Nelson OladejiNelson Oladeji
Let's talk
Available for select engagements · 2026

Engineering the infrastructure behind ambitious businesses.

I'm Nelson — CEO of Cognova Solutions Inc. and a Network / IT Systems & Solutions Engineer. I design resilient, scalable environments that stay online, stay secure, and use AI to move faster than the org they support.

Online
Remote / EMEA

Building for enterprises worldwide. Working hours align with your team.

99.98%

Avg. uptime shipped

40+

Deployments delivered

Secure Network Engineering

Design and hardening of routed, switched, and wireless networks — from campus to multi-site cloud interconnect.

CiscoFortiGateSD-WANVLANs

Foundational Cybersecurity

Defense-in-depth: firewall policy, endpoint hardening, IAM, and monitoring — protecting the assets that matter.

Zero TrustSIEMEDRMFA

AI-Powered Automation

Integrating LLM workflows and automation to remove toil from IT operations and unlock team velocity.

LLM Opsn8nPythonAPIs
About

I Build Software with AI, Not Just Using AI

Most developers use AI to generate code. I use AI to build systems.

My workflow focuses on architecture, context engineering, iterative implementation, evaluation, and refinement. Instead of manually writing every feature, I define constraints, provide domain knowledge, validate outputs, and continuously improve reusable development patterns that accelerate future work.

This approach has enabled me to build enterprise-grade platforms such as Haven Estate, Koventra, and Medova — production-oriented SaaS applications featuring multi-tenant architectures, financial workflows, visitor management, realtime communication, and compliance-focused operational systems.

I enjoy solving system-level problems, building scalable products, and using AI to increase engineering leverage without sacrificing software quality.

Toolbelt
Next.js
Node.js
React
TypeScript
Tailwind CSS
FastAPI
Python
SQLAlchemy
SQL / Postgres
Skills
React NativeExpoTypeScriptSupabasePostgreSQLMulti-Tenant SaaSRow Level SecurityPayment IntegrationPaystackRealtime SystemsEdge FunctionsDatabase DesignRole-Based Access ControlBackground JobsMobile Development
Contact

Have infrastructure that needs to evolve?

Whether it's a network refresh, a security posture review, or an AI automation pilot — let's scope it.

Elsewhere
Web applications I built

Shipped, in production. Real systems, real users.

Case study · Security & access management

Koventra — Enterprise Visitor and Access Management Platform

Live at NITDA HQ, Abuja · Built by Cognova Solutions Inc.

The problem

Many organizations still rely on paper visitor registers, phone calls, spreadsheets and manual approval processes to manage visitors and facility access. These processes create slow registration, limited visibility, difficult verification, poor audit trails, inefficient deliveries, limited emergency accountability and compliance risks.

  • Slow visitor registration and long wait times
  • Limited visibility into who is inside a facility
  • Difficult visitor verification
  • Poor audit trails
  • Inefficient package and delivery management
  • Limited emergency accountability
  • Compliance and privacy risks
  • Manual reporting and record keeping

The solution

I designed and developed Koventra as an enterprise-grade visitor and access management platform that connects administrators, security personnel and employees through one centralized system. It digitizes the complete visitor lifecycle — from invitation to exit — while giving security teams real-time visibility, operational controls and compliance-ready audit records.

My contributions

  • Designed the complete multi-tenant architecture
  • Developed role-based workspaces for administrators, security personnel and staff
  • Built OTP-based visitor verification workflows
  • Implemented visitor lifecycle management
  • Developed walk-in approval workflows
  • Built recurring visitor scheduling
  • Created emergency evacuation and roll-call functionality
  • Developed delivery and mailroom management
  • Implemented NDPA-compliant audit logging
  • Added configurable visitor workflows
  • Integrated WhatsApp OTP delivery
  • Implemented installable Progressive Web App functionality
  • Built offline check-in synchronization
  • Developed analytics dashboards
  • Implemented organization branding and customization

Technology stack

Next.js App RouterReactTypeScriptTailwind CSSPrisma ORMPostgreSQLJWT AuthenticationbcryptDocker ComposeResend EmailMeta WhatsApp Cloud APITwilio WhatsAppProgressive Web App
Visitor management
  • Visitor pre-registration
  • Secure one-time OTP generation
  • Visitor scheduling and rescheduling
  • Check-in and check-out management
  • Visitor history
  • Visitor types and workflows
  • Host assignment
  • Company and purpose tracking
  • Optional ID reference
  • Signed policy and NDA recording
Security operations
  • Dedicated security workspace
  • High-volume security queue
  • OTP verification
  • Camera-based visitor photo capture
  • Visitor asset recording
  • Badge management
  • Blacklist enforcement
  • Security kiosk mode
  • Gate activity monitoring
Walk-in & recurring visitors
  • Walk-in registration with host approval workflow
  • OTP generation after approval
  • Security-supervised registration
  • Vendor, contractor and consultant scheduling
  • Daily, weekly and monthly recurrence
  • Automatic visitor generation
  • Schedule pause and resume
Emergency & delivery
  • Emergency roll call and occupancy tracking
  • Muster point configuration
  • Missing-person reporting and evacuation accountability
  • Package logging and mailroom management
  • Recipient assignment and delivery notifications
  • Pickup tracking and delivery lifecycle management
Administration
  • User management and bulk user import
  • Company branding and location management
  • Visitor type configuration
  • Workflow customization and emergency settings
Analytics, compliance & PWA
  • Visitor, occupancy, delivery and blacklist analytics
  • Incident reporting and NDPA-ready audit exports
  • Audit logging, data retention and automatic anonymization
  • Installable PWA with offline verification and background sync
  • Browser notifications and service worker support
Security access control — queue, gate activity & blocklist
Admin console — user creation, bulk upload & client branding
Analytics — visitors by status, location, type & top hosts
Staff dashboard — invites, walk-in approvals & visitor history
Deliveries & mailroom — courier logging with offline cache
Emergency roll call — muster point accountability
Live arrivals dashboard — approval statuses & check-ins
Admin console — analytics cards & system user management
Host approvals — visitor status notifications
Invite a visitor — form and badge preview
OTP verification — secure check-in modal
Walk-in desk — unscheduled visitor registration

Technical architecture

Koventra follows a multi-tenant architecture where each organization operates in complete isolation while sharing the same backend infrastructure. Every tenant has independent users, visitors, facilities, branding, visitor types, operational workflows, audit records and analytics. Authentication uses JWT-based sessions while authorization is enforced through role-based access controls. The application is designed for high-volume security environments with offline capabilities for uninterrupted gate operations.

Technical challenges

Multi-tenant isolation

The application supports multiple organizations from one deployment while ensuring complete separation of operational data, branding and workflows.

High-volume security operations

The security workspace was designed to minimize visitor processing time through optimized queues, OTP verification and streamlined check-in workflows.

Offline gate operations

Security personnel can continue verifying approved visitors even without internet connectivity. Offline events are queued locally and synchronized automatically when connectivity returns.

Flexible visitor workflows

Organizations often require different visitor policies. Koventra allows administrators to configure visitor types that require photographs, ID references, approvals, asset capture, signed acknowledgements and badge issuance without changing application code.

Compliance

The platform includes configurable data-retention policies, anonymization workflows and audit logging to support privacy and regulatory requirements.

Current status

Koventra is production-oriented and suitable for demonstrations, pilot deployments and controlled staging environments. Optional integrations such as WhatsApp messaging and email notifications can be enabled through provider configuration depending on customer requirements.

What I learned

Enterprise application architectureMulti-tenant SaaS developmentVisitor lifecycle managementRole-based access controlProgressive Web ApplicationsOffline-first application designAuthentication and authorizationSecurity workflow designAudit loggingCompliance-aware software developmentWorkflow automationEnterprise dashboard development
Case study · Multi-tenant SaaS

Haven Estate — Multi-Tenant Estate Management & Access Control Platform

Staging / portfolio demonstration · Three apps, one shared backend

Haven Estate replaces the spreadsheets, WhatsApp groups, bank statements and paper visitor registers that residential estates run on with one secure digital system. It ships as three independent applications — Haven Estate Manager for owners, managers and accountants, Haven Resident for residents and tenants, and Haven Security for gate personnel — all connected to a shared Supabase / PostgreSQL backend with database-level tenant isolation, role-based permissions and Row Level Security.

My contributions

  • Designed the multi-tenant system architecture and estate-level data isolation
  • Structured the platform as three independently deployable applications
  • Implemented billing, recurring payments and Paystack init / verify / webhooks
  • Designed a ledger-based resident wallet and concurrency-safe payment flows
  • Built visitor invitation and realtime gate-verification processes
  • Designed accounting, settlement and maker-checker approval controls
  • Implemented background jobs for recurring billing and message delivery
  • Prepared the apps for Android, iOS and web deployment (EAS Build / Update)
React 19React Native 0.86Expo SDK 57TypeScriptReact Native WebSupabasePostgreSQL 17Row Level SecurityRealtimeStorageEdge FunctionsPaystackResendTermiiExpo PushZodEASpnpm
Estate Manager — community operations, collections & occupancy
Resident app — account overview, bills, wallet & issues
Security console — realtime gate verification & access events
Visitor invitations — one-time passwords verified at the gate
Workspace modules — people, billing, accounting, reports & more
Haven wallet — secure top-ups and instant estate bill payments
Issue desk — categorised reports with conversation threads
Estate management
  • Estate & housing-unit management with occupancy analytics
  • Resident occupancy, unit assignment and role-based staff administration
  • Maintenance, asset and security workspaces
  • Resident issue management, amenities and reservations
Billing & payments
  • Bill types, tariffs and recurring billing for one, some or all units
  • Paystack online payments, wallet top-ups and wallet-based bill payments
  • Payment history, receipt sharing and overdue tracking
  • Revenue, collection and outstanding-balance analytics
Financial controls
  • Double-entry-style wallet ledger with server-controlled transactions
  • Idempotent webhook processing and settlement-account verification
  • Settlement batching with maker-checker approval
  • Accounting journals, chart of accounts and reconciliation exceptions
Visitor & security
  • Visitor invitations with one-time gate codes and OTP verification
  • Realtime expected-visitor register, check-in / check-out
  • Resident arrival notifications and immutable visit history
  • Patrol logs, gate events and security watchlists
Resident services
  • Secure registration, unit & profile information
  • Bills, statements, payment history and receipts
  • Issue reporting with image attachments and two-way conversations
  • Announcements, notification preferences, light & dark themes
Communication
  • Targeted and estate-wide announcements plus in-app notifications
  • Email via Resend, SMS via Termii, Expo push infrastructure
  • Retryable delivery with exponential backoff and failure recovery
  • Background processing driven by recipient preferences

Technical challenges

Multi-tenant data isolation

One backend serving many estates. Every operational record is tied to an estate, with membership and role checks enforced through PostgreSQL Row Level Security and server-side authorization functions — so requests made outside the app still can't cross tenants.

Reliable payment processing

Providers retry and duplicate webhooks. The payment workflow processes events idempotently so a single payment can never be applied twice.

Wallet accounting

Balances are derived from completed ledger postings rather than an editable field, and wallet bill payments create settlement obligations that a separate finance user must authorize.

Preventing booking conflicts

Amenity reservations use database-level exclusion constraints inside transactions, so two residents can't hold the same slot.