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About

Isaac Oluwayinka

Software Engineer & Architect

I'm Isaac, a software engineer. I've been shipping production software since 2019: first as a freelancer for clients in education, e-commerce and logistics, and now as the person who leads engineering at Lone Star Civil, a construction company in San Antonio, Texas.

I didn't start in software. I studied geology at Obafemi Awolowo University, and began working as a developer in February 2019, the year I graduated.

What I do best is carry a system from the first sketch to production: the data model, the API, the interface, the cloud it runs on and the pipeline that ships it. At Lone Star Civil that means a NestJS API on PostgreSQL, hosted on AWS and deployed without downtime, with features built on the Claude API. I also build mobile apps, native Android in Kotlin and iOS in Swift.

I'm looking for a lead or senior role, full-time or on contract. I work remotely.

See what I have builtHiring? Start here

Isaac Oluwayinka, smiling with arms folded, in a dark blazer and a striped shirt

Where I have worked

  1. Neli Arabi GmbH

    Lead Backend Engineer and pod lead

    Apr 2026 to Oct 2026, Berlin, Germany (remote)

    I led a backend pod building a B2B ERP platform for complex multi-entity operations.

    • Led the pod from April to October 2026.
    • Helped build the platform's structured workflows, data control, integrations and reporting.
    • Built private enterprise review into the platform.

  2. Lone Star Civil

    IT Manager and Lead Software Engineer

    Mar 2025 to now, San Antonio, Texas (remote)

    I lead the design, build and deployment of a contractor-management platform with AI features, and I own the company's software and cloud infrastructure.

    • Run the backend on AWS ECS Fargate with Aurora Serverless v2 PostgreSQL, S3 and CodeBuild pipelines, deploying without downtime.
    • Built a NestJS and TypeScript REST API with more than 50 endpoints, JWT authentication, role-based access and per-company data isolation.
    • Added features on the Claude API: streamed answers, tool use and document processing for PDF, DOCX, XLSX and images, leading to automated bids, cost estimates and price comparison.
    • Model the data in Prisma on PostgreSQL, including schema design, query tuning and migrations for construction-domain data.

  3. TheSlimPrep

    Part-time Software Engineer

    May 2024 to Mar 2026, Canada (remote)

    I built web applications and REST APIs for several platforms on a multi-tenant architecture, alongside my full-time work.

    • Built web apps and REST APIs in Node.js and React for multiple platforms on a multi-tenant architecture.
    • Designed SQL schemas and indexes, improving data retrieval performance by 40%.
    • Set up Docker development environments and deployment workflows, which sped up onboarding and made CI/CD reproducible.
    • Added JWT authentication and role-based access to multi-tenant SaaS features.
    • Worked in a cross-functional Agile team.

  4. Independent

    Full-stack developer and consultant

    Feb 2019 to Mar 2023, Remote

    Delivered web applications for clients in education, e-commerce and logistics, from architecture to deployment.

    • Wrote custom backends in PHP with Laravel and in Node.js: authentication, admin dashboards, reporting and API integrations.
    • Deployed on AWS with DNS, SSL, Nginx and automated backups.
    • Advised small businesses on technical architecture as they moved online.

What I work with

Languages
TypeScript, JavaScript, Python, PHP, SQL, Kotlin, Swift, Bash, HTML5, CSS3
Backend
NestJS, Node.js, Express, Laravel, FastAPI
Frontend
React, Next.js, Tailwind CSS, Bootstrap, Vite
Data
PostgreSQL, MySQL, Prisma, Redis, SQLite, SQLAlchemy
Cloud and delivery
AWS, Docker, GitHub Actions, Vercel, Nginx, Render, AWS ECS Fargate, AWS Aurora, AWS S3, AWS ECR, AWS CodeBuild, AWS ALB, AWS CodePipeline
Mobile
Jetpack Compose, Room, SwiftUI, UIKit, Combine, Core Data
AI
Claude API, OpenAI API, Gemini API
Payments
Stripe, Flutterwave, Paystack
Auth and security
JWT, OAuth 2.0, RBAC
APIs and integration
REST API design, SSE streaming, Postman, Axios
Background processing
Celery, Job queues, Async task processing, Event-driven architecture
Monitoring and observability
AWS CloudWatch, Structured logging, Health checks

Where I studied

  • BSc Geology

    Obafemi Awolowo University, Ile-Ife, 2014 to 2019

Let’s talk

If you have a lead or senior role, full-time or on contract, I would like to hear about it.

Email meRead the résumé

Address: hello@ykaycode.com