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Jiacheng Yan

@jiachengyan

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Senior Full Stack Engineer specializing in React, Node.js, and scalable SaaS platform performance.

Malaysia

Message

What I'm looking for

I seek a role where I can lead high-impact SaaS engineering work, improve performance and scalability, collaborate cross-functionally, mentor engineers, and drive CI/CD and cloud infrastructure excellence.

I am a Senior Full Stack Engineer with 10+ years building and scaling SaaS platforms, focused on performance, reliability, and maintainability. I partner with product and design teams to translate requirements into production-ready solutions and mentor junior engineers.

I have driven measurable improvements including a 90% reduction in network requests via GraphQL optimization, 40% faster development through a shared component library, and database tuning that improved API response times by 37%.

My technical strengths include React/Next.js, TypeScript, Node.js, PostgreSQL/MySQL, AWS infrastructure, CI/CD automation, and testing strategies that maintain high code quality and uptime for enterprise clients.

Experience

Work history, roles, and key accomplishments

Current

Senior Full Stack Engineer

Current

Freelance / Self Employed

Jan 2024 - Present (2 years 1 month)

Architected and delivered a production-ready React component library and migrated a 15k+ line CRM to Next.js, reducing development time by 40% and improving page loads by 35%; implemented Apollo GraphQL caching to cut network requests by 90% and perceived latency from 450ms to under 50ms.

React Next.js Material UI Storybook Apollo GraphQL Performance Optimization CI CD TypeScript AWS

Full Stack Developer

Anhsin Technology Sdn. Bhd.

Oct 2023 - Dec 2023 (2 months)

Engineered full-stack features for B2B SaaS serving 10,000+ monthly users; redesigned RESTful APIs and optimized database queries to reduce average response time from 450ms to 120ms and implemented CI/CD pipelines to cut deployments from 45 to 15 minutes.

React TypeScript Express NestJS PostgreSQL Docker GitHub Actions AWS

Software Developer

Witty Data Sdn. Bhd.

Nov 2017 - Jun 2023 (5 years 7 months)

Delivered 6+ enterprise web applications and deployed microservices handling 50,000+ daily API requests; optimized SQL queries to cut processing time by 30% and raised Lighthouse scores from 65 to 92, improving UX for 20,000+ end users.

React TypeScript Microservices PostgreSQL MySQL Performance Tuning API Design

Software Developer

Atos

Feb 2015 - Oct 2017 (2 years 8 months)

Developed responsive web applications for banking clients, integrating frontends with RESTful APIs to serve 5,000+ users and improving user satisfaction scores by 22% through robust error handling and loading states.

React Javascript (ES6)CSS3 RESTful APIs Responsive Design Cross Browser Testing SDLC Error Handling

Internship Trainee

Atos

Oct 2014 - Dec 2014 (2 months)

Supported mainframe and AS/400 operations including batch job scheduling with Tivoli Workload Scheduler and orchestrated incident response, resolving 7+ production incidents monthly and maintaining 99.9% system availability.

AS 400 Incident Response Monitoring Production Support System Availability

Education

Degrees, certifications, and relevant coursework

Universiti Tunku Abdul Rahman

Bachelor of Engineering, Computer Software Engineering

2012 - 2015

Bachelor of Engineering in Computer Software Engineering with focus on software architecture, database systems, and web technologies completed between 2012 and 2015.