I build and maintain full-stack web applications, with most of my work centered around backend services, APIs, production debugging, and performance issues.

A lot of freelance projects already have something that hurts — slow endpoints, unstable behavior, deployment problems, database bottlenecks, or backend code nobody wants to touch anymore because changes keep breaking something else.

That’s usually where I step in.

• Full-stack applications using React, TypeScript, Node.js, and Python
• Backend APIs and service logic
• PostgreSQL query optimization and schema cleanup
• Redis caching for reducing unnecessary database load
• Background jobs and async processing
• Production debugging through logs and request tracing
• Refactoring backend code that became risky or difficult to maintain

• APIs behaving consistently instead of working “most of the time”
• Keeping frontend state and API behavior predictable
• Database queries staying reasonable under heavier usage
• Debugging that doesn’t turn into guessing for three hours
• Keeping deployments boring and predictable

I prefer applications that stay understandable when things go wrong.

That usually means:

• separating business logic from API and database layers
• avoiding abstractions until they solve a real problem
• adding caching only after identifying the actual bottleneck
• keeping logs readable enough to trace failures quickly

I’m generally skeptical of unnecessary complexity. I’d rather work with a straightforward application that’s easy to debug than a clever setup that becomes painful to maintain later.

React, TypeScript
Node.js, Python
PostgreSQL, Redis
Docker, deployment workflows, CI/CD pipelines

Building reliable full-stack applications, improving backend performance, and handling production issues without adding unnecessary complexity.

• Email: josephtan607@gmail.com
• GitHub: https://github.com/jsf-tan
• Portfolio: https://josephtan.vercel.app/