Satyendra Singh .
Engineering Leader · Fintech & Payments
I architect secure, high-throughput payment systems that power millions of transactions daily — from ISO 8583 protocol engines and EMV card processing to UPI infrastructure and soundbox platforms. 10+ years of fintech engineering leadership from Mumbai, India.
10+
Years in Fintech
10M+
Daily Transactions
20+
Engineers Led
6+
Products Launched
Architecting fintech
for the next billion users
Engineering leader in fintech & payment systems based in Mumbai, India. 10+ years at a single company — growing from intern to Engineering Manager, architecting payment systems that now process 10M+ transactions daily.
I lead teams of 20+ engineers, set architecture standards, mentor senior engineers, and translate complex payment ecosystem requirements into PCI-DSS-compliant systems with five-nines reliability.
Education
Master of Computer Applications
2013 – 2016
Bachelor of Computer Applications
2010 – 2013
10M+
Daily Transactions
99.99%
System Uptime
20+
Engineers Led
12+
Products Shipped
Payment Systems
ISO 8583 · EMV · UPI · Contactless
Security & Compliance
PCI-DSS L1 · HSM · Tokenisation · 3DS
Protocol Mastery
MPOC · CPOC · Multi-Acquiring · DCC
Engineering Leadership
20+ engineers · Architecture standards
10+ years building
payment systems
10+
Years
7
Promotions
10M+
Daily TXNs
20+
Team size
Engineering Manager
NowJul 2025 – Present
Leading multiple engineering squads of 20+ engineers across card payments, UPI, and emerging payment technologies. Setting technical direction, driving architecture decisions for next-generation payment infrastructure, and owning delivery of critical payment platform features.
20+
Engineers led
10M+
Daily TXNs
3
Squads owned
Engineering Lead
Jul 2023 – Jun 2025
Led the soundbox voice notification platform and multi-acquiring routing engine. Scaled to 100K+ merchant devices. Introduced ML-based routing that improved approval rates by 2.5%.
Senior Tech Lead
Oct 2020 – Jun 2023
Architected MPOC/CPOC SoftPOS platform and DCC system covering 180+ currencies. Built HSM integration for cryptographic key management. Led AWS cloud migration.
Tech Lead
Jul 2019 – Oct 2020
Built the ISO 8583 transaction switching engine from scratch — high-performance Java/Spring Boot with sub-millisecond message parsing.
Senior Software Engineer
Jul 2018 – Jun 2019
Built core EMV card processing — chip & PIN, CVV/CVC, 3D Secure, NFC contactless flows, and magnetic stripe fallback.
Software Engineer
Apr 2016 – Jun 2018
Backend card payment services — auth flows, settlement reconciliation, merchant onboarding APIs. Visa, Mastercard, and RuPay integrations.
Software Engineer Intern
Feb – Mar 2016
Fresh out of MCA — built payment dashboard and transaction monitoring tools. Two months led to a full-time offer and 10+ year journey.
Fintech systems powering
real-world payments
From ISO 8583 protocol engines to UPI infrastructure — deep technical expertise across the full payment stack, architecting solutions that process billions of rupees in transactions daily.
ISO 8583 Payment Protocol Engine
High-performance ISO 8583 message processing engine for real-time financial transaction switching. Handles message parsing, bitmap construction, field validation, and routing decisions with microsecond-level latency across 10M+ daily transactions.
Card Payment Middleware Architecture
End-to-end card payment middleware supporting Visa, Mastercard, and RuPay. Full EMV chip & PIN processing, NFC contactless, and magnetic stripe fallback with PCI-DSS Level 1 compliance across the entire transaction lifecycle.
Soundbox Voice Notification Platform
Architected the soundbox platform for real-time payment voice notifications on merchant devices. Device management system, audio rendering pipeline, and push notification infrastructure deployed across hundreds of thousands of merchant terminals.
MPOC / CPOC SoftPOS Platform
Merchant-Presented QR (MPOC) and Consumer-Presented contactless (CPOC) payment solutions enabling NFC tap-to-pay on standard Android smartphones. EMVCo-compliant SoftPOS eliminates need for dedicated POS hardware.
UPI & QR Payment Infrastructure
Full-stack UPI payment integration for merchant checkout and P2P transfers. Deep-link flows, dynamic QR generation, VPA validation, and NPCI gateway integration with real-time transaction status and automated settlement reconciliation.
Dynamic Currency Conversion (DCC)
Complete DCC lifecycle: BIN-based cardholder currency detection, live FX rate presentation, explicit cardholder choice flow, and markup calculation. Integrates with Visa VPAS and Mastercard MCR programs across 180+ currencies.
HSM Key Management & Cryptography
Hardware Security Module integration for cryptographic key lifecycle management. Key generation, injection, rotation, and destruction for PIN blocks, CVV2 generation, EMV key derivation, and 3DS transaction signing in PCI-compliant environments.
Multi-Acquiring Transaction Routing
Intelligent payment routing engine across 5+ acquiring banks using real-time cost analysis, success rate history, geographic rules, and ML-driven decisions. Automatic failover and load balancing consistently achieve 98%+ approval rates.
Full-stack payment engineering expertise
A decade of hands-on experience across protocols, infrastructure, security, and team leadership in fintech
Backend & Frameworks
Frontend & UI
Payment Protocols
Payment Domains
Infrastructure & DevOps
Security & Compliance
Leadership & Process
High-Performance Systems
Sub-millisecond transaction latency at 10M+ daily transaction scale with 99.99% uptime SLAs
Security-First Architecture
PCI-DSS L1 compliant systems with HSM cryptography, tokenisation, and end-to-end encryption
Cloud-Native Scalability
Kubernetes-orchestrated microservices on AWS with Kafka event streaming and horizontal auto-scaling
Engineering insights
Deep dives into payment systems, ISO 8583, EMV, and fintech architecture — coming soon.
Let's work together.
I'm selective about the projects I take on. If you have something interesting in the payments or fintech space, let's talk.
Made with ♥ by Satyendra Singh
Schedule a Call
30-minute session · IST timezone