Looking for a job

Celmo Moss

@celmo_mosse

Message

Full stack developer.

Angola

Message

What I'm looking for

I am looking for a collaborative environment that fosters innovation and growth.

Backend engineer with over four years building APIs and distributed services in Node.js, TypeScript, Rust and C#/.NET, with PostgreSQL,

MongoDB, Docker and AWS running in production. I also trained as a mechatronics engineer, so I am at home with Siemens S7 PLCs, TIA

Portal, SCADA/HMI, instrumentation and CAD, and I have done real maintenance, fabrication and electronics work. I write production

software and understand the machines it runs on.

Experience

Work history, roles, and key accomplishments

Current

Founder & Full Stack Developer

Current

CareerCoachAI

Feb 2026 - Present (8 months)

Built and launched an AI job-search platform on my own in three months, using Next.js 16, React 19, TypeScript, and Tailwind CSS 4. Set up Firebase Auth, Firestore, and Firebase Storage, and integrated Groq, Paddle, Resend, and Vercel.

Next.js React TypeScript Tailwind Firebase Auth Firestore Firebase Storage GROQ LLaMA 3.3 70B Paddle Resend Vercel Jest Testing Library

Current

Backend Developer

Current

Upwork

Feb 2021 - Present (5 years 8 months)

Built a modular MongoDB schema for an e-commerce platform, optimizing read performance by ~40%. Created a Jest unit testing suite with 85%+ code coverage, improving backend reliability and catching edge-case bugs early. Deployed services in Docker containers and automated deployments via GitHub Actions and AWS EC2.

Node Django ASP.NET SQL MySQL PostgreSQL MongoDB Authentication Authorization REST APIs

Current

Front End Web Developer

Current

Upwork

Feb 2021 - Present (5 years 8 months)

Designed and implemented responsive UIs with Tailwind CSS and Sass, ensuring pixel-perfect rendering across desktop and mobile devices. Developed reusable component libraries, reducing development time for future projects by ~25%. Integrated external REST APIs and implemented error boundaries for graceful data loading.

HTML CSS JavaScript React Angular Vue.Js Redux Responsive Design

Junior Application Developer

Sedna

Apr 2025 - Jan 2026 (9 months)

Migrated backend Web APIs from C#/.NET to Rust, improving throughput on high volumes of asynchronous requests. Integrated RabbitMQ for reliable messaging between decoupled microservices and optimized PostgreSQL queries and indexing.

C#.NET Rust RabbitMQ AMQP PostgreSQL OAuth Secure Development

Engineering Internship

Cape Peninsula University of Technology

Jul 2025 - Dec 2025 (5 months)

Carried out preventive maintenance and fault diagnosis on lathe machines, and brought a non-functioning lathe back to full working condition. Performed welding, fabrication, and electrical or electronic repair across a range of equipment.

Preventive Maintenance Fault Diagnosis Mechanical Repair Welding Fabrication Electrical Repair Sheet Metal Cutting

Software Engineer

Independent Contractor

Feb 2024 - Apr 2025 (1 year 2 months)

Lifted platform performance by 25% and cut API latency by 30% through refactoring and query optimisation.

Performance Optimization Refactoring Query Optimization

Full Stack Developer

Upwork

Feb 2021 - Dec 2024 (3 years 10 months)

Built and scaled RESTful APIs with Node.js and Express serving more than 10,000 daily active users. Added JWT authentication and RBAC, and reworked MongoDB schema design to improve read performance by 40%.