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My Portfolio
Chukwuemeka Favour Onyechere, Website & Mobile App Developer
About me

Seven years turning requirements into systems that stay up.

I am a full-stack engineer with seven years building production web and mobile applications, including two years delivering remotely for a UK product team at RUAC Tech.

My core is React, Next.js, and TypeScript on the front, with hands-on ownership of Node.js and Express services, REST and GraphQL API design, PostgreSQL and MongoDB modelling, and AWS deployment behind it.

Most of my work has been in financial and transaction-heavy products, the kind where a bad deploy costs real money. That shaped how I write code: typed, reviewed, monitored, and documented for whoever picks it up next.

Chukwuemeka Favour Onyechere

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Engagement lift
28%Engagement lift
Crash rate reduction
40%Crash rate reduction
Search latency reduction
60%Search latency reduction
Shipped products
20Shipped products
How I build

Three things I do not negotiate

  • Types are documentation

    Strict TypeScript across the boundary means the next engineer reads the contract instead of guessing it. Interfaces get written before implementations.

  • Ship it instrumented

    A feature is not done when it renders. Monitoring, error boundaries, and a measurable baseline go out in the same release, otherwise nobody knows when it breaks.

  • Accessible by construction

    Semantic markup and keyboard paths cost nothing when they go in first and cost a rewrite when they go in last. WCAG 2.1 is the floor, not the target.

The toolkit, and how deep it goes

  • Re95%

    React

  • Nx94%

    Next.js

  • Ts92%

    TypeScript

  • Nd88%

    Node.js

Frontend

  • React Native88%
  • Redux and Redux-Saga86%
  • Tailwind CSS92%
  • WCAG 2.1 accessibility85%
  • Responsive design94%

Backend

  • Express.js90%
  • REST API design92%
  • GraphQL78%
  • WebSockets80%
  • OAuth 2.0 and JWT87%
  • Microservices76%

Data

  • PostgreSQL86%
  • MongoDB89%
  • Schema design85%
  • Query optimisation80%
  • Elasticsearch72%

Cloud and DevOps

  • AWS EC2 and S382%
  • CI/CD pipelines84%
  • Automated testing80%
  • Git95%
  • Performance monitoring86%
Career

Where the experience came from

  1. Frontend Engineer (Full-Stack Contributions)

    Current

    RUAC Tech · United Kingdom (Remote)

    Feb 2024 – Present

    • Architected the component layer of a production React and TypeScript application with Tailwind CSS, standardising UI patterns across the product and driving a 28% increase in user engagement measured in product analytics
    • Shaped REST API contracts alongside the backend team, refining request and response payloads to cut redundant round-trips and simplify client-side state handling
    • Instrumented performance monitoring across key product pages, isolating render and payload bottlenecks and cutting average load times by 35%
    • Brought the product to WCAG 2.1 conformance through semantic markup, layout, and keyboard navigation
    • Operated as a fully remote engineer embedded in a UK product team, sustaining delivery through written handovers, documentation, and code review with product, QA, and backend
    • React
    • TypeScript
    • Tailwind CSS
    • REST APIs

  2. Software Engineer (Full-Stack and Mobile)

    Lexis Development Company · Lagos, Nigeria

    Aug 2022 – Jan 2024

    • Built a peer-to-peer cryptocurrency exchange end to end across a React Native client, Node.js services, and a Redux state layer, sustaining around 99.99% uptime while processing 500+ transactions daily
    • Owned authentication and payment integration paths (OAuth 2.0, JWT, Stripe, Paystack, Flutterwave), the most security-sensitive surface in a financial product
    • Designed and hardened backend transaction flows and third-party integrations, accelerating transaction processing by 30% and reducing the crash rate by 40%
    • Delivered ride-hailing features across both stacks, spanning real-time location tracking and GPS on the client and the supporting service and payment logic, increasing active users by 25%
    • React Native
    • Node.js
    • Redux
    • Stripe
    • Paystack
    • Flutterwave

  3. Full Stack Developer

    Mastagate · Kinshasa, DR Congo

    Nov 2020 – Jun 2022

    • Led end-to-end delivery of web and mobile products on React, React Native, Node.js, and MongoDB, owning the stack from data model through interface
    • Built and maintained RESTful APIs and microservices to decouple client and server concerns, improving response times by 35%
    • Introduced CI/CD pipelines and automated test coverage, streamlining release cycles and cutting production defects substantially
    • React
    • React Native
    • Node.js
    • MongoDB
    • CI/CD

  4. Frontend Developer

    Resos Consulting Tech Limited · Owerri, Nigeria

    Jul 2018 – Oct 2020

    • Engineered a shared component library with React and Next.js, cutting page load time by 30% and improving user satisfaction in post-release surveys
    • Integrated frontend features against backend and design deliverables to ship complete releases, reducing time-to-market
    • React
    • Next.js
    • JavaScript
Credentials

Certifications and education

  • May 2025

    AWS Certified Developer, Associate

    Amazon Web Services

    Certification
  • Jul 2024

    Frontend Developer Capstone

    Meta via Coursera

    Certification
  • Mar 2023

    Modern React with Redux

    Udemy

    Course
  • 2024

    BSc Biochemistry

    Gregory University Uturu, Nigeria

    Degree
Next step

Have something that needs building?

Websites, ecommerce stores and mobile apps for businesses and startups. Tell me what you are working on and I will come back within a day.

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