Architecture at Scale
How architectural decisions are made at a large fintech
Slide contents
1. Architecture at Scale
How architectural decisions are made at a large fintech
2. Agenda
Architecture to practical tools
Why architecture must scale
Booch, Kruchten, levels
Software: RFC, ADR, groups
Solution: SLA, contracts, debt
3. 01. Why Scale
The context of a large fintech group
4. Why architecture becomes a discipline
Meeting agreements stop scaling
12M+ customers
Multi-product ecosystem
Team growth — onboarding knowledge
Distributed teams — decentralized decisions
5. 02. What Is Architecture
The definitions we rely on
6. Architecture = significant decisions
Trajectory & boundaries
Booch: significant system decisions
Significance = change cost
Trajectory — system direction
Boundaries — costly to revisit
7. 03. Three Levels of Architecture
Software · Solution · Enterprise
8. Three architecture levels
Software · Solution · Enterprise
Software — team; IDE, UML
Solution — department; wiki, boxes & arrows
Enterprise — company; ArchiMate
Themes: patterns → options → strategy
9. Enterprise architect is a mythical role
Where each one grows from
Software architect — grows from developers
Solution architect — from analysts, per project
Enterprise architect — origin unknown
10. 04. Software Architecture
RFC, ADR, and working groups
11. Before
Typical software-level pain
Verbal decisions get forgotten
Teams reinvent their stacks
Infrastructure code duplicates
No design-review language
12. What we introduced
Light process, heavy effect
RFC — public discussion
ADR — short record: context, decision, consequences
Working groups by domain
Tech radar + review gate
13. 05. Solution Architecture
Contracts, SLA, and tech debt
14. Typical solution-level pain
Many services, no rules
No SLA — consumers guess expectations
Weak APIs create consumer hacks
Tech debt reaches bankruptcy
Broken dependency can drop the system
15. Design belongs to those who build
Decisions documented, tech debt funded
Design owned by devs and analysts
Document conditions and trade-offs
Tech debt visible and funded
Core and platform teams
16. 06. Enterprise Architecture
The same process — company-wide
17. The same decision process, just wider
Unifying how IT decisions are made company-wide
One decision process, company-wide
Shared CI/CD and PaaS runtime
Tech radar for external technology
Doc standards and InnerSource
18. 07. What We Ended Up With
Conclusions and next steps
19. What works at scale
Culture beats tooling
Architecture = costly-to-revise decisions
Three levels need different tools/people
RFC / ADR make decisions visible
Working groups, contracts, SLAs create trust
20. References
Architecture models, fintech case
Patrick Kua — Scaling out architectural decision making
Kruchten — A Mature Discipline? (SEI, 2020)
Fundamentals of Software Architecture + Technology Strategy Patterns
ThoughtWorks Technology Radar v.22
21. Thank you!
polomodov.tech
All slides and links — in the Telegram channel
Alexander Polomodov, Technical Director & Fellow, T-Technologies
@book_cube