Edwin Beshel Ayabie

Yumbarn is Tiango Logistics' food ordering and delivery platform connecting customers, vendors, and riders. As lead backend engineer I architected and deployed the core REST API serving all three client apps, built real-time order-fulfillment workflows including geolocation-based rider assignment and payment processing, and designed high-availability database schemas to keep order and payment state consistent under concurrent load. Introduced a Redis caching layer on hot read paths that cut API latency by more than 25% while the platform was handling 10,000+ orders a day.

• Core order API

  REST API serving the customer, vendor, and rider apps: catalog, ordering, and order-state transitions.

• Rider assignment & fulfillment

  Real-time, geolocation-based rider matching and order-fulfillment tracking from placement to delivery.

• Payment processing

  Secure payment capture and confirmation wired into the order lifecycle.

• Redis caching layer

  Caching on hot read paths cut API latency by 25%+ at 10,000+ orders/day without a database upgrade.

NectaBills is Techmakeeasy's fintech app for bill payments, airtime and data top-up, airtime-to-cash conversion, eSIM management, transfers, and interest-earning savings. I implemented the core billing and transaction workflows with idempotent processing to prevent duplicate charges across 100,000+ transactions a month, built asynchronous background pipelines on Celery and RabbitMQ for payment execution, retries, and reconciliation, integrated multiple third-party payment providers and VAS aggregators over REST and SOAP, and optimized database queries and task throughput for reliability under concurrent transaction load.

• Idempotent billing engine

  Transaction workflows built to reject duplicate charges by construction, holding up across 100,000+ transactions a month.

• Async payment pipeline

  Celery + RabbitMQ workers handling payment execution, retries, and reconciliation off the request path.

• VAS & provider integrations

  Multiple third-party payment providers and VAS aggregators integrated over REST and SOAP for airtime, data, eSIMs, and bill payments.

NectaSwap is Techmakeeasy's crypto companion app: swap crypto for Naira, plus NectaSwap Cards for spending globally and virtually. I built the crypto buy/sell flows and real-time authorization for the virtual cards, layered onto the same wallet and transaction infrastructure as NectaBills, reusing the same idempotent transaction processing and reconciliation pipeline.

• Crypto-to-Naira swap

  Crypto buy/sell flows layered onto the same wallet and transaction infrastructure as NectaBills.

• Real-time card authorization

  NGN/USD virtual cards with live balance control: POS/ATM transaction requests are routed to the backend for real-time approval or decline against the card's available balance.

Moodcraft is Ashinity Synergy's AI mental-health companion app: mood and emotion logging, trigger tracking, guided journaling, and creative tools (poetry, drawing, music) for emotional processing. I engineered and maintained a Retrieval-Augmented Generation pipeline for personalized, context-aware support, integrated and tuned LLMs for mood classification and response generation, built secure data-ingestion pipelines for sensitive user data, and developed the FastAPI services handling inference requests and continuous data capture. Shipped alongside a reported 40% lift in user engagement.

• RAG pipeline

  Retrieval-augmented generation for personalized, context-aware emotional-support responses.

• Mood classification

  LLM integration for classifying user mood/emotion from journaling and check-in input.

• Secure data ingestion

  Ingestion and processing pipelines built for sensitive user data with privacy in mind.

• Inference API

  FastAPI services handling live inference requests and continuous data capture from the app.

Zeelpay is a hybrid Web2/Web3 consumer fintech app: bill payments, airtime/data top-up, airtime-to-cash conversion, gift-card trading, Bitcoin/USDT trading, and NGN/USD virtual cards, alongside P2P transfers. I designed backend services supporting both the cryptocurrency and bills-payment sides of the product and enforced code quality through automated testing and review practices.

• Bills & VAS services

  Bill payments, airtime/data top-up, and airtime-to-cash conversion backed by aggregator integrations.

• Crypto trading & virtual cards

  Bitcoin/USDT trading and gift-card trading alongside NGN/USD virtual card issuance on shared wallet infrastructure.

• Real-time card authorization

  NGN/USD cards with live balance control: POS/ATM transaction requests are routed to the backend for real-time approval or decline against the card's available balance.

Shazzy is Shazz Tech's crypto wallet app: buy and sell tokens like BTC in your local currency, then spend directly using a Shazzy card in stores and online. I built the crypto wallet and card functionality, including real-time card authorization, and improved database performance through query optimization.

• Crypto wallet

  Buy/sell flows for tokens like BTC in the user's local currency.

• Card spending

  Card issuance with real-time authorization: transaction requests are routed to the backend for real-time approval or decline against the card's live balance.

Gexipay is a consumer fintech app for paying Nigerian bills, transferring money to bank accounts, converting airtime to cash, trading crypto and gift cards, issuing virtual cards, and funding betting wallets. I built the full backend: secure and compliant transaction-processing workflows, database performance work through indexing and query refactoring, third-party integrations over JSON and XML APIs, and real-time authorization for the virtual cards.

• Real-time card authorization

  Virtual cards with live balance control: POS/ATM transaction requests are routed to the backend for real-time approval or decline against the card's available balance.

Paysefy is Sefy Technologies' fintech bills-payment platform. I built the backend end-to-end: architecture, implementation, and technical documentation covering system design and backend standards, working closely with the frontend team on API integration.

• Backend architecture & implementation

  Owned the platform end-to-end, from architecture decisions through implementation.

• Technical documentation

  Authored system design and backend-standards documentation for the platform.

• Frontend integration

  Worked closely with the frontend team on API contracts and integration.

Tobopay is a Nigerian payments app: a wallet backed by a proper ledger, bill payments, airtime-to-cash conversion, and Tcash, a voucher-style cash-equivalent product. I built it end-to-end and solo, with nothing handed to me to maintain: wallet and ledger logic, bills and airtime-to-cash flows, Tcash vouchers, and NGN/USD virtual cards with real-time authorization — POS and ATM transaction requests routed to the backend for approval against the card's live balance — plus the infrastructure and deployment pipeline underneath all of it.

• Wallet & ledger

  Core wallet balance and ledger system tracking every user's money movement.

• Bills & airtime-to-cash

  Bill payments and airtime-to-cash conversion on top of the wallet.

• Tcash vouchers

  Voucher-style cash-equivalent product built on the wallet and ledger.

• Real-time card authorization

  NGN/USD virtual cards with live balance control: POS/ATM transaction requests are routed to the backend for real-time approval or decline against the card's available balance.

• Infrastructure & deployments

  Owned the deployment pipeline and backend infrastructure end-to-end, solo.

Waitstream replaces the walk-in clipboard with a live digital waitlist for service businesses: customers join a queue or book a slot, get automated status updates as their turn approaches, and the business gets AI-assisted signal on who's likely to no-show so they can overbook safely instead of losing revenue to empty slots. I designed, built, and deployed the entire backend solo: the waitlist and booking engine, the customer notification pipeline, and the no-show prediction logic underneath it.

• Waitlist & booking core

  Real-time queue and booking engine tracking each customer's position and slot end-to-end.

• Customer notifications

  Automated status updates keeping customers informed as their turn approaches, cutting drop-off.

• No-show prediction

  AI-assisted scoring that flags likely no-shows so businesses can overbook safely instead of losing revenue to empty slots.

• Solo backend ownership

  Entire backend designed, built, and deployed independently as the sole engineer.

Gxpanse merges a social feed with large-scale online shopping into one product: people browse and buy the way they'd scroll a timeline, with commerce and social sharing the same backend instead of being bolted together as separate apps. As freelance backend engineer I'm building the core services behind both sides: the social layer (profiles, feed, posts, engagement) and the marketplace layer (product catalog and the transaction flow behind it), on shared infrastructure.

• Social feed & profiles

  User profiles, posts, feed, and engagement (likes, comments, follows).

• Marketplace & catalog

  Product listings and the marketplace transaction flow behind them.

• Unified backend

  Social and commerce sharing one backend rather than two bolted-together systems.