Full-Stack
Developer
& AI Engineer
I build offline-first software, AI-powered tools, and mobile products for environments where connectivity and compute are limited — not assumed.
Alexander Appiah-Kubi
Who I Am
I'm a full-stack developer from Kumasi and the founder of Lextech Solutions. I build production software specifically for the African market — things that work on slow networks, old phones, and tight budgets.
My work spans the whole stack: architecture, backend APIs, frontend UX, Flutter mobile apps, and deployment. I care about security, maintainability, and shipping things that actually run.
Frontend
Mobile
Backend & Databases
AI & LLMs
DevOps & Security
Services
Web Development
Full-stack web apps built with React, Next.js, and FastAPI. From landing pages to multi-service platforms — clean code, fast load times, and proper architecture.
- React / Next.js frontends
- FastAPI & Node.js backends
- PostgreSQL, Redis, Supabase
- Auth, roles & API security
Mobile Apps
Cross-platform Flutter apps built for real-world conditions. Offline-first data sync, mobile money integrations, and smooth UX on mid-range Android devices.
- Flutter (iOS & Android)
- Offline-first with SQLite/Hive
- BLoC / GetX state management
- MoMo & payment integrations
AI Integration
Practical AI features shipped into your product — not demos. RAG pipelines, local LLMs via Ollama, voice transcription with Whisper, and vector search with Qdrant.
- RAG & semantic search
- Local LLM deployment
- OpenAI / Gemini API wrappers
- Speech-to-text pipelines
Security & DevOps
Hardening, CI/CD pipelines, and penetration testing for production systems. I build and audit secure systems — JWT, TOTP, encrypted storage, and Docker deployments.
- Penetration testing
- JWT / TOTP auth systems
- Docker & CI/CD pipelines
- Vercel & Railway deployments
My Process
Discover
We start with a proper conversation — your users, your constraints, your market. I ask a lot of questions before writing a single line of code.
Architect
I design the system before building it — data models, API contracts, auth flows, and deployment plan. No surprises at the end.
Build
Iterative development with regular check-ins. You see working software early — not at the final handoff.
Ship & Support
Deployment, monitoring, and documentation. I don't disappear after launch — I make sure things actually run in production.
Projects
PlayMe
Stream the latest movies, trending TV shows, and exclusive anime. A high-performance streaming interface with responsive categorization.
dir. trigger
Professional photography and cinematic storytelling portfolio. High-fidelity visual showcase for media production services.
Lextech
Production-grade collaboration platform. 9-service FastAPI backend, PostgreSQL 16, Redis, Next.js frontend with offline sync Flutter app.
Lemaire Clothing App
Feature-complete client measurement system. Live search, tracking, and SVG body diagrams tailored for the atelier industry.
Benny Homes
A modern real estate platform focused on premium listings and property viewing schedules.
Dots iCare
Streamlined health service platform combining elegant user interface with comprehensive access features.
Also check out: Lindberg Autos, Green Focus
Case Studies
Lextech — A 9-Service Collaboration Platform
Challenge: A growing team needed an internal platform that handled real-time collaboration, document management, project tracking, and payments — all in one place, with zero reliance on expensive SaaS tools.
Solution: Built a microservices architecture with 9 FastAPI services, a Next.js frontend, PostgreSQL 16 with row-level security, Redis caching, and a companion offline-sync Flutter mobile app.
Lemaire — Client Measurement System for a Fashion Atelier
Challenge: A tailor was managing hundreds of client measurements in notebooks and scattered spreadsheets. Finding a client's data before a fitting took minutes and led to frequent errors.
Solution: Built a web app with live search, full CRUD for measurements, visual SVG body diagrams per client, and a Supabase backend. The tailor can now find any client in under 2 seconds.
Sentinel Suite — Internal Security & Audit Tooling
Challenge: Lextech's growing codebase needed a structured approach to security auditing, credential management, and access control — without relying on expensive third-party tools.
Solution: Developed an internal security suite covering JWT/TOTP auth hardening, encrypted credential storage, role-based access control, and automated penetration test scripts targeting common API vulnerabilities.
Testimonials
Lexa built our entire collaboration platform from scratch. What impressed me most was that he thought about scalability before we even asked — the system handled 3x our expected load from day one.
He digitized our entire measurement system in two weeks. Now I can pull up any client's history in seconds instead of digging through notebooks. My fittings run much smoother.
Working with Alexander felt like working with a senior engineer from a top tech company. He communicated clearly, hit every deadline, and the code is actually clean and maintainable.