I'm Sofiane Chadjaa, a Full Stack Engineer with 5+ years of experience building scalable web applications, real-time systems, and high-performance APIs. I thrive on reducing latency and making data-heavy apps fast and reliable, with a track record across fintech and SaaS environments. I enjoy working across frontend, backend, and infrastructure, always focusing on performance, scalability, and maintainability. In recent roles I designed REST and GraphQL APIs, built real-time payment infrastructures, implemented caching and identity management, and led frontend architecture for multi-engineer teams. I'm comfortable with DevOps practices and automating infrastructure to accelerate delivery.

Sofiane Chadjaa

I'm Sofiane Chadjaa, a Full Stack Engineer with 5+ years of experience building scalable web applications, real-time systems, and high-performance APIs. I thrive on reducing latency and making data-heavy apps fast and reliable, with a track record across fintech and SaaS environments. I enjoy working across frontend, backend, and infrastructure, always focusing on performance, scalability, and maintainability. In recent roles I designed REST and GraphQL APIs, built real-time payment infrastructures, implemented caching and identity management, and led frontend architecture for multi-engineer teams. I'm comfortable with DevOps practices and automating infrastructure to accelerate delivery.

Available to hire

I’m Sofiane Chadjaa, a Full Stack Engineer with 5+ years of experience building scalable web applications, real-time systems, and high-performance APIs. I thrive on reducing latency and making data-heavy apps fast and reliable, with a track record across fintech and SaaS environments. I enjoy working across frontend, backend, and infrastructure, always focusing on performance, scalability, and maintainability.

In recent roles I designed REST and GraphQL APIs, built real-time payment infrastructures, implemented caching and identity management, and led frontend architecture for multi-engineer teams. I’m comfortable with DevOps practices and automating infrastructure to accelerate delivery.

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Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
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Language

Arabic
Fluent
English
Advanced
French
Intermediate

Work Experience

Software Engineer at 3S-Pay
June 1, 2024 - Present
Designed and delivered 200+ REST and GraphQL API endpoints using Node.js, Bun, and Express; built real-time communication infrastructure using Server-Sent Events, Socket.IO, and MQTT to connect 1,000+ payment terminals; integrated Keycloak and OAuth2/OIDC; implemented Redis caching reducing DB load by 90% and reducing API times from 350ms to 45ms; architected frontend features with React/Next.js; automated infra with Docker, Nginx, and SSL/TLS; built internal Chrome extension; improved Lighthouse and accessibility.
Front-End Developer at DataMaster
February 1, 2024 - February 1, 2025
Built data dashboards rendering 10,000+ row datasets with React Table and virtualization; reduced API round-trips by 40% via client-side caching with Zustand; elevated WCAG compliance and green Core Web Vitals.
Full Stack Developer (Freelance) at Remote Clients
January 1, 2020 - December 31, 2023
Delivered full-stack web applications for startups and SMBs using React, Vue.js, Node.js, and Django REST; designed and shipped REST APIs backed by PostgreSQL and MongoDB; integrated third-party services; wrote unit/integration tests with Jest and React Testing Library; collaborated with distributed teams using Git workflows and Agile/Scrum.
Full Stack Developer at Remote Clients (Freelance)
January 1, 2020 - December 31, 2023
Delivered full-stack web applications for startups and SMBs using React, Vue.js, Node.js, and Django REST. Implemented REST APIs with PostgreSQL and MongoDB, integrated third-party services, and wrote unit/integration tests with Jest and React Testing Library to reduce regressions. Collaborated with distributed teams using Git, code reviews, and Agile/Scrum.

Education

Master's in Artificial Intelligence at USTO-MB
January 1, 2021 - January 1, 2023
Bachelor's in Computer Science at USTO-MB
January 1, 2018 - January 1, 2021
Master's in Artificial Intelligence at USTO - MB
January 1, 2021 - December 31, 2023
Bachelor's in Computer Science at USTO - MB
January 1, 2018 - December 31, 2021

Qualifications

Add your qualifications or awards here.

Industry Experience

Software & Internet, Financial Services, Professional Services

Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
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