Kevin O.

Senior Software Engineer

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Nairobi, Kenya

Experience

Sep 2021 - Aug 2025
4 years
Nairobi, Kenya

Senior Software Engineer

AZA Finance

  • Designed and implemented scalable, secure API integrations with financial institutions, processing 1M+ transactions/month and enabling $10M in revenue by improving pipeline reliability and success rates by 25%.
  • Designed a high-traffic API infrastructure using Ruby on Rails and React, processing 1M+ monthly transactions with 25% improved success rates for crypto/FX operations.
  • Mentored and supported 3+ junior engineers through code reviews and pair programming, fostering a culture of continuous learning and improving team deployment success rates.
  • Advocated for and implemented improvements to code quality and security by leading a legacy system refactor, reducing deployment time by 25% through optimized CI/CD pipelines and comprehensive test suites (RSpec).
  • Owned end-to-end integration with banking partners and money transfer operators (MTOs), designing reliable payment pipelines that reduced client integration time by 25% and streamlined cross-border fund disbursement.
  • Collaborated with external developers and cross-functional teams to improve product usability, reducing client API integration time by 25% through clear documentation and streamlined processes.
  • Documented over 10 architecture designs and technical specifications, reducing onboarding and maintenance time for new developers by 15%.
  • Participated in an on-call rotation for a critical financial payments platform, assisting in troubleshooting and resolving urgent operational and security incidents to ensure system reliability.
Oct 2018 - Sep 2021
3 years
Morrisville, United States

Software Engineer

TKXS (now Telus.com)

  • Provided production support for over 5 critical systems, resolving 95% of incidents.
  • Contributed to the full software development lifecycle of multiple SaaS products using Ruby on Rails, delivering features that increased user engagement by 25%.
  • Improved system performance and scalability by optimizing PostgreSQL databases and queries, achieving 99.9% data reliability and reducing latency for end-users.
  • Ensured 98% of developed features and enhancements met performance benchmarks, improving user satisfaction scores by 10%.
  • Identified and resolved multiple bottlenecks and bugs, reducing system downtime by 40%.
  • Coordinated with project managers to plan and prioritize over multiple development cycles, achieving a 95% on-time delivery rate for new features and fixes.
  • Implemented and optimized data storage solutions across 5+ projects using PostgreSQL achieving a 99.9% data reliability rate.
Sep 2017 - Oct 2018
1 year 2 months
Kisumu, Kenya

Community Lead

Ruby Kisumu

  • Organized and led 30+ Ruby mobs and meet-ups, increasing community engagement by 40%.
  • Mentored 10+ Ruby developers on best programming practices, resulting in a 20% improvement in code quality across community projects.
May 2017 - Oct 2018
1 year 6 months
Kisumu, Kenya

Software Developer

Podii

  • Developed and maintained applications using Ruby on Rails and some javascript to power web applications, implementing features and enhancements.
  • Supported multiple features and developed new components, increasing system reliability by 15%.
  • Enhanced database performance by 40% through schema optimization, supporting scalability for 10K+ records.
  • Spearheaded the adoption of GitLab CI/CD, designing and implementing pipelines that reduced deployment times by 50%, enforced code quality standards, and automated testing for 100+ deployments.
May 2016 - Sep 2016
5 months
Kisumu, Kenya

Software Developer Intern

LakeHub

  • Developed and deployed 3+ web applications improving project completion time by 15% through efficient coding practices.
  • Participated in code reviews helping to maintain a high code quality standard and reducing the number of post-deployment issues by 15%.
  • Assisted in developing RESTful APIs for 3+ projects, facilitating smooth integration with third-party services and enhancing data exchange efficiency by 20%.

Summary

Senior Backend Engineer with 7+ years of 100% remote experience specializing in high-scale, reliable Ruby on Rails and PostgreSQL systems. Proven track record of enhancing product quality, security, and performance for applications processing 1M+ monthly transactions. A passionate advocate for test-driven development (TDD), CI/CD best practices (including GitLab CI), and asynchronous collaboration. Excels at mentoring engineers and driving continuous improvement in agile, mission-driven environments.

Languages

Swahili
Advanced
English
Intermediate

Education

Nov 2013 - Dec 2017

Masinde Muliro University of Science and Technology

Bachelor’s degree · Computer Science · Kenya

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