Kossi Edem Dotsey
Senior Full-Stack Developer with 7+ years of experience: Flutter on mobile, Node.js, NestJS and Laravel on the backend, and DevOps for deployment. Apps published on the App Store and Google Play. Available for remote work worldwide.
Who am I?
About
I'm Kossi Edem DOTSEY, a Senior Full-Stack Developer based in Lomé, Togo, with over 7 years of experience designing and delivering end-to-end mobile applications. I work across the full development lifecycle: Flutter and Dart on mobile, Node.js, NestJS and Laravel on the backend, and DevOps for deployment (CI/CD, Docker, Linux VPS). I've published several apps on the App Store and Google Play, and led a mobile team as Tech Lead for an Irish publisher.
Languages
Interests
Technical Adaptability
Comfortable with multiple tech stacks and able to quickly adapt to any technical environment.
Technical Leadership
Code reviews, architecture decisions, and mentoring; Tech Lead at HOTSHI and founder of TECMATRIX.
Product Vision
User- and business-value oriented, capable of transforming an idea into a functional application.
Full-Stack Versatility
Skilled in developing end-to-end mobile, web, and backend applications with database integration.
My technical expertise
Skills
Mobile Development
Backend & API
Databases
DevOps & Infrastructure
Web Frontend
Tools & Others
My professional journey
Experience
Professional
Freelance Full-Stack Developer (Contract)
- School Trans: secure school transportation platform with QR code identification (iOS & Android + back office).
- End-to-end design and development, solo, of 5 interfaces: Parents app, Driver app, Admin back office, School portal, Partners space.
- Full delivery in 6 weeks (July 14 – August 25, 2026), from architecture to store release.
- Real-time bus tracking with notifications to parents at each key stage of the route.
- Secure student identification via QR code at bus boarding and drop-off.
Impact
- 5 interfaces delivered in 6 weeks, solo
- Apps published on the App Store and Google Play
Senior Mobile Developer (Contract)
- FCaudioÉdit: African audiobook and eBook publishing platform (iOS & Android).
- Migrated Flutter 3.24 to 3.41 (Dart SDK upgrade) with no regressions on existing modules.
- Redesigned the app's navigation architecture, improving fluidity, usability, and overall user experience.
- Fixed critical bugs in the purchase module that were blocking users in production.
- Implemented anti-screenshot protection for eBooks and anti-recording protection for audiobooks (iOS & Android), at the request of partner publishers.
- Replaced Firebase Dynamic Links with native deep linking, removing the Firebase dependency.
- Built a complete purchase module with affiliate codes: business logic, UI, and tests.
Impact
- Roughly 60% fewer purchase-related support tickets
- Flutter migration with no regressions
Flutter Developer & Tech Lead
- Tech Lead on the Hotshi app (iOS & Android), a professional networking platform for entrepreneurs, working with an Irish product team.
- Implemented Clean Architecture across the entire codebase with a team of 3 developers.
- Led code reviews, architecture decisions, and team work organization.
- Onboarded and mentored new developers; contributed to hiring and product decisions.
- Provided technical support and assistance to end users.
Founder & Lead Full-Stack Developer
- Developed several mobile applications and management software with production backends: mobile money payments, geolocation, real-time streaming, push notifications.
- Set up CI/CD pipelines with GitHub Actions.
- Administered Linux VPS servers with Docker and Nginx.
- Trained and supported end users.
Impact
- Deployments reduced from 2 manual hours to 5 automated minutes
- 99.5% uptime over several months
Full-Stack Web Developer
- Developed and deployed a WhatsApp Business marketing platform (360Dialog API).
- Built the authentication system.
- CSV import and management of 800,000+ contacts.
- Scheduled and published bulk advertising campaigns on WhatsApp.
- Real-time live chat between the company and its prospects.
Freelance
PrixKao
Full-stack design and development
- Local price comparison app: search by keyword, category, or photo, real-time offers from nearby sellers, price alerts.
- Direct contact with merchants via WhatsApp or phone, in-app messaging, no commission.
- Full stack: Flutter, Node.js, NestJS, database, VPS/Docker infrastructure.
Katimini
Senior Mobile Developer & DevOps
- Couples app: interactive quizzes and personalized challenges.
- 10,000+ active users, 6,000+ downloads on Google Play and 4,000+ on the App Store.
- Node.js, Express, MongoDB backend deployed with Docker, Nginx, and GitHub Actions CI/CD (iOS & Android).
Lazone
Full-Stack Mobile Developer & DevOps
- Live cinema & VOD app: live streaming and broadcast schedule.
- Ticketing via 5 mobile money providers.
- Stack: Flutter, Node.js, MongoDB, Docker, Nginx, Cloudflare, CI/CD.
Production achievements
Projects
School Trans
Secure school transportation: real-time bus tracking and student identification via QR code.
FCaudioÉdit
African audiobook and eBook publishing platform.
HOTSHI
Professional networking platform for entrepreneurs, with an Irish product team.
Katimini
Couples app: 10,000+ active users, interactive quizzes and personalized challenges.
PrixKao
Local price comparison: photo search, real-time offers, price alerts.
Lazone
Live cinema & VOD, with ticketing via 5 mobile money providers.
e-Convivial WhatsApp Marketing
WhatsApp Business marketing platform with 800,000+ contacts.
My academic background
Education & Certifications
Education
Bachelor's Degree in Software Engineering
2019 – 2020Higher National Diploma (BTS) — IT Management, Application Development track
2017 – 2019High School Diploma (Baccalauréat)
2015 – 2017Let's work together
Contact
Let's work together
Available immediately for freelance missions, remote roles, or collaborations. Drop me a line — I reply quickly.
Availability
Remote, worldwide