platform against product
From the talk's closing slide
The written version of the talk — bit.ly/mobileBankEvolution
All recommended materials are listed at the end of the article
polomodov.tech
All slides and links are in the Telegram channel
Alexander Polomodov, Technical Director & Fellow, T-Technologies
@book_cube