Denis is available for hire
Hire DenisDenis Bosire
Verified Expert in Engineering
Front-end and WordPress Developer
Nairobi, Nairobi County, Kenya
Toptal member since August 31, 2021
Bio
Denis is a senior full-stack developer with 12+ years of experience building high-performance websites and web applications. He specializes in WordPress (custom themes, plugins, Gutenberg/FSE), React and Next.js front ends, and scalable back-end systems using PHP and Laravel. Denis has worked with agencies and global clients across the UK, Europe, and the US, delivering reliable, production-ready solutions.
Portfolio
Toptal
JavaScript, React, NGINX, HTML, CSS, WordPress, WordPress API...
Rainmaker Digital
React, PHP 7, CSS, HTML, JavaScript, GitHub, DevOps, Webpack, Webhooks, jQuery...
Pickleball Trips
WooCommerce, WooCommerce API, Payment APIs, WordPress...
Experience
- WordPress - 10 years
- CSS - 10 years
- CSS3 - 10 years
- HTML5 - 10 years
- WordPress Themes - 9 years
- WordPress API - 4 years
- React - 3 years
- Gutenberg Editor - 2 years
Work Experience
Senior Full-stack Developer
2021 - PRESENT
Toptal
- Worked with various industry clients to develop and deliver outstanding web applications.
- Perfected my DevOps skills by onboarding clients onto different services from AWS, Azure, and DigitalOcean.
- Oversaw the launch of most of these projects that not only look and feel great but also help my clients' businesses grow.
Technologies: JavaScript, React, NGINX, HTML, CSS, WordPress, WordPress API, WordPress Plugins, WordPress Design, WordPress Themes, WordPress Rescue, Web UX, Web UI, Elementor, REST APIs, LAMP, Software Architecture, Google Tag Manager, SEO Tools, Front-end, Adobe Experience Design (XD), Responsive Web Design (RWD), Plugins, MERN Stack, Web Design, ShipStation, Stripe, WordPress SEO, WordPress Optimization, Shopify, Elegant Themes, Constant Contact API, CRM APIs, XML, Forms, Yoast SEO, User Experience (UX), WP All Import, Wordfence Security, Performance Optimization, Avada, Learning Management Systems (LMS), Page Speed Optimization, ECMAScript (ES6), Zapier, Printful, Site Speed Optimization, Design, WordPress Security, Divi, Pixel Perfect, Web
Front-end Developer
2021 - PRESENT
Rainmaker Digital
- Designed and developed new WordPress themes and plugins to match client needs.
- Served as technical support for existing clients while reporting to client service.
- Collaborated with a distributed team which required constant communication.
Technologies: React, PHP 7, CSS, HTML, JavaScript, GitHub, DevOps, Webpack, Webhooks, jQuery, Figma, WordPress, PHP, Elementor, Google Tag Manager, SEO Tools, Payment APIs, Front-end, Adobe Experience Design (XD), Responsive Web Design (RWD), WPML, MERN Stack, Web Design, Responsive Web Apps, Membership Sites, ShipStation, Stripe, WordPress SEO, WordPress Optimization, Elegant Themes, Leadership, Yoast SEO, User Experience (UX), Performance Optimization, Ninja Forms, Learning Management Systems (LMS), WordPress LMS, Page Speed Optimization, ECMAScript (ES6), Zapier, Divi, Web
Senior WooCommerce/Square Developer
2026 - 2026
Pickleball Trips
- Audited a WordPress/WooCommerce/Square integration for a boutique travel platform, isolating the root cause of failed payment callbacks and eliminating manual reconciliation overhead.
- Designed and shipped high-converting landing pages, newsletter pop-ups, and lead magnets in WordPress, powering Phase-2 conversion-rate optimization for a global tour operator.
- Translated payment-API and WordPress technical trade-offs into stakeholder briefs, enabling a non-technical founder to scope Phase-1 stabilization vs Phase-2 growth work.
- Built a custom WooCommerce deposits plugin that allows trips to be paid partially.
Technologies: WooCommerce, WooCommerce API, Payment APIs, WordPress, WooCommerce Subscriptions 2, Square, WordPress SEO, WordPress Design, WordPress Themes
WordPress Developer
2024 - 2024
El Cap LLC
- Translated client-provided designs into a fully functional, responsive WordPress website using HTML, CSS, JavaScript, and React, ensuring seamless device performance.
- Integrated custom features and functionalities using React and JavaScript, enhancing the site's interactivity and user engagement.
- Developed a user-friendly content management system within WordPress, allowing the client to quickly update and manage the website's content without technical assistance.
- Ensured site optimization through responsive design, resulting in improved mobile accessibility and faster page load times.
- Used Git for version control and Trello for project management. I also used Slack and email for easy communication with the client.
- Implemented SEO best practices within the site structure and content, enhancing search engine visibility.
- Delivered the project on time and within budget, meeting all client requirements for design accuracy, functionality, and usability.
Technologies: WordPress, WordPress Themes, WordPress Plugins, WordPress Design, PHP, Web Design, Web
WordPress Developer
2024 - 2024
Serve The Need Organization
- Developed a payment gateway to accept donations easily.
- Tracked and reported bugs using Twilio and Slack and used Google page speed for speed optimization.
- Oversaw the launch of the new donation platform with a new payment platform.
Technologies: Online Payments, WordPress, Stripe, Payment APIs, PayPal API, Web
Back-end WordPress Expert
2024 - 2024
Crow Hill Productions Limited
- Developed a WordPress plugin that syncs unregistered users with downloads and matches them with registered users or creates new users and matches them with a custom order.
- Tracked and fixed issues using Slack and Twilio. The custom plugin also logged in all entries for easy debugging.
- Maintained the website when it went offline due to an increase in orders.
Technologies: WordPress, WordPress Plugins, WordPress API, Drip Email, Drip Campaigns, Design
WordPress Developer
2024 - 2024
Utah Pork Producers Association
- Migrated a WordPress site to the latest version.
- Fixed issues with outdated themes and plugins after a PHP and WordPress update.
- Oversaw the relaunch of this organization's website with an updated back end.
Technologies: WordPress, MySQL, WordPress Themes, WordPress Design, WordPress Migration
Senior WordPress Developer
2023 - 2023
Lumiform GmbH
- Helped migrate their website from a custom CMS to WordPress by building a WordPress theme, five Elementor add-ons, and three Gutenberg blocks.
- Tracked and fixed bugs using ClickUp. Also used Slack for team communication and updates.
- Oversaw a partial launch with the WordPress theme and checklist features built.
Technologies: WordPress, Elementor, Search Engine Optimization (SEO), Adobe Experience Design (XD), Plugins, WPML, MERN Stack, Web Design, Responsive Web Apps, Membership Sites, Stripe, Forms, Wordfence Security, Performance Optimization, Learning Management Systems (LMS), Design
WordPress Developer
2023 - 2023
fourth dimension technologies Inc.
- Redesigned the front-end site and optimized performance.
- Audited queries to determine where we could improve.
- Got a page speed score from a low 25 to 82 and accessibility and SEO from 30 to 99.
Technologies: WordPress, WooCommerce, Payment Processing, Websites, Performance, Software Architecture, Accessibility, Adobe Experience Design (XD), MERN Stack, Web Design, Responsive Web Apps, Stripe, WordPress SEO, Leadership, WP Engine, Learning Management Systems (LMS), WordPress LMS, Zapier
WordPress Developer
2022 - 2022
Innersource Unlimited, Ltd
- Designed and developed an e-learning platform for the Eden method and migrated from a legacy system to LearnDash.
- Used Jira to track and record bugs, GitHub for versioning, and DigitalOcean.
- Launched an e-learning platform with over 40,000 users.
Technologies: WordPress, LearnDash, ActiveCampaign, Beaver Builder, Content Marketing Platforms, WordPress API, WordPress Themes, WordPress Plugins, Elementor, jQuery, Google Tag Manager, Adobe Experience Design (XD), Membership Sites, ShipStation, Yoast SEO, User Experience (UX), Learning Management Systems (LMS), Zapier, Divi
WooCommerce Developer
2021 - 2021
Jasper Software, Inc
- Helped build an eCommerce platform for the Master's Tournament using WordPress and eCommerce.
- Tracked and fixed bugs using Trello. Used Slack for communication and to keep track of things.
- Helped re-align the development process by using Git pipelines.
Technologies: CSS, JavaScript, PHP, WooCommerce, WordPress, jQuery, Figma, Google Tag Manager, Payment APIs, Accessibility, WordPress SEO, SQL
Senior Full-stack Developer
2021 - 2021
SwishFolio
- Developed a SaaS for a client on a very limited time schedule. It was a multi-tenant app that enabled users to build portfolio websites.
- Integrated payment platforms, including Stripe and Mobile Money (M-Pesa).
- Created over 10 templates with React used to onboard clients.
- Managed all DevOps from the ground up and wrote technical documentation.
- Managed a team that included five developers, a designer, and a project manager.
Technologies: React, DevOps, GitOps, Agile Project Management, HTML5, CSS, PHP 7, SaaS, PHP, APIs, REST APIs, CSS3 Animation, Plugins, Membership Sites, Stripe, Leadership, Yoast SEO, Content Delivery Networks (CDN)
Full-stack Developer
2019 - 2019
Make Do
- Built native Gutenberg blocks, using React and then using ACF.
- Tracked and fixed bugs on projects using Jira and Bitbucket.
- Communicated in a variety of ways with a distributed team to stay on top of the project.
Technologies: React, WordPress, PHP 7, CSS, SaaS, HTML5, Testing, CSS3 Animation, Responsive Web Design (RWD), Plugins, Healthcare IT, Content Delivery Networks (CDN)
Senior Full-stack Developer
2016 - 2019
Pixel Tribe
- Built 25+ custom WordPress themes and plugins, all available for free on Wporg.com with over 600,000 active users.
- Built web apps and 50+ responsive websites for a variety of clients and agencies from design to development.
- Handled tech support, maintenance, upgrades, and DevOps.
- Brought in and maintained new clients through strategic business development approaches.
Technologies: JavaScript, React, WordPress, REST, NPM, SaaS, WooCommerce, Easy Digital Downloads, CSS3 Animation, Leadership, SQL
Web Developer
2013 - 2015
Agency Africa
- Developed an app for hotel bookings that integrates with their offline services.
- Conducted SEO and digital marketing for hotels and the hospitality industry.
- Developed and managed web apps for clients around the country.
- Customized and maintained OSS to the client's specifications and needs.
Technologies: SEO Audits, WordPress, WordPress API, Healthcare IT, SQL
Intern Front-end Developer
2011 - 2011
Magpie Agency
- Worked as the 1st tech hire in the company and managed everything pertaining to code.
- Developed web applications and websites for the hospitality industry and honed my project management skills in the process.
- Interacted with clients for strategic meetings and planning sessions.
Technologies: WordPress, Photoshop 7, HTML, CSS
Project History
Swish Backup & Migration Plugin
https://swishbackup.swishfolio.com/Swish Migrate and Backup is a powerful WordPress plugin that allows you to create full backups of your website, including the database, plugins, themes, uploads, and core files. It supports multiple cloud storage providers and makes site migration seamless.
Cooper Health
For the Cooper University Health Care website redesign project, I collaborated with Eastern Standard as a front-end and Drupal developer to modernize a large-scale healthcare platform focused on accessibility, usability, and scalability. The project involved rebuilding the digital experience in Drupal 10 while ensuring patients and visitors could easily access critical healthcare information across all devices.
I developed a component-driven front end using Drupal 10, Twig, SCSS, and JavaScript, translating Figma designs into reusable, editor-friendly components integrated with Drupal Paragraphs and Layout Builder. I also contributed to scalable content structures that balanced design consistency with editorial flexibility.
On the front end, I implemented modular SCSS architecture, responsive layouts, and interactive functionality using Drupal behaviors. Performance optimization and accessibility were key priorities throughout the project, including WCAG compliance.
The final result was a modern, maintainable healthcare platform that improved responsiveness, content management workflows, and overall user experience while providing a scalable Drupal 10 foundation for future growth.
I developed a component-driven front end using Drupal 10, Twig, SCSS, and JavaScript, translating Figma designs into reusable, editor-friendly components integrated with Drupal Paragraphs and Layout Builder. I also contributed to scalable content structures that balanced design consistency with editorial flexibility.
On the front end, I implemented modular SCSS architecture, responsive layouts, and interactive functionality using Drupal behaviors. Performance optimization and accessibility were key priorities throughout the project, including WCAG compliance.
The final result was a modern, maintainable healthcare platform that improved responsiveness, content management workflows, and overall user experience while providing a scalable Drupal 10 foundation for future growth.
The Bar Method Gym
https://barmethod.com/Build a franchise site for The Bar Method, a popular gym franchise in the States. I used Gutenberg (React) to build a full site and edit themes and plugins, including custom blocks and block patterns. The site also required a custom form and a mapping Gutenberg block that fetches and sends data to an external service via REST API.
Company Website
https://www.incentro.com/en-ke/Built the company website for Incentro. This was the 1st headless project I developed. It was built on Gatsby, CSS3, and HTML5. The back end still runs on WordPress and WordPress REST API. We later changed this to WPGraphQL.
WordPress Themes and Plugins
A WordPress themes and plugins shop specializing in real estate and portfolio themes, where ee have 17 free WordPress themes on the WordPress.org repository and five free plugins. Together with the free articles, we also have premium plugins that add more features to these themes.
WordPress Portfolio Themes
WordPress themes for photographers, designers, and artists to display their work and I built multiple themes that can be customized, as well as a Gutenberg portfolio block with a gallery, portfolio listing, and other blocks.
Lysa Magazine Africa
Built an online fashion magazine for the African market where the responsive SEO website was based on WordPress with marketing integration, such as Mailchimp and social sharing. At one point, it was the most popular fashion blog in Kenya.
Isoko
A WordPress and WooCommerce-based web app that allows small businesses to set up eCommerce sites in minutes with no technical knowledge or steps included. The sites run on WordPress Multisite hosted on AWS with load balancing and CDN.
Education
2008 - 2011
Bachelor of Science Degree in Pharmacology
University Of Leeds - Leeds, UK
Skills
Libraries/APIs
WordPress API, Stripe, jQuery, React, REST APIs, Constant Contact API, PayPal API, Flexbox, WooCommerce API
Tools
Advanced Custom Fields (ACF), Adobe Experience Design (XD), Zapier, Gutenberg Editor, Git, GitLab, GitHub, LearnDash, GravityView, Google Analytics, WPML, ShipStation, WP All Import, Ninja Forms, Photoshop 7, NPM, Webpack, Mailchimp, NGINX, Figma, Printful
Languages
HTML, CSS, PHP 7, HTML5, CSS3, PHP, XML, ECMAScript (ES6), JavaScript, SQL
Frameworks
Divi, Next.js
Paradigms
Mobile Web Design, Responsive Web Design (RWD), Web UX Design, Search Engine Optimization (SEO), REST, Testing, DevOps, Agile Project Management
Platforms
WordPress, WooCommerce, cPanel, DigitalOcean, WordPress Theme Design, Web, Shopify, HubSpot, WordPress VIP, LAMP, Drupal 8, Drupal
Industry Expertise
Web Design
Storage
MySQL, WP Engine
Other
WordPress Themes, WordPress Plugins, PSD to HTML, PSD to PHP, Web Development, Web Template Design, Responsiveness, Responsive Design, eCommerce, WordPress Design, Elementor, PSD to WordPress, Software Architecture, Front-end, Plugins, MERN Stack, Responsive Web Apps, News, Membership Sites, WordPress SEO, WordPress Optimization, Elegant Themes, CRM APIs, Forms, Yoast SEO, Performance Optimization, Cloudflare, Online Payments, Learning Management Systems (LMS), WordPress LMS, Page Speed Optimization, Content Delivery Networks (CDN), API Integration, WordPress Migration, Site Speed Optimization, Application State Management, Design, WordPress Security, Pixel Perfect, Analytics, APIs, WooCommerce Subscriptions 2, MemberPress, Gravity Forms, Google Tag Manager, SEO Tools, Payment APIs, Accessibility, CSS3 Animation, Healthcare IT, User Interface (UI), Pop-ups, Leadership, User Experience (UX), Wordfence Security, CI/CD Pipelines, Avada, Drip Email, SEO Audits, SaaS, GitOps, Gatsby, PayPal, Easy Digital Downloads, ActiveCampaign, Beaver Builder, WordPress Rescue, Webhooks, Web UX, Web UI, Content Marketing Platforms, Payment Processing, Websites, Performance, Drip Campaigns, Back-end, Square
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