ssemugenyiisaac2@gmail.com+256 705 438 524
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Isaac Ssemugenyi, Frontend Engineer

Available for work

I build interfaces that stay fast when the product gets complicated.

I'm Isaac, a frontend engineer with 4+ years in React and TypeScript. I've shipped payments flows, operational dashboards and booking platforms, and I care most about the parts users feel: loading, errors, and whether the screen can be trusted.

View the workRésumé
  • 4+years shipping frontend
  • 10products shipped
  • 6industries
  • TStyped end to end

Day to day

Selected work

Products I've helped ship

4+ years across fintech, marketplace and SaaS products. Each case study covers what the problem was, what I built and what I'd do differently.

  • mookh.com
    The Mookh homepage, showing event discovery search and category filters.
    Marketplace

    Mookh

    Creator commerce and event ticketing platform serving organisers across East Africa.

    Client
    Mookh
    • Next.js
    • React
    • TypeScript
    • Tailwind CSS
    • +1 more
  • jebapesa.com
    The Jeba Pesa homepage, introducing the cooperative fintech platform.
    Fintech

    Jeba Pesa

    Consumer fintech interface for payments and transfers, built with React and CSS Modules against a Redux Toolkit Query data layer.

    Client
    Jeba Jeba Limited
    Team size
    Team of 3
    • React
    • JavaScript
    • Redux
    • Redux Toolkit Query
    • +1 more
  • davsafaris
    The Dav Safaris fleet operations sign-in screen, split between branding and the login form.
    Logistics

    Davsafaris Fleet Management System

    Operations system that pulls vehicle tracking, driver and booking assignment, inspections, maintenance and client messaging into one place.

    Client
    Davsafaris
    • React
    • JavaScript
    • Axios
    • CSS Modules
    • +1 more
See All work

Capabilities

What I'm good at

These are the areas I've done real, reviewed work in.

  • Core

    The stack I reach for by default and have shipped production work in every year of my career.

    • React
    • TypeScript
    • JavaScript (ES2023)
    • Redux Toolkit
    • RTK Query
    • React Router
    • TanStack Query
    • TanStack Router
    • TanStack Start
    • TanStack Table
    • TanStack Form

  • Interface & styling

    Turning design files into interfaces that hold up across breakpoints, themes and input methods.

    • Tailwind CSS
    • CSS Modules
    • Styled Components
    • SASS
    • Design systems
    • Responsive layout
    • WCAG 2.2 AA

  • Performance

    Making pages fast on the devices and networks the audience actually has.

    • Core Web Vitals
    • Code splitting
    • Render optimisation
    • Bundle analysis
    • Image and font strategy
    • Caching

  • Testing & quality

    Writing the failing test first, so the design of the code answers to how it gets used.

    • Test-driven development
    • Vitest & Jest
    • React Testing Library
    • Integration testing
    • End-to-end testing
    • Mocking & test doubles
    • Coverage as a signal, not a target

  • Analytics & SEO setup

    Wiring measurement and the search essentials into a build. Integration and setup rather than campaigns or content strategy.

    • Google Analytics 4
    • Google Tag Manager
    • Google Search Console
    • Event & conversion tracking
    • Meta & canonical tags
    • Structured data (JSON-LD)
    • Open Graph & social cards
    • Sitemaps & robots.txt

  • Engineering practice

    How the work gets from a branch to live.

    • Git & GitHub
    • GitHub Actions
    • CI/CD pipelines
    • Agile delivery
    • Cross-browser debugging

  • Technical leadership

    What I take responsibility for beyond my own tickets.

    • Code review
    • Mentoring & onboarding
    • Technical decisions
    • Scoping & estimation
    • Setting conventions
    • Documentation & handover

Experience

Where I've worked

7 roles so far, each one closer to owning the interface end to end.

  1. Frontend Lead

    Current

    MookhRemoteRemoteFull-time

    Jan 2026 — Present

    • Lead frontend direction across the platform, setting the standards the rest of the work is reviewed against.
    • Own architecture decisions on state, component boundaries and performance budgets.
    • Review code and mentor engineers, focusing on the reasoning behind a change rather than only its output.
    • Next.js
    • React
    • TypeScript
    • Tailwind CSS
    • CI/CD pipelines

  2. Frontend Engineer

    MookhRemoteRemoteFull-time

    Sep 2024 — Dec 2025

    • Improve app speed and efficiency by optimising component rendering across the product surface.
    • Refactor existing code for readability and performance, splitting oversized components into composable units.
    • Identify and fix defects reported by users or caught during testing, tracing each to root cause.
    • Next.js
    • React
    • Tailwind CSS
    • Git workflows
    • CI/CD

  3. Frontend Engineer

    Jeba Jeba LimitedKampala, UgandaOn-siteContract

    Aug 2023 — Sep 2024

    • Implemented Figma designs in React at high fidelity for Jeba Pesa, a consumer fintech product.
    • Integrated API endpoints and handled data flows through Redux Toolkit Query, giving every screen consistent caching and error handling.
    • Optimised application performance and built responsive layouts with mobile treated as the primary case.
    • React
    • Redux
    • Redux Toolkit
    • JavaScript
    • CSS3
Full résumé

Also

I build WordPress sites too.

Custom child themes, Elementor Pro and WooCommerce for tour operators, law firms and non-profits. 7+ sites live, each one handed over to a client who runs it without me.

See the WordPress workStart a WordPress project

Available for work

Have something worth building?

I'm open to frontend roles and freelance work. Tell me what you're working on and I'll tell you honestly whether I'm the right fit.

Start a projectDownload résumé