The financial services industry is experiencing its biggest transformation in history, and open source is the catalyst. From legacy COBOL systems to modern, composable building blocks, we're witnessing a fundamental shift in how financial infrastructure is built and developers are now leading the charge. In this talk, David Okononfua, explores the intersection of code, digital finance, and collaborative development. You'll discover how Nigeria processing $1.68 trillion in mobile money transactions and ranking #2 globally in crypto adoption—is uniquely positioned to lead this revolution. Learn from real-world case studies including Apache Fineract (serving 20M+ customers), Nigeria's new National Payment Stack, and open banking APIs like Mono and Okra. Whether you're building your first fintech app or contributing to global open-source projects, this talk provides practical insights on leveraging open source to democratize financial services and solve African problems at global scale. #OpenSource #Fintech #Nigeria #Africa #DeFi #Banking #APIs #Blockchain #FinancialInclusion #DeveloperTools #PaymentSystems #OpenBanking #Innovation #WebDevelopment #FinancialServices

1. Devfest Benin 2025
David OD Okononfua
Lead Frontend/Design Engineer,EasySpend
Code, Coins, and
Collaboration:
How Open Source
Shapes Modern
Finance

2. WHO AM I?
@Vinylchi @Vinyl-Davyl
● Lead Frontend & Design Engineer,
EasySpend
● Worked in fintech, AI, Web3 etc
● Google Summer of Code(GSoC)
alumnus
● Open source enthusiast / Super big
Chelsea fan 🔵

3. Why this Talk?
● How open source is transforming modern
finance, why it matters for fintech in
Nigeria/Africa, and how you can
contribute/collaborate.
● Angela Strange: “Imagine that financial
services were built with software-building
blocks like Lego… this is the potential of
open source coming to financial services”
collaboration (open
source)
code (software)
coins (digital finance /
crypto / tokens / fintech)

4. The Traditional Finance
(TradFi) Landscape
● Before now, legacy banking systems were
built: monolithic, on-premise, closed code,
high cost and notoriously hard.
● Open source will catalyze the financial
services industry’s biggest evolution to
date. This evolution will shift the power in
this $25 trillion industry from business
executives to developers.

5. Fintech & Crypto Explosion
Source According to
Boston Consulting
Group and Elvandi

6. Challenges in
African/ Nigerian
Fintech
● Compliance & security
● Legacy infrastructure, regulation,
trust, cost of build/ops
● The “unbanked/underbanked”
opportunity

7. Enter the Open Source
Open source refers to software whose source
code is made publicly available, allowing
anyone to view, modify, and distribute it.
It is developed collaboratively within a shared
community and is freely reusable under
licenses that promote transparency and
innovation.
Why open source matters for finance: cost
reduction, faster innovation, composability,
trust.

8. Open Source +
Finance. What’s the
Shift?
Open-source primitives for
Banking Infrastructure
● Modular Architecture
● Shared Building Blocks
● Community Contributions
Product Layer
Banking Products: Savings, Lending, Cards
Middleware Layer
Risk & Compliance: KYC/AML Modules
Auth & Security: OAuth, encryption protocols
Foundation Layer
Core Infrastructure: Ledgers, Payment Rails,
Identity Verification
Experience Layer
User Interface: Mobile apps, dashboards

9. Case Study(1/2) – Open
Source Primitives in
Fintech
● Mifos Initiative (open source core
banking), openMF on github.
● Okra(closed): Open Banking APIs, KYC
verification services, payment
collection, balance validation
● Mono: Open Banking, Statement
collection, Direct debit

10. Case Study(2/2) – Open
Source Primitives in
Fintech
● MOJALOOP(Open source, payment
switch): Lowers cost to build, maintain and
modify inclusive instant payment systems.
● PayStack: Payment Processing Layer
● OnePipe: Banking as a Service
● National Infrastructure: Nigeria's
NPS(National Payment Stack) connecting
all players

11. My Open Source
Journey: Concerto,
Playground & Beyond!
My open source journey, Building Concerto
(business schema language & runtime) and how it
is used by DocuSign and a Playground for
Markdown Template.
🔗 https://github.com/accordproject/concerto

12. “Be like water: Empty
your mind, Be
formless, Be
shapeless, Flow”
Bruce Lee
Devfest Benin 2025

13. Coins & Open Source –
Blockchain / Crypto
Intersection
● DeFi narrative: open,
composable, trustless
systems.
● Open source underpins
crypto (smart contracts,
open standards, DeFi)

14. Compliance, Security &
Open Source
● Risk: open source doesn’t mean
insecure; need governance,
audits, secure code, compliance.
● Compliance frameworks still
apply even open-source tools
must meet GDPR, SOC2, ISO
27001, PCI-DSS, etc., depending
on use.

15. Benin 2025
Collaboration Matters:
Africa/Nigeria & Open
Source Fintech
Opportunity
Africa is uniquely positioned:
leapfrog legacy tech, large young
developer base, increasing
crypto/mobile money adoption.
“Developers will not only be
creators and sellers of these
primitives, they will also be the
buyers.”

16. Football Analogy →
Engineering Comparison
● “Cole Palmer; picks right moment,
forwards attacks, adapts quickly” →
“An open-source library picks the
right moment, forwards innovation,
adapts quickly.”
● Legacy systems are the John Terry
of software “New tools may be faster
or more flexible, but the Terry of your
stack brings the reliability you fall
back on when everything else fails.”

17. Architecture of Modern Finance and Open Source
Compliance &
Security Layer
Open Source Dev
Tools & Libraries
Layer
Financial APIs /
Integration Layer
Open Source
Infrastructure Layer
(Base Layer)
Fintech Application
UI
End User
Linux (OS for most
banking servers, cloud
infra)
PostgreSQL / MySQL
(core databases for
fintech apps)
Kubernetes / Docker
(container orchestration)
Nginx / Apache (web
servers)
React, Vue, Next.js →
Frontend frameworks
Express.js, FastAPI,
Spring Boot → Backend
frameworks
Kafka, RabbitMQ →
Messaging queues
Redis → Caching
Payments: Paystack,
Flutterwave, Stripe
Identity: SmileID,
Passbase, NIN/NIMC
lookups
Banking APIs: Mono,
Okra, Stitch
KYC / AML checks (built
with open-source ML
libraries)
OpenSSL (TLS, encryption)
HashiCorp Vault (secrets
management)

18. What’s Next in Open
Source + Fintech
● Embedded Finance
● Open Banking
● Open-Source Primitives,
● DeFi’s push,
● Developer-First Fintech.
“The financial sector is on the brink
of transformation…”
Editable Location

19. How You in This Room
Can Participate
● Contribute to open-source
projects.
● Use open-source libraries in your
startup or engineering work,
rather than reinventing the wheel.
● Collaborate with global
communities
● Think local (Nigeria/Africa)
problems + global scale

20. “Think global, Build Local:
Code (your role) +
Coins (digital assets/fintech) +
Collaboration (open source/community)
=
the new triangle of digital/financial
success.”
David OD Okononfua
Editable Location

21. Question?
David Okononfua
Devfest Benin 2025
@Vinylchi @Vinyl-Davyl

22. Devfest Benin 2025
David OD Okononfua
Lead Frontend/Design Engineer,EasySpend
THANK YOU!
Let’s build together, code
coins & collaborate.
@Vinylchi @Vinyl-Davyl

23. Editable Location
David OD Okononfua
Frontend/Design Engineer,EasySpend
Code, Coins, and Collaboration:
How Open Source Shapes
Modern Finance