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derrick User

@derrickuser3

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I’m a Java software engineer building scalable, secure backend systems with strong SDET and cloud reliability.

Kenya

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What I'm looking for

I’m looking for a team where I can build scalable, secure backend and cloud services, own end-to-end delivery, and strengthen reliability and quality through TDD, CI/CD, and proactive security.

I’m a Java Software Engineer II with 5+ years of experience designing and maintaining scalable, secure backend systems, integrating complex services with network security protocols, and optimizing for high availability in Linux-based environments. At TomTom, I took full ownership of mission-critical Map Editing and Map Viewer backend services end-to-end, delivering automated testing, CI/CD pipelines, and SLA/SLO management that resulted in 99.9% uptime.

I also improve reliability and security through incident response and root-cause analysis, dashboards and automated alerting to reduce mean time to detection, and zero downtime migrations that protect sensitive data integrity. Earlier, at Safaricom PLC (Vodafone Kenya), I built and optimized Java microservices for high-volume payment workflows, and as an SDET I architected Safaricom’s first enterprise automated testing framework, integrating functional, API, performance, and security tests into Jenkins and Azure DevOps pipelines while improving test coverage by 30%.

Experience

Work history, roles, and key accomplishments

Software Engineer II

TomTom

Nov 2024 - Sep 2025 (10 months)

Owned end-to-end backend services for mission-critical Map Editing and Map Viewer platforms, ensuring production readiness through automated testing and CI/CD with SLA/SLO management and 99.9% uptime. Improved container delivery pipelines (Docker/Kubernetes), led incident response and RCA with observability dashboards, and executed zero-downtime migrations for large-scale map editing databases.

Java Backend Development CI CD Automated Testing SLA Management Docker Kubernetes Security Hardening Incident Response Root Cause Analysis Observability Dashboards Data Integrity

Software Engineer

TomTom

Nov 2021 - Nov 2024 (3 years)

Developed and maintained core features for a mission-critical Map Editing platform, supporting high-quality UI/UX and backend stability. Optimized Docker/Kubernetes CI/CD pipelines to enable blue/green and canary deployment strategies and implemented Playwright-based E-to-E, system, and smoke tests.

Docker Kubernetes CI CD Blue Green Deployment Canary Releases Playwright Automated Testing

Software Engineer

Safaricom PLC (Vodafone Kenya)

Jan 2021 - Nov 2021 (10 months)

Built and optimized high-performance Java microservices supporting M-PESA payment workflows, mobile data platforms, and cross-border integrations at scale with security and reliability focus. Tuned database access patterns to reduce latency during traffic spikes and delivered a microservices testing framework with automated quality gates to reduce production defects and improve velocity.

Java Microservices Performance Tuning SQL Tuning Indexing API Performance Testing Frameworks Quality Gates

Software Engineer in Test (SDET)

Safaricom PLC (Vodafone Kenya)

Sep 2018 - Jan 2021 (2 years 4 months)

Architected and delivered Safaricom’s first enterprise automated testing framework, increasing test coverage by 30% and removing critical bottlenecks in the release cycle. Integrated automated functional, API, performance, and security tests into Jenkins and Azure DevOps pipelines, and built a unified test data lake with Power BI dashboards to improve visibility and defect management.