# Arshdeep Singh

> Backend engineer specializing in payments infrastructure and distributed systems. Sole owner of Paytm's Payment Gateway Notification Service; previously built payment orchestration and an ISO 8583 bridge across 14+ African markets at Airtel.

## Contact

- Email: adsingh.net@gmail.com
- LinkedIn: https://www.linkedin.com/in/adsinghnet/
- GitHub: https://github.com/adsinghnet
- Resume: /resume.pdf

## Summary

Arshdeep Singh is a backend software engineer with 4+ years of experience building event-driven, fault-tolerant microservices for fintech and payment systems at scale. He owns real-time SMS, WhatsApp, email, push, and merchant webhook delivery for payment, refund, settlement, and subscription lifecycles. Previously scaled payment orchestration to 300+ TPS across 14+ African markets and bridged REST to ISO 8583 for national financial switches.

## Key pages

- Home: /
- Work timeline and experience: /#work
- Engineering case studies: /#case-studies
- Interactive playground: /playground
- About: /#about
- Contact form: /#contact
- Resume PDF: /resume.pdf

## Case studies

- One Keystore, Two Merchants: /case-studies/one-keystore-two-merchants
- Speaking the Bank's Language (ISO 8583): /case-studies/speaking-the-banks-language
- Two Codebases, One Fallback Loop: /case-studies/two-codebases-one-fallback-loop
- From Polling to Pub/Sub: /case-studies/from-polling-to-pubsub
- Seventy Secrets, One Vault: /case-studies/seventy-secrets-one-vault

## Playground

- Webhook Signature Workbench: /playground/webhook-signatures
- Retry Ladder Simulator: /playground/retry-ladder
- ISO 8583 Decoder: /playground/iso8583

## Skills

Java, Spring Boot, Apache Kafka, Redis, MongoDB, PostgreSQL, microservices, event-driven architecture, payment gateways, ISO 8583, webhooks, HashiCorp Vault, distributed systems, system design, Resilience4j, mutual TLS, SAST remediation.

## Optional

- Full machine-readable profile: /llms-full.txt
- Sitemap: /sitemap.xml