Use Microservices & APIS to divide & conquer your Legacy Systems

1. USE MICROSERVICES & APIS
TO DIVIDE & CONQUER
YOUR LEGACY SYSTEMS
Sotiris Nossis (CEO)

2. A GLOBAL FINTECH SOLUTIONS LEADER
• PC is a payments expert helping some of the largest financial institutions with its core expertise
• Is now helping Banks, Fintechs, ACHs worldwide in their digital transformation path
• Has built hundreds of legacy projects in the past 30 years but now is a microservices and APIs
fanatic
• Applies the “APIs first” project development dogma. We even built our own API platform for Banks

3. Countries with Existing Clients
GLOBAL REACH
Clients
50+
Countries
20+
aplonAPI
2 Nigeria
3 Cyprus
5 Portugal
1 Colombia (banks, Gov, Fintech HUBs)
Mostly EU, US and AfricaaplonCASH
3 Corporates in Greece
Others
40 banks & fintechs in US, Asia, EU

4. Develop &
Deploy
Digital
Growth
UX/UI
Design
ONLY CUTTING EDGE SOLUTIONS &
SERVICES
Solutions Services
Product
Blueprint

5. RECENT DISTINGUISHED PROJECTS!
HELLENIC
BANK
ARCA
NETWORK
DIGITAL
ONBOARDING
CARDLINK
Best Digital Initiative
award at the Banking
Technology Awards 2017.
5-star rating, in the
Configo Financial APIs
Index.
Nigeria’s 1st Private ACH.
We created the complete
Operational Blueprint &
built a FinServ 2.0, Open
Banking ready, API
powered system
Mobile application for the
end-to-end Digital
Onboarding, of new
Banking Customers,
including ID document
digitization & validation
Built a card processing
portal that supported their
3X growth in three years,
servicing 300.000 POSs,
250.000 Merchants and
handling over 200 TRXs
per second
Award Winning Ground Breaking Digital First Scalable & Robust
WE DELIVER THE FINTECH FUTURE
TODAY

6. OPEN BANKING
REDEFINES
FINANCIAL SERVICES
The financial industry exposes and
consumes APIs to reshape the customer
experience.

7. THE PROBLEM - the speed divide
• The world is changing – e.g. PSD2 in EU, Open banking
initiatives across the globe, fintechs & challenger banks.
• Everything is changing to meet the needs & expectations of the
customers that cannot be satisfied by the legacy systems and
structures

8. Monolithic or even
tightly integrated SOA
stacks can’t follow the
pace. We need a
different structure.
THE CAUSE – inelastic structures

9. Use microservices
architecture & APIS to
split an application into
distinct business rule
components that
support unique bits of
functionality and can
be managed by a
single team.
THE SOLUTION – divide & conquer

10. WHY USE MICROSERVICES
• Each microservice is developed using the most fitting
technology
• Phased implementation helps escape complete rewriting
• Small, autonomous teams allow for better communication
• Independent deployment doesn’t require synchronization of
processes
• Elements can be scaled separately

11. ORGANIZATIONAL ASPECTS
• Teams are organized around business capabilities
• Small teams
• Focused on products not projects
• You build it, you run it
• Culture of automation & governance
• Decentralized deployment

12. TECHNICAL ASPECΤS
• Exposes and consumes APIs to communicate
• Run on its own process
• Isolates faults
• Is stateless
• Deployed and Scaled independently
• Own its data

13. ARCHITECTURAL ASPECTS
• Uses API gateways
• Bounded context
• Single responsibility
• Is polyglot
• Choreographed
• Smart endpoint and dumb pipe

14. OPEN BANKING CREATES
TWO MAJOR TRENDS
The API
Publishers
The API
Consumers

15. FINANCIAL SERVICES APIs EVOLUTION
2018 2019 2020
APIs in EU are
pressing priority
The rest of the
world follows
Open banking
everywhere Publishers become
Consumers too
New players
emerge
Everyone now
consumes APIs
Consumers become
Publishers tooAPI
Consumers
2021
API
Publishers
Banks discover
3rd parties

16. DECOMPOSING A
MONOLITHIC APPLICATION
CASE STUDY
1

17. DECOMPOSING A MONOLITHIC APPLICATION
– the problem
• A three tier monolithic application (Spring MVC, Java) grew rapidly
(three years) from a reporting system to a large portal
• Its Transaction processes were growing 100% per year
(5000TRX/min)
• It was 600 MB of code, 1 TB data, Hundreds of processes
• Its user base was to grow to a few millions in two years
• It was constantly changing and that was proving to be too expensive
and unmanageable (long releases, system down too often for
updates).

18. DECOMPOSING A MONOLITHIC APPLICATION
– the problem

19. DECOMPOSING A MONOLITHIC APPLICATION
– How
• Identified autonomous processes and gradually separated them one by one
from the original application
• Created completely independent services for: Traces, charts, logging, vertical
services for different user segments, Batch processes subsystem)
• Used different DBs (mongo, Elasticsearch) to suit different purposes
• All new processes exposed APIs to communicate with the rest of the modules
• Used cloud services to deploy one by one the services
• The original monolithic application was shrinking month by month

20. DECOMPOSING A MONOLITHIC APPLICATION
– How

21. DECOMPOSING A MONOLITHIC APPLICATION
– Benefits
• The original monolithic application shrunk to a medium size project
• Deployments were very often (even once a day) very short (few seconds) no
down times, no conflicts
• Code was much smaller, cleaner and teams were more comfortable to work with
• Communication was cleaner, APIs everywhere
• Demanding processes were scaled independently
• UI changed to more eye candy tools for user facing processes
• The microservices culture was instilled in the project and all new services were
built autonomous
• We were now ready to respond to new requests in weeks

22. BUILDING A NEW SYSTEM
IN MICROSERVICES APIs
CASE STUDY
2

23. BUILDING A NEW SYSTEM IN MICROSERVICES
– the challenge
• A brand new system (API gateway) designed for high volume /
high availability and scalability
• It was designed in microservices so that banks could replace
some services with their own (eg. Authentication, developers
portal, AML, integration with core banking)
• We needed to also separate UI from API layers for the same
reason

24. BUILDING A NEW SYSTEM IN MICROSERVICES – the result

25. SOME CLOSING REMARKS
TO SEE THE WHOLE PICTURE

26. HOW TO
PUBLICIZE
YOUR APIs

27. HOW TO
MONETIZE &
MANAGE
YOUR APIs

28. SOME MORE THINGS TO CONSIDER
• You need Evangelists to Instill the right culture
• API Consuming applications & developers are your new VIP customer
• You need proper tools to manage and deploy the APIs
• The engineering effort may set you back
• Inter-service communication creates more errors
• Testing and monitoring may be daunting
• You will have to adopt DevOps

29. APIS & MICROSERVICES
ARE RESHAPING
THE FINANCIAL INDUSTRY
nossis.sotiris@paymentcomponents.com
SOTIRIS NOSSIS,
CEO, PaymentComponents