AYODEJI OLANREWAJU DANIEL

Backend Developer | Software Engineer | Data Enthusiast

Hi, I'm Ayodeji Olanrewaju Daniel, also known as GdAyo.

I'm a Backend Developer focused on building APIs, backend services, data-driven applications, and systems that solve practical problems.

My development journey started with learning programming fundamentals and gradually moved into building real applications with Go and Python. I now work with databases, authentication, HTTP servers, Docker, APIs, and backend architecture.

I learn best by building things, breaking them, debugging them, and understanding why they work.

My current interests include:

• 🏗️ Backend engineering
• 🔌 REST API development
• 🗄️ Database design and SQL
• 🔐 Authentication and authorization
• 🐳 Docker and development environments
• 🐍 Python backend development
• 📊 Data analysis and statistics
• 🌐 Open-source development
• 🧠 Algorithms and problem solving
• ⚙️ System design and scalability

I've moved from building small standalone programs to building complete backend systems.

Currently, I'm focused on understanding how the different parts of a real application connect:

Client
   ↓
HTTP Request
   ↓
API / Router
   ↓
Middleware
   ↓
Controller / Handler
   ↓
Business Logic
   ↓
Database
   ↓
Response

I'm also learning how to make these systems more reliable through:

• Authentication
• Authorization
• Input validation
• Error handling
• Database relationships
• Transactions
• Middleware
• API structure
• Containerization
• Debugging
• Testing
• Documentation
• System design

• REST APIs
• HTTP servers
• Routing
• Middleware
• JWT authentication
• Request validation
• JSON processing
• Database integration
• PostgreSQL
• pgx
• CLI applications
• File processing
• Error handling
• Modular application structure

• Backend development
• Data processing
• Data analysis
• Pandas
• NumPy
• API development
• Automation
• Scripting

• PostgreSQL
• SQLite
• SQL
• Relational database design
• Foreign keys
• Relationships
• CRUD operations
• Aggregations
• Database queries
• Data validation

I'm actively developing my understanding of:

• REST architecture
• Authentication
• Authorization
• JWT
• Middleware
• Request/response lifecycle
• API design
• Validation
• Error handling
• Database transactions
• Concurrency
• Data consistency
• System reliability
• Scalability

A backend API designed around personal finance management.

The system focuses on managing:

• Users
• Authentication
• Transactions
• Budgets
• Savings goals
• Contributions
• Financial data

• Go
• PostgreSQL
• Docker
• JWT
• REST API
• Gin
• SQL

• Authentication
• Middleware
• Database relationships
• CRUD operations
• Financial calculations
• Input validation
• Error handling
• API architecture
• Dockerized development

This project represents my transition from learning individual backend concepts to connecting them into a complete backend application.

A Go application that converts normal text into ASCII-styled output.

Features include:

• Multiple banner styles
• Text processing
• Alignment
• File output
• CLI flags
• HTTP server
• Web interface

• Go fundamentals
• String manipulation
• File processing
• CLI development
• HTTP servers
• Request handling
• Project structure

A text-processing application written in Go.

It processes text files and performs operations such as:

• Punctuation correction
• Word capitalization
• Binary conversion
• Hexadecimal conversion
• Text transformation

• Algorithms
• String processing
• File I/O
• Parsing
• Regular expressions
• Go fundamentals

VoiceOrder is an early experiment in ordering food by speaking instead of typing. I'm building a small FastAPI endpoint that accepts an audio file and returns a transcript, and comparing speech recognition with Vosk and Whisper.

It's still a prototype: the next challenge is making the transcript reliable and useful for matching actual menu items, not just turning speech into text.

• Python
• FastAPI
• Whisper
• Vosk

Tandem is a language-learning MVP for couples to practice together, play short quizzes, and save phrases they want to remember. The site is live on GitHub Pages.

I've been working on the app foundation too: adding automated checks, organizing the frontend, and preparing versioned Supabase migrations and shared progress features. Cloud sync still needs a Supabase project to be configured; until then, practice and saved phrases stay in the current browser.

• TypeScript and JavaScript
• Supabase
• Vite
• GitHub Actions

I also work with datasets to understand patterns and generate useful insights.

Typical workflow:

Raw Data
   ↓
Data Cleaning
   ↓
Data Transformation
   ↓
Exploratory Analysis
   ↓
Visualization
   ↓
Statistical Analysis
   ↓
Insights

• Python
• Pandas
• NumPy
• Jupyter
• R
• SQL

My development journey has evolved through several stages:

Programming Fundamentals
        ↓
Go & Python
        ↓
CLI Applications
        ↓
HTTP Servers
        ↓
REST APIs
        ↓
Databases
        ↓
Authentication & Middleware
        ↓
Docker
        ↓
Complete Backend Systems
        ↓
System Design & Scalability

Rather than trying to learn everything theoretically first, I prefer to build projects and learn the concepts required to make them work.

Right now I'm focused on becoming a stronger backend engineer.

• 🚀 Building better REST APIs
• 🏗️ Improving backend architecture
• 🗄️ Getting stronger with PostgreSQL and SQL
• 🔐 Understanding authentication and authorization deeply
• 🐳 Using Docker more effectively
• 🧪 Improving testing and debugging
• 📖 Learning API documentation with Swagger/OpenAPI
• ⚙️ Understanding concurrency and scalable systems
• 🌐 Contributing to open source
• 📊 Continuing to develop my data skills
• 🎙️ Improving VoiceOrder's speech-to-text ordering prototype
• 💛 Building Tandem and learning how to make its app foundation easier to maintain

I'm particularly interested in systems where there is more happening behind the scenes:

• Financial applications
• APIs
• Data processing systems
• Automation tools
• Backend services
• Developer tools
• Data-driven applications

I enjoy understanding how a request moves through a system, how data is stored, how different components communicate, and how the system behaves when things go wrong.

My goal is to continue moving from:

"I can write code."

to:

"I can design, build, debug, and maintain reliable systems."

The next stage of my journey is going deeper into:

• System design
• Distributed systems
• Concurrency
• Caching
• Queues
• Performance
• Testing
• Observability
• Cloud infrastructure
• Production backend engineering

I want to become a backend engineer capable of building reliable, scalable, and useful software systems.

I'm particularly interested in the intersection between:

Software Engineering
        +
Backend Systems
        +
Data
        +
Problem Solving

This repository documents that journey — from small experiments and coding challenges to increasingly complete backend systems.

Still building. Still learning. Still breaking things. Then fixing them. 🚀