ABOUT ME

Senior Backend Engineer | Wallet, Payments & Billing

Building the backend systems that move real money: wallet infrastructure, payment processing, subscription billing, and the PostgreSQL work that keeps it reliable.

WALLET SYSTEMS PAYMENT INFRASTRUCTURE POSTGRESQL SPECIALIST TECHNICAL WRITER
PROFILE

Senior Backend Engineer specializing in Ruby on Rails, wallet systems, payment infrastructure, and billing platforms. Currently building wallet and payment processing systems in a fintech context. Previously owned the full money path: subscriptions, trials, add-ons, invoicing, bank-transfer rails, dunning, and churn recovery, plus the integrations that make it work (Chargebee, HubSpot, NetSuite, ZATCA, Segment). Rails core contributor (PR #51078).

  • Build wallet infrastructure and payment processing systems: payment order management, transfer synchronization, real-time reconciliation, and idempotency guards
  • Previously built the full billing stack: Chargebee subscription billing, Virtual IBAN bank transfers, failed-payment recovery (dunning), and churn-save funnels
  • PostgreSQL specialist: index optimization, query tuning, partial indexes for soft-deleted models, and cache invalidation strategies
  • Active Rails core contributor and technical writer sharing backend and payment engineering lessons
EXPERIENCE 8+ YEARS
Senior Software Engineer
JISR
  • Build wallet infrastructure and payment processing systems: payment order management, wallet inquiries, transfer synchronization, and real-time reconciliation
  • Own payment infrastructure: retry optimization with idempotency implementation, significantly reducing payment failures
  • Design webhook processing systems for payment providers and CRM integrations
  • Conduct code reviews and mentor engineers on payment system best practices
  • Drive PostgreSQL performance: audit and remove duplicate indexes, improving write performance
WALLETSRUBY ON RAILSPOSTGRESQL WEBHOOKSIDEMPOTENCYAWS
Software Engineer
JISR
  • Built configuration-driven trial management system for subscription billing
  • Designed and shipped the subscription cancellation and retention funnel end to end
  • Engineered bank-transfer payment rails with per-organization Virtual IBAN provisioning across two banking providers with idempotent issuance and graduated retry
  • Designed event-sourced subscription audit log with jsonb snapshots, partial composite indexes, and async SQS writes
  • Implemented dunning pipeline for failed-payment recovery with automated offline-billing fallback and full state-transition history
  • Integrated Chargebee subscription billing with webhook processing and automated seat-count reconciliation
  • Built bidirectional HubSpot CRM sync across trial and paid lifecycle with pre-flight validation
  • Implemented Segment analytics pipeline delivered over SQS with daily and weekly reconciliation syncs
  • Migrated reports from synchronous to async processing via AWS SQS, eliminating timeout errors
  • Built automated invoice generation with NetSuite and ZATCA e-invoicing compliance
RUBY ON RAILSCHARGEBEEAWS SQS SEGMENTHUBSPOTREDISRSPEC
Software Engineer
CLICKAPPS
  • Designed and built robust backend logic for web applications
  • Ensured high code quality through comprehensive testing and systematic version control
  • Contributed to API development and deployment automation processes
  • Enhanced application performance by optimizing database queries and job processing
RUBY ON RAILSPOSTGRESQLREDIS AWS EC2CAPISTRANO
OPEN SOURCE

Fixed where.associated join type override in Rails core.

A bug in ActiveRecord silently overrode existing join types in complex queries. The fix preserves what you wrote (INNER JOIN vs LEFT OUTER JOIN) based on existing scope joins.

  • Consistent SQL for complex association filtering
  • Preserves join types when using left_joins with where.associated
  • More predictable query behavior for every app on Rails
PR #51078 · MERGED FEB 2024
CORE SKILLS
Wallet, Payment & Billing
  • Wallet systems: balance operations, wallet inquiries, transfer sync
  • Payment processing: order management, real-time reconciliation
  • Fintech infrastructure: payment reliability patterns, idempotency guards
  • Chargebee: subscription billing, retry logic, webhook processing
  • Virtual IBAN: bank transfer payment rails
  • Reconciliation: automated matching of internal vs provider records
  • Webhook processing: signature verification, idempotent handlers
  • Dunning: failed payment recovery pipelines
  • HubSpot: bidirectional CRM sync
  • NetSuite / ZATCA: e-invoicing regulatory compliance
Languages & Frameworks
  • Ruby: advanced proficiency, 8+ years in production
  • Ruby on Rails: expert level, specializing in backend development
  • RESTful APIs: design and implementation of scalable APIs
  • MVC architecture: clean, maintainable application structure
Databases & Performance
  • PostgreSQL: advanced optimization and tuning
  • MySQL: production database management
  • Redis: caching and session management
  • Performance: query optimization and database tuning
Cloud & Infrastructure
  • AWS: EC2, S3, SQS, RDS deployment and management
  • CI/CD: pipeline setup and deployment automation
  • Docker: containerization and orchestration
Testing & Quality
  • RSpec: comprehensive test suite development
  • TDD: quality-first development approach
  • Code reviews: maintaining high code quality standards
Background Processing & Tools
  • Sidekiq / Resque: background job processing
  • Third-party APIs: integration and management
  • Git, GitHub, GitLab: version control and collaboration
  • Mentorship: code reviews, team collaboration, developer guidance
EDUCATION & LANGUAGES
DEGREE B.SC. INFORMATION TECHNOLOGY
UNIVERSITY ADEN UNIVERSITY · FACULTY OF ENGINEERING
ARABIC NATIVE
ENGLISH PROFESSIONAL WORKING PROFICIENCY