Software Engineer & Systems Architect focused on payment systems, ISP infrastructure, and enterprise SaaS platforms. Experienced in building high-volume, production-grade systems in fintech and telecom environments.

Founder & Senior Software Engineer building fintech, ISP billing, and enterprise automation systems for African markets. Specializing in scalable APIs, payment reconciliation, and distributed system design.

Enterprise-grade payment engine — event-driven architecture, async queue processing, and automated reconciliation for high-volume African fintech systems.

Stack: Laravel · PHP · Redis · MySQL · M-Pesa Daraja API · Laravel Horizon

• Payment API Layer Handles STK Push, C2B, B2C, STK Query, and balance inquiry operations through Safaricom Daraja API with real-time status tracking.

• Webhook Ingestion Layer Secure, idempotent webhook handlers with signature validation and Redis-based deduplication to guarantee exactly-once processing.

• Queue Processing System Redis-backed async worker pool processes all payment events outside request cycle with retry logic and dead-letter queue handling.

• Transaction Ledger Immutable financial record system with audit-grade logs and double-entry-compatible transaction structure.

• Reconciliation Engine Nightly automated matching of Safaricom statements against internal ledger with anomaly detection and dispute flagging.

• 💳 10,000+ transactions processed monthly
• ⏱ Reconciliation time reduced: 4 hours → 15 minutes
• 💰 $500K+ monthly transaction volume processed
• 🤖 Fully automated dispute resolution pipeline
• 🔁 Zero duplicate transaction incidents in production

• Built exactly-once payment processing system using Redis locks + idempotent webhooks
• Designed event-driven architecture separating API layer from payment processing logic
• Implemented fault-tolerant queue system with retry, backoff, and dead-letter handling
• Automated reconciliation pipeline eliminating manual financial verification work
• Achieved production-grade fintech reliability under real transaction load

End-to-end ISP operations platform — subscriber lifecycle management, real-time bandwidth control via MikroTik RouterOS API, RADIUS authentication, and M-Pesa-driven automated billing.

Stack: PHP · MikroTik RouterOS API · React · TypeScript · FreeRADIUS · MySQL · SMS Gateway

• RouterOS API Integration Enables real-time bandwidth throttling, PPPoE session management, and hotspot user provisioning from a single unified admin interface.

• FreeRADIUS Authentication Layer Handles subscriber authentication and accounting with custom attribute mapping per package tier, ensuring accurate session tracking and policy enforcement.

• Billing Engine Supports dynamic package pricing, prorated renewals, and automated suspension/reactivation triggered instantly via M-Pesa payment callbacks.

• Multi-Tenant Architecture ISP-level isolation with per-tenant router configuration separation and subscriber namespace isolation to ensure data security and scalability across multiple providers.

• 👥 5,000+ active subscribers managed across 3 ISPs
• 🎯 99.8% billing accuracy achieved
• 🤖 100% automation of suspension and reactivation workflows
• 📡 3 ISP providers running on a single platform (multi-tenant system)
• ⚡ Real-time bandwidth policy enforcement via RouterOS API

• Eliminated manual ISP suspension processes through event-driven billing automation
• Reduced billing inconsistencies to near-zero using reconciliation logic tied to M-Pesa callbacks
• Improved operational scalability by introducing tenant-isolated ISP environments
• Enabled real-time network control directly from web-based admin dashboards

Multi-tenant SaaS business management platform — double-entry accounting, FIFO inventory costing, CRM, and automated invoicing serving 50+ SME clients across Kenya.

Stack: Laravel · React · TypeScript · MySQL · Redis · SendGrid · M-Pesa Daraja API

• Multi-Tenant SaaS Layer Schema-level isolation with domain-based tenant resolution ensuring complete data separation per client while maintaining a shared application core.

• Accounting Engine Fully automated double-entry system generating balanced journal entries for every financial transaction, with support for financial statements (P&L, Balance Sheet, Cash Flow).

• Inventory System FIFO costing engine with automated COGS journal entries, stock tracking, reorder alerts, and multi-warehouse transfer workflows.

• CRM Module End-to-end lead management system — leads → opportunities → quotes → invoices → payments with full activity tracking and pipeline visibility.

• Invoicing & Payment Pipeline Automated invoice generation, branded PDF templates, multi-channel delivery (Email + WhatsApp), and real-time reconciliation via M-Pesa callbacks.

• RBAC & Audit System Role-based access control with granular permissions across all modules and full audit trail tracking for every data operation.

• 🏢 50+ SME clients actively using the platform
• 📈 70% improvement in reporting efficiency
• 🔒 Zero cross-tenant data leakage incidents (3+ years)
• 🤖 100% automation of invoicing workflows
• 📦 Fully automated FIFO inventory costing and journal posting

• Eliminated manual accounting and invoicing operations through full automation
• Implemented scalable multi-tenant architecture supporting multiple businesses on a single system
• Reduced financial reporting time significantly through automated statement generation
• Improved operational accuracy via real-time reconciliation with M-Pesa payment flows
• Designed system for future microservice extraction with clean domain boundaries

Multi-channel communication platform — intelligent routing across WhatsApp Business Cloud API, Twilio SMS, and SendGrid Email with NLP chatbot, campaign automation, and analytics tracking.

Stack: Node.js · TypeScript · Redis · MySQL · WhatsApp Business Cloud API · Twilio · SendGrid

• Inbound Message Router Normalizes incoming messages from WhatsApp Webhooks, Twilio SMS, and SendGrid inbound email into a unified event format for processing.

• NLP Chatbot Engine Handles intent classification, entity extraction, and conversation state management with configurable confidence-based escalation to live agents.

• Outbound Routing Layer Smart channel selection with fallback logic: WhatsApp → SMS → Email based on delivery success and contact preferences.

• Campaign Scheduler Queue-based campaign execution with rate limiting, audience segmentation, and controlled delivery windows to comply with platform API limits.

• Analytics Engine Tracks delivery status, engagement metrics, and chatbot resolution performance across all communication channels.

• 📱 100,000+ automated interactions per month
• 💰 60% reduction in support operational costs
• 🤖 40% of tier-1 queries fully automated
• 📊 Unified communication across WhatsApp, SMS, and Email
• ⚡ Real-time escalation to human agents based on NLP confidence scoring

• Built a unified multi-channel messaging abstraction layer across 3 external APIs
• Implemented queue-driven rate limiting system to prevent API throttling
• Designed NLP-based intent routing system for automated customer support
• Reduced human intervention through automated resolution workflows
• Created scalable campaign system capable of handling high-volume messaging safely

Fintech & Payments Deep hands-on expertise with the M-Pesa Daraja API suite — C2B, B2C, STK Push, STK Query, and balance inquiry endpoints. Payment reconciliation pipelines, fraud detection hooks, and PCI-DSS compliant audit logging.

ISP & Network Automation MikroTik RouterOS API integration for PPPoE/hotspot management, FreeRADIUS for RADIUS authentication and accounting, automated bandwidth policies, and subscriber lifecycle management from sign-up to suspension.

Enterprise Architecture Multi-tenant SaaS system design with schema-level isolation, row-level RBAC, event-driven processing via queues, and clean domain boundaries for long-term maintainability. ERP, CRM, and billing modules built for scale.

Workflow Automation End-to-end automation across WhatsApp Business Cloud API, Twilio SMS, and SendGrid Email — unified routing layers, campaign schedulers, chatbot NLP, and analytics pipelines.

Technical Leadership Led distributed engineering teams across EMEA and EAT time zones. Full SDLC ownership from requirements, architecture design, and sprint planning through production deployment and incident response.

Note on contribution counts: Approximately 60% of my active development work lives in private client repositories — enterprise systems under NDA, proprietary fintech integrations, and ISP platform work. Public contributions represent the remaining ~40%.

What the patterns mean:

• Activity spikes — project launches, major feature releases, and intensive delivery phases
• Consistent baseline — ongoing maintenance, bug fixes, and incremental client improvements
• Lower periods — focus on private client deliverables, system architecture planning, and consulting engagements

✅ Senior / Lead Software Engineer roles at fintech or infrastructure-focused companies
✅ Technical Architect positions for payment systems and enterprise integrations
✅ Strategic consulting for ISP automation, billing platforms, and M-Pesa integrations
✅ Long-term partnerships with companies building products for African markets
✅ Open-source collaboration on payment infrastructure and developer tooling

• Remote-first, async culture with strong engineering ownership
• Fintech, SaaS, or ISP verticals — preferably serving emerging markets
• Teams that care about system correctness, not just shipping speed
• EMEA / EAT-compatible working hours

❌ Engagements under 3 months
❌ Equity-only arrangements
❌ Roles requiring full-time on-site presence

• Exploring: AWS infrastructure, microservices patterns, and blockchain payment rails for African markets
• Current focus: Scaling fintech systems beyond Kenya — cross-border M-Pesa, mobile money interoperability
• Contributing to: Open-source Laravel packages, React component libraries, and developer tooling
• Sharing knowledge: Technical tutorials on YouTube @zirohmae, mentoring junior developers

🏢 Brand: Ezems Tech Developers
🌐 Website: ezems.co.ke
📧 Email: ezems.developers@gmail.com
📞 Phone / WhatsApp: +254 101 086 123
📍 Location: Mombasa, Kenya 🇰🇪 — open to remote
💼 Status: Available for senior/lead roles and strategic consulting

"I don't just write code — I build systems businesses depend on. From MikroTik API to M-Pesa reconciliation engine, I architect solutions that handle real load, generate real revenue, and run reliably in production."

_{⭐ If any of my projects are useful to you, a star goes a long way · 🤝 Always open to interesting engineering conversations and collaboration}