Rela Express
A multi-market logistics platform coordinating real-time delivery, courier verification, payments and operations across Nigeria and the United Kingdom.
Visit Rela Express (opens Rela Express website in a new tab)A system shaped by real-world constraints.
Rela Express coordinates delivery operations across Nigeria and the United Kingdom, bringing customers, couriers, dispatch, pricing, payments, communications and administration into a shared operational model.
Courier participation depends on a country-aware onboarding and identity workflow that combines evidence from external verification providers with an explicit administrative decision.
Where I contributed.
- Backend leadership and full-stack engineering across the core API, real-time delivery workflows, courier onboarding, identity integrations, administrative operations, payments and background workers.
- Owned boundaries connecting NestJS request handling, MongoDB transaction flows, Redis coordination, BullMQ workers and operational telemetry.
What made the work difficult.
- The United Kingdom and Nigeria require different identity, right-to-work and vehicle evidence, with further variation based on the courier's delivery vehicle.
- Provider results and submitted documents had to support human review without allowing automated evidence collection to become an approval decision.
- Courier matching and acceptance needed to remain correct under concurrent activity while payment, refund and notification work remained recoverable.
What mattered technically.
Country-aware verification
Resolved required onboarding steps from the courier's country and delivery vehicle. UK couriers use VouchSafe for right-to-work evidence and DVLA for licence and vehicle checks; Nigerian couriers use Interswitch for NIN verification and QoreID for licence and vehicle checks.
Human-in-the-loop approval
Kept provider evidence separate from approval. Each applicable step moves through pending, validated or invalidated states; invalidation carries a reason, resubmission reopens review, and final account approval is blocked until every required step is validated.
Durable evidence and audit
Stored submitted documents behind an AWS S3 boundary, validated object keys, recorded consent and wrote onboarding changes with before-and-after audit records inside the same MongoDB transaction.
Race-safe delivery
Combined geospatial courier matching, Redis-backed Socket.IO coordination and conditional MongoDB updates so only one courier can successfully claim an available delivery.
Recoverable financial workflows
Reconciled Stripe and Paystack events against internal transactions, used idempotent settlement keys and kept refund or compensating ledger work recoverable when delivery or provider workflows failed.
Dedicated background work
Moved email, WhatsApp, push, reminder and live-activity work into BullMQ workers with payload validation, Redis idempotency markers, retries, dead-letter queues and graceful shutdown.
Correctness beyond the happy path.
- Redis-backed sessions enforce one active session per account, with shorter idle and absolute limits for administrators and explicit revocation when access changes.
- Single-use OTP challenges are HMAC-digested, time-limited, attempt-limited and compared without timing leaks.
- Distributed rate limiting and permission-scoped administration protect verification and operational actions.
- New Relic telemetry uses sanitized request and worker payloads so credentials, tokens and document-like data are redacted or summarized before logging.
What the work made possible.
- Keeping country and vehicle policy explicit made verification requirements reviewable instead of scattering market rules across interfaces.
- Separating provider evidence from approval preserved a human decision point for incomplete, conflicting or exceptional records.
Technology should support the system, not become the story.
TypeScript · Node.js · NestJS · MongoDB · Redis · BullMQ · Socket.IO · AWS S3 · Stripe · Paystack · New Relic