Skills & Technologies
23 skillsreactangularreact nativetypescriptjavascripthtml/csstailwind cssreduxzustandtanstack querynode.jsexpress.jspostgresqlprismaredisrest api designgitexposupabasecloudinaryk6figmaandroid studio
Work Experience
Angular Frontend Developer
Innovastra Inc
Oct 2023 - Present Lagos, Nigeria (Remote)
- Built a configuration-driven Angular module that centralized tab definitions, role visibility, filters, table schemas, and dialog controls, allowing new tabs to be added without component changes.
- Engineered a multi-select field system supporting three distinct option-resolution strategies (static config, dynamic GET, dynamic POST with custom payloads), with type-safe extension points via a MultiSelectFetchKey union type enforced at compile time
- Implemented role-based tab filtering evaluated at runtime against the authenticated user's role, ensuring downstream logic (pagination, dialogs, event handlers) always operates against the filtered tab set — not the raw config
- Optimized API performance by introducing request caching for frequently-accessed data, reducing redundant backend calls across high-traffic components
- Collaborated with backend team to improve API error contract handling and implement consistent loading states across multiple modules
- Implemented timezone-aware date and time rendering across scheduling modules, ensuring accurate appointment display for users across different timezones
- Restructured clinical workflow modules — including antenatal care and ANC visit categorization — to reflect real- world care pathways and reduce user navigation friction
- Extended filtering capabilities across multiple platform modules, including multi-user filter selection, filter grouping, and advanced search on revenue analytics
Frontend Developer (Part-time, Volunteer)
CredenceApp
Mar 2023 - Mar 2024 Lagos, Nigeria (remote)
- Built the web application MVP from scratch using React and Tailwind CSS during final year of university
- Delivered a complete MVP frontend covering dashboards, user management, and form workflows
- Built reusable component library maintaining consistency across the platform through the MVP build phase
Projects
Attendance System
ReactTypeScriptNode.jsExpressPostgreSQLPrismaRedis
- Built a full-stack attendance queue system handling geolocation-validated check-ins, session-based queue management, and designed for multi-LGA scale from the ground up
- Diagnosed connection pool exhaustion under load using k6 stress testing — at 600 VUs, throughput flatlined at 94 req/s while p95 latency hit 6s, a 3.5x degradation against 3x load growth. Fixed by caching session state in Redis, cutting redundant Postgres queries on data that changes twice per session at most
- Designed PostgreSQL schema with deliberate indexing strategy to support efficient lookups at scale across locations and sessions
- Resolved iOS cross-domain httpOnly cookie failure by implementing a Vercel reverse proxy to unify API and frontend origins
- Implemented geolocation validation using watchPosition with accuracy thresholds instead of getCurrentPosition, stopping the watch once coordinates meet the required precision
FC Pulse
React NativeExpoSupabasePush Notifications
- Built a cross-platform football notification app using React Native and Expo, integrating Football-Data.org for match data and Supabase for authentication, real-time sync, and Row Level Security.
- Engineered customizable push notifications, allowing users to set reminders from 15 minutes to 24 hours before kickoff for favorite and rival clubs.
- Implemented a subscription model where users follow leagues for daily schedules and receive personalized club alerts, with Zustand managing match and preference state.
BookReview
ReactTypeScriptNode.jsExpressPostgreSQLPrismaCloudinary
- Built a full-stack book review platform end-to-end, taking sole ownership of both frontend and backend — designed the REST API, modelled the database schema, and deployed independently to Vercel and Render
- Implemented JWT authentication with refresh token rotation, email verification via Nodemailer, and optional auth middleware to serve mixed public/private endpoints from a single route
- Engineered a review system maintaining denormalized avgRating and reviewCount columns, recalculated on every mutation to keep read queries fast without runtime aggregation
- Built infinite scroll pagination using TanStack Query’s useInfiniteQuery and IntersectionObserver, with debounced search and server-side sorting to avoid client-side pagination errors
- Integrated Cloudinary for book cover image uploads via Multer, with Neon (serverless PostgreSQL) as the database layer managed through Prisma ORM
Weather-Based Crop Yield Predictive System
PythonFlaskXGBoost
- Developed a machine-learning predictive system for cassava and cocoa yield using historical weather data from NASA POWER and agricultural data from Kaggle.
- Built backend logic in Python with XGBoost for modeling nonlinear relationships between weather patterns and crop yield.
- Deployed the prediction engine using a Flask API, serving model outputs to a lightweight web interface built with HTML/CSS (Tailwind CSS).
- Implemented automated weather data retrieval and integrated user inputs into a responsive UI for farmers to obtain yield forecasts.
Leaderboard Standings
Leaderboard Position Pending
Global test scores, peer standing percentiles, and algorithm leaderboard ranks are updated dynamically.
Assessment Highlights
Assessments Not Completed
Coding evaluations, system assessment results, and conceptual score badges will appear here after taking a test.
AI Collaboration Score
AI Collaboration Score Pending
Developer coding behavior, assistant cooperation, and AI pair-programming indicators are evaluated during live coding sessions.
Role Compatibility Profile
Role Compatibility Analysis Pending
Custom matching reports, candidate role compatibility percentiles, and core engineer strength profiles are processed once conceptual code screenings are complete.
Achievements
Achievements Not Earned
Special rewards, developer badges, system recognition certificates, and conceptual milestones will display here.
About Details
Professional Bio
Frontend-focused software engineer with 3+ years of production experience on a healthcare platform. Experienced in architecting configuration-driven UI systems, designing scalable Postgres schemas, and diagnosing backend system performance under real load.
B.Tech. in Information Technology in Information Technology
Federal University of Technology Akure, Nigeria ( - Present)
Languages: English, Hindi
Email: Locked
GitHub: https://github.com/harlloh