Software Engineer - Nairobi
I build it,
I QA it,
I ship it.
Full-stack engineer with roots in QA. I've shipped to production and I've sat on the other side of it — finding the edge cases before users do. Turns out, both make you better at the other.
The way I work
Engineer
I build.
Full-stack across React Native, Next.js, Node, and Postgres. I've taken a product from no-code MVP to a mobile app handling real payments for 5,000+ monthly users. I care about the code that exists after the deadline.
Quality
I break things.
Spent time as a QA engineer. Wrote test suites, filed enough Jira tickets to understand what good bug reproduction looks like, and learned exactly how software fails under real conditions. That's not a detour - it's why I write better code now.
Full-Stack, End-to-End
What I Build
End-to-end engineering - from data model to deployed product. I own the full stack and take problems to production.
Frontend Systems
I build frontends that are fast to load, straightforward to maintain, and designed around how users actually behave - not how we hope they will.
Backend & APIs
I design and implement backend systems that handle real data, real concurrency, and real edge cases - with clean APIs, proper validation, and reliable error handling.
Mobile Applications
I build React Native apps that feel native, perform well on real devices, and handle the full product lifecycle - from onboarding to payments to app store release.
Selected Work
Best in Hel
Membership & event platform - live in Helsinki
Co-founded and built a production-ready membership & event platform used by 2,500+ users and 50+ businesses - real payments, QR check-ins, iOS and Android.
PesaPlan
Personal finance clarity for salaried Kenyans
Built a personal finance web app that consolidates M-Pesa, bank, SACCO, and cash accounts into one dashboard — budgets, goals, debt tracking, and investment logging built around how Kenyans actually manage money.
Experience
Jan 2025 – Present
Full-Stack Engineer
Best in HEL · Remote, Helsinki
- -Migrated no-code MVP to React Native - now serving 8,000+ registered users
- -Built event management: ticketing, attendee flows, admin dashboard
- -Stripe integration - real payments with real-time updates
Oct 2023 – Present
QA Engineer
GRIFFIN Global Technologies
- -Owned test coverage across multiple product releases in Jira
- -Built Cypress test suite - 200+ automated tests catching regressions early
- -Bridged dev, PM, and design on bug triage and acceptance criteria
Jul 2023 – Sep 2023
QA/QE Intern
GRIFFIN Global Technologies
- -Built a scalable Next.js + .NET system with reusable modular components
- -Initiated and ran the Cypress test suite - first automated tests on the codebase
Feb 2022 – Apr 2022
IT Intern
AAR Insurance
- -Software installations, user account management, network troubleshooting
Clients & Collaborators
What People Say
Results speak louder than pitches. Here's what clients say about working with me.
“Great work quality and strong collaboration as always. Highly recommended!”
“Great developer. If you need quick clean code Brian is an excellent choice. If I ever need work done he will be my first choice.”
“Great worker who does a fantastic job. I'd highly recommend him for any future products and would collab again”
“It was our pleasure to again work with Brian. Throughout the entire front-end design process for the LoftLime website, Brian exhibited a remarkable level of diligence, coordination, and attention to detail. Not only did Brian deliver outstanding design work, but his meticulous testing and quality assurance efforts also ensured a flawless user experience. His commitment to delivering a high-quality product was evident in every aspect of his work. It was a pleasure collaborating with Brian, and I... more”
“It's always a pleasure to work with Brian. He delivered a sleek and user-friendly landing page within the deadline, showcasing his professionalism and dedication. Brian's dedication and attention to detail truly shine through in his work. Looking forward to our future collaborations!”
“Brian is just more than awesome. He completed the task as expected on time with the good quality delivered. Would love to work again in the future!”
Contact
Working on something worth building?Let's talk.
Brian Kalusi
Ships code. Logs bugs. Sleeps just fine.