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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.…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

Full Stack Developer, Front-End Developer, Back-End Developer, +2

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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.…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.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

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.