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I’m a software engineer with 6+ years of experience building scalable applications end to end, with strong focus on Java and Spring Boot services as well as React-based frontends. I enjoy turning product requirements into clean, maintainable code using Agile practices, SOLID principles, and reliable engineering workflows. Across my roles, I’ve worked on REST APIs, cloud-based microservices, and performance optimization—such as improving PostgreSQL query performance and enhancing application scalability. I also bring a quality-first mindset with strong unit-test coverage and CI pipelines, and I regularly use AI-assisted workflows (like Claude) to boost efficiency and improve code and test generation.…I’m a software engineer with 6+ years of experience building scalable applications end to end, with strong focus on Java and Spring Boot services as well as React-based frontends. I enjoy turning product requirements into clean, maintainable code using Agile practices, SOLID principles, and reliable engineering workflows. Across my roles, I’ve worked on REST APIs, cloud-based microservices, and performance optimization—such as improving PostgreSQL query performance and enhancing application scalability. I also bring a quality-first mindset with strong unit-test coverage and CI pipelines, and I regularly use AI-assisted workflows (like Claude) to boost efficiency and improve code and test generation.

Mathews Okeyo

Front-End Developer, Back-End Developer, Full Stack Developer, +5

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I’m a software engineer with 6+ years of experience building scalable applications end to end, with strong focus on Java and Spring Boot services as well as React-based frontends. I enjoy turning product requirements into clean, maintainable code using Agile practices, SOLID principles, and reliable engineering workflows. Across my roles, I’ve worked on REST APIs, cloud-based microservices, and performance optimization—such as improving PostgreSQL query performance and enhancing application scalability. I also bring a quality-first mindset with strong unit-test coverage and CI pipelines, and I regularly use AI-assisted workflows (like Claude) to boost efficiency and improve code and test generation.…I’m a software engineer with 6+ years of experience building scalable applications end to end, with strong focus on Java and Spring Boot services as well as React-based frontends. I enjoy turning product requirements into clean, maintainable code using Agile practices, SOLID principles, and reliable engineering workflows. Across my roles, I’ve worked on REST APIs, cloud-based microservices, and performance optimization—such as improving PostgreSQL query performance and enhancing application scalability. I also bring a quality-first mindset with strong unit-test coverage and CI pipelines, and I regularly use AI-assisted workflows (like Claude) to boost efficiency and improve code and test generation.

Available to hire

I’m a software engineer with 6+ years of experience building scalable applications end to end, with strong focus on Java and Spring Boot services as well as React-based frontends. I enjoy turning product requirements into clean, maintainable code using Agile practices, SOLID principles, and reliable engineering workflows.

Across my roles, I’ve worked on REST APIs, cloud-based microservices, and performance optimization—such as improving PostgreSQL query performance and enhancing application scalability. I also bring a quality-first mindset with strong unit-test coverage and CI pipelines, and I regularly use AI-assisted workflows (like Claude) to boost efficiency and improve code and test generation.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Language

English

Fluent

French

Advanced

German

Intermediate

Work Experience

Software Engineer (Team Lead) at Mobile Commons, Geneva, Switzerland

July 1, 2025 - Present

Lead the Survey Builder project, enabling clients to create custom surveys sent to their customers. Helped architect the survey system using IndexedDB to reduce database load and improve responsiveness. Built and maintained SaaS features across frontend and backend using React, TypeScript, and Java Spring Boot, applying SOLID and clean code practices in development and reviews. Improved PostgreSQL query performance via indexing and query optimization, reducing query response times by 40%, and enhanced backend services and REST API endpoints to improve scalability and performance by 20%. Maintained 90%+ unit test coverage using SonarQube and Jenkins CI pipelines, and improved development productivity with AI-assisted workflows (e.g., Claude) and AI tooling for documentation and ticket management. Supported engineering quality through peer code reviews and automated review workflows (e.g., CodeRabbit).

Software Engineer at Upland Software, Geneva, Switzerland

August 1, 2022 - July 1, 2025

Developed customer-facing web application features using React, JavaScript, and TypeScript. Resolved large-data export issues involving AWS Lambda timeouts and implemented query optimization strategies along with API Gateway GZIP compression and adaptive batching. Collaborated with UX designers, QA engineers, and project managers to deliver business-critical software. Communicated and documented technical concepts to non-technical stakeholders. Implemented end-to-end tests with Selenium to support development and release processes and participated in integration testing with QA.

Software Engineer at Upland Software

August 1, 2022 - Present

Front-end development with React and TypeScript to build new customer-facing web products; back-end development with Java Spring Boot to create REST API endpoints and optimize existing APIs for the frontend; wrote clean, tested code with unit tests targeting ≥90% coverage; SonarQube used in Jenkins pipelines for code quality; collaborated with UX designers, QA, and PMs to deliver desirable software; implemented API gateway g-zipping to fetch large data sets on AWS Lambda; conducted code reviews to promote consistency; improved PostgreSQL performance through query optimization and indexing; used Docker to build, test, and deploy microservices on AWS.

Software Engineer at Lucy Electric, Basildon, UK

November 1, 2019 - August 1, 2022

Enhanced a React Native mobile application using Redux to communicate with substation hardware and troubleshoot connectivity issues related to Ethernet. Developed and maintained a C# Windows application, delivering incremental improvements based on customer requirements. Implemented Apache Kafka messaging with MuleSoft to process and analyze streaming data in real time.

Software Engineer at Lucy Electric

November 1, 2019 - August 1, 2022

Improved functionality of React Native mobile app to increase user engagement, refining UI and processing speed with Redux and reduced hardware calls; developed a C# Windows app with incremental updates and a software release report to communicate updates to customers; developed u-blox modem control with AT commands for embedded systems; participated in full software development process including planning, analysis, design, development, testing, deployment, and maintenance for demo projects with Arduino and third-party devices; implemented Apache Kafka on MuleSoft to analyze and process streaming data in real-time.