Caleb is available for hire
Hire CalebCaleb Rotich
Verified Expert in Engineering
Software Developer
Location
Nairobi, Nairobi County, Kenya
Toptal Member Since
February 28, 2022
Caleb is a proficient software engineer with vast experience in web technologies, architecture, performance, and security. He has helped build and improve the quality of applications across education, eCommerce, and management sectors, collectively serving millions of active users. Caleb has a strong user focus and developed excellent communication skills in leading and working with small and large distributed teams.
Portfolio
SMSLeopard
JavaScript, Node.js, A/B Testing, Jest, Cypress, Unit Testing, Flow, i18n...
Marmalade Labs, Inc
React, Apollo, Next.js, TypeScript, Tailwind CSS, GraphQL...
Apaleo
React, Next.js, TypeScript, Tailwind CSS, Contentful, HTML, HTML5, Algorithms...
Experience
Availability
Full-time
Preferred Environment
MacOS, Linux, Slack, GitHub, Visual Studio Code (VS Code), Zoom, Firefox, Chrome, Google Hangouts, BlueJeans
The most amazing...
...project I've worked on is an eCommerce platform. The platform provides a great user experience and promotes an easy discovery of products and services.
Work Experience
Senior Full-stack Developer
2023 - 2024
SMSLeopard
- Integrated two-factor authentication with a security key to enhance the security and user experience of the web application.
- Implemented Sentry and Google Analytics to track and monitor JavaScript errors, performance issues, and user behavior on the web application.
- Developed and deployed bulk airtime and data purchase features, increasing customer satisfaction and revenue.
Technologies: JavaScript, Node.js, A/B Testing, Jest, Cypress, Unit Testing, Flow, i18n, Internationalization, Security, UI Testing, Sentry, Google Analytics, Google Analytics 4, Front-end Architecture, Front-end Design, Playwright, WCAG 2, APIs
Senior Front-end Developer
2022 - 2023
Marmalade Labs, Inc
- Migrated the application across a major version, Next.js 12 to Next.js 13.
- Improved the app performance via the Core Web Vitals by reducing the client-side JavaScript.
- Oversaw the launch of the three major application versions, which introduced critical user-facing features.
Technologies: React, Apollo, Next.js, TypeScript, Tailwind CSS, GraphQL, Server-side Rendering (SSR), Single Sign-on (SSO), Google Sign-in, Slack, JavaScript, Storybook, OpenAI, Web Usability, Search Engine Optimization (SEO), Vercel, Hygraph (GraphCMS), Google Analytics, UI Development, Monorepos, Axios, Front-end Architecture, Front-end Design, React Query, APIs
Senior Front-end Developer
2022 - 2022
Apaleo
- Migrated web applications from legacy WordPress applications to performant React single-page applications.
- Improved web vitals for the web applications, leading to highly optimized and performant applications.
- Helped rebrand web applications by transforming designs and wireframes into high-quality modular code.
Technologies: React, Next.js, TypeScript, Tailwind CSS, Contentful, HTML, HTML5, Algorithms, JSX, NPM, i18n, Localization, Amazon Web Services (AWS), Web Development, Content Management Systems (CMS), Responsive Web Apps, Serverless, Front-end, Scrum, Microservices, User Experience (UX), User Interface (UI), Test-driven Development (TDD), Bitbucket, Front-end Development, SaaS, Slack, JavaScript, Web Usability, Search Engine Optimization (SEO), UI Development, Axios, Front-end Architecture, Front-end Design, APIs
Senior Software Developer
2019 - 2022
Ideas Come To Life | ICTLife
- Developed an eCommerce application that facilitates easy trades between merchants and customers.
- Built and guided a team in developing a financial application that analyzes transactions and provides beautiful transactional statements. The application gained over 1,000 active users in one week.
- Created an in-house messaging application to be integrated into the other company's products. The application facilitates quick communication between users without the need for third-party integrations.
- Led front-end developer teams in ensuring efficient communication, collaboration, and quick delivery of tasks.
- Helped product owners and managers in continuous brainstorming of product implementation ideas.
- Updated and improved legacy applications to ensure optimal performance and security against common client-side attacks.
Technologies: JavaScript, React, Next.js, Node.js, Redux, Material UI, HTML, Sass, TypeScript, MacOS, Software Engineering, Data Structures, CSS, GitHub, HTML5, Algorithms, React Redux, Amazon Web Services (AWS), Web Development, Responsive Web Apps, OAuth, JSON Web Tokens (JWT), REST APIs, Front-end, Scrum, Microservices, User Experience (UX), User Interface (UI), Test-driven Development (TDD), React Router, Bitbucket, Front-end Development, SaaS, Server-side Rendering (SSR), Google Sign-in, Single Sign-on (SSO), Tailwind CSS, Slack, Material Design, Web Usability, Search Engine Optimization (SEO), WordPress, Vercel, Google Analytics, Google Cloud, Firebase, Docker, Stripe API, UI Development, Monorepos, Axios, Front-end Architecture, React Query, APIs
Front-end Developer
2019 - 2020
LifeStores Pharmacy
- Developed an app that manages the medical inventory of the pharmacy.
- Created a scalable and thoroughly tested app with front-end testing tools.
- Worked with the back-end team and designers to provide rich, user-driven interfaces.
Technologies: React, JavaScript, TypeScript, CSS, GraphQL, Redux, Material UI, HTML, Software Engineering, Data Structures, GitHub, Web Development, Front-end, Scrum, User Experience (UX), User Interface (UI), React Router, Bitbucket, Front-end Development, SaaS, Slack, UI Development, Axios
Software Engineer
2018 - 2019
Freelance
- Worked on in-house applications that streamlined the daily operations of the company.
- Built an education system that managed examination processing for schools.
- Guided junior developers and provided mentorship in their early developmental journey.
Technologies: Python, Django, React, HTML, Material UI, Redux, JavaScript, Software Engineering, Data Structures, CSS, GitHub, Front-end, REST APIs, Jira, Scrum, User Experience (UX), User Interface (UI), React Router, Bitbucket, Front-end Development, SaaS, Slack, PostgreSQL, Stripe, Search Engine Optimization (SEO), CI/CD Pipelines, UI Development, NestJS, Axios, React Query
Front-end Developer
2017 - 2018
Faiyol Systems Limited
- Developed an examination system application with C# and JavaScript.
- Wrote well-designed, testable, and efficient code using the best software development practices, raising the efficiency and speed of the company's application.
- Managed the complete development process of an application from inception to deployment.
Technologies: .NET Core, C#, JavaScript, HTML, Software Engineering, Data Structures, CSS, GitHub, Web Development, Front-end, User Experience (UX), User Interface (UI), Front-end Development, Slack, PostgreSQL, UI Development
Experience
Marketplace App
https://www.africasasa.comA JavaScript application that provides a smooth marketplace experience. The application helps users discover trusted local businesses to interact with and find services, food, activities to do, and places to stay closer to them.
AI-powered eCommerce Application
https://www.marmalade.coA React and Python-based application that lets users create a profile and then uses AI to show real makers, inventors, designers, artisans, and family-owned businesses who value what the user values.
Whether the user is all about sustainability, looking for products built to last, or wants to treat themselves to something special, the application is designed to help them explore products made by brands that care about their craft. The app is like a search engine laser-focused on small and independent brands online.
Whether the user is all about sustainability, looking for products built to last, or wants to treat themselves to something special, the application is designed to help them explore products made by brands that care about their craft. The app is like a search engine laser-focused on small and independent brands online.
Application Store
https://store.apaleo.com/A Next.js application that categorizes applications in a hospitality platform. I was in charge of building new interfaces and ensuring the application was highly performant. I optimized the application by ensuring the site was static through pre-generating pages from dynamic data.
Web App Migration and Rebranding
https://apaleo.com/A company website built with React and NextJS. This project featured a fully customizable website generated by a database and statically rendered with Next.js. I took part in planning and developing data models and components for the app.
eCommerce Application for Merchants
https://merchant.africasasa.comA React-based application that enables merchants to create business profiles and sell products in the marketplace.
I worked on the user interface and ensured a smooth user experience between different application sections. I got to work with modern web development tools like Next.js while ensuring high application performance.
I worked on the user interface and ensured a smooth user experience between different application sections. I got to work with modern web development tools like Next.js while ensuring high application performance.
School Examination Management System
https://github.com/calebrotich/ExaminationSystemA .NET Core-based application for processing examinations in local universities.
I worked on the JavaScript and CSS front end as well as the .NET back end. The application integrated third-party integrations to output rich results processed by the system.
I worked on the JavaScript and CSS front end as well as the .NET back end. The application integrated third-party integrations to output rich results processed by the system.
Freelancing Hub
https://github.com/calebrotich/Freelancers-hubA PHP-based application that connects freelancers and clients.
This application contains algorithms that enable efficient matching of job seekers with the available job opportunities.
I won developer contests with the implementation of this application.
This application contains algorithms that enable efficient matching of job seekers with the available job opportunities.
I won developer contests with the implementation of this application.
Command Line Interface Chat
https://github.com/calebrotich/cli-chatA Python command-line interface chat system meant to be added as integration to web applications that require chat services.
I led a team in building the application using Python-provided command-line tools like Click, Docopt, and Fire.
I led a team in building the application using Python-provided command-line tools like Click, Docopt, and Fire.
Bulk SMS App
https://smsleopard.com/A React-based application that enables users to send and manage promotional messages in bulk. I joined as a full-stack developer focusing on the front-end part of the application. I liaised with the back-end developer to bring in new features and improve the application's performance, security, and stability.
Skills
Languages
JavaScript, Sass, CSS, TypeScript, GraphQL, HTML, HTML5, Python, C++, Visual Basic, Java, C#, PHP
Frameworks
Next.js, Redux, Material UI, Tailwind CSS, JSON Web Tokens (JWT), Django, Jest, Cypress, NestJS, Chrome, .NET Core
Libraries/APIs
React, React Redux, REST APIs, React Router, Stripe API, React Query, Node.js, RxJS, Stripe, Playwright
Tools
GitHub, JSX, NPM, JavaScript Testing, Jira, Bitbucket, Hygraph (GraphCMS), Google Analytics, Slack, Zoom, Google Hangouts, Prisma, Flow, Sentry
Paradigms
Software Testing, Testing, Scrum, Search Engine Optimization (SEO), Design Patterns, Automated Testing, Microservices, Test-driven Development (TDD), DevOps, Unit Testing
Platforms
MacOS, Linux, Contentful, Vercel, Amazon Web Services (AWS), WordPress, Firebase, Google Cloud Platform (GCP), Visual Studio Code (VS Code), Firefox, Docker
Other
Software Engineering, Data Structures, i18n, Localization, Web Development, Content Management Systems (CMS), Responsive Web Apps, UI Testing, Front-end, User Experience (UX), User Interface (UI), Front-end Development, SaaS, Material Design, Web Usability, UI Development, Monorepos, Axios, Front-end Architecture, Front-end Design, APIs, Algorithms, Automated UI Testing, Full-stack, OAuth, Storybook, OpenAI, CI/CD Pipelines, WCAG 2, BlueJeans, MVVC, Serverless, Apollo, Server-side Rendering (SSR), Single Sign-on (SSO), Google Sign-in, Radix UI, A/B Testing, Internationalization, Security, Google Analytics 4
Storage
Google Cloud, PostgreSQL
Education
2015 - 2018
Bachelor's Degree in Information Technology
Dedan Kimathi University Of Technology - Nyeri, Kenya
Certifications
DECEMBER 2020 - PRESENT
Associate Cloud Engineer, Google Africa Developer Scholarship
SEPTEMBER 2018 - PRESENT
Mobile Web Specialist, Freelance Agency Learning Community
Freelance Agency
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