Live- Custom Build
- Marketplace
Rent N Roll
Integrated payment and deposit handling through PayMongo webhooks.
John Lester Escarlan
Full-Stack Software Engineer
I help product teams ship full-stack features, fix production bottlenecks, and replace fragile manual workflows with tested automation.
Impact
A few results from my work.
- 25+ issues caught early
- Found issues in eight online services before users ran into them.
- 12+ urgent problems fixed
- Fixed problems that blocked client work, usually within 24 hours.
- 4 hours saved each week
- Automated more than 15 manual release steps.
Selected Work
A pharmacy learning platform, rental marketplace, civic health app, pricing tool, automata workspace, and job-search pipeline.
Open a case study to see the user problem, what I owned, the decisions behind the build, and the proof available from the repository.
- Live
- Custom Build
- Mobile App
HEALTH
Led a five-person team to the semi-finals, placing in the top 15 of 200+ teams at the 1st Naga City Mayoral Hackathon.
Live- Custom Build
- PWA
PriceCraft
Calculates ingredient, labor, and overhead costs using both markup and profit-margin pricing strategies.
About
Product delivery shaped by production operations.
My work spans client delivery and production monitoring. I turn requirements into explicit system states, keep trade-offs visible, document the handoff, and verify changes with tests and rollout checks.
Experience
Software Monitoring Engineer
—Present
Wind's Gate Philippines — Cebu City
- Identified and escalated 25+ incidents across eight production services before they reached end users.
- Authored eight recovery runbooks that enabled engineers to resolve Tier 1 issues without escalation and reduced average triage time by 30%.
Freelance Software Engineer
—Present
Upwork — Remote
- Resolved 12+ production-blocking defects with an average turnaround of less than 24 hours, restoring affected client workflows.
- Rebuilt release automation to remove 15+ manual steps and save approximately four engineering hours per week.
- Delivered three client-facing features using React, TypeScript, and Node.js and wrote REST API documentation that reduced contributor onboarding from one week to two days.
Software Engineer (Contract)
—
Pharmacy & Acute Care University — Remote
- Build and maintain full-stack features for an online learning platform, including admin workflows, personalized study programs, eBook and reader access, review reminders, and subscription-based access.
- Diagnose production issues involving React and TypeScript interfaces, Node.js APIs, PostgreSQL schemas and migrations, content assets, and entitlement rules; implement targeted fixes that restore blocked learner and administrator workflows.
- Contribute to technical design, code review, automated testing, rollout planning, and reliability improvements across frontend and backend systems.
Software Engineer Intern
—
Alliance Software Inc. — Cebu City
- Contributed to enterprise web applications using C# and ASP.NET MVC across frontend and backend tasks.
- Collaborated with senior engineers through code reviews, pair programming, and agile ceremonies.
Full-Stack Developer Intern
—
Bayoa Analytics — Remote
- Worked across Node.js and Express APIs and React interfaces for analytics-focused product workflows.
- Built reusable interface components with TypeScript and Tailwind CSS and contributed database and API performance improvements.
Core stack
The tools most relevant to the product, reliability, and automation work I take on.
Product development
- TypeScript
- React
- Next.js
- React Native
- Flutter
- Node.js
- Tailwind CSS
Backend and data
- REST APIs
- PostgreSQL
- Supabase
- Prisma ORM
- Drizzle ORM
- MySQL
- MongoDB
Delivery and automation
- Vitest
- GitHub Actions
- Docker
- Vercel
- n8n
- Groq API
- PayMongo
Certificates
GCI World April 2026 (opens in new tab)
Matsuo-Iwasawa Laboratory, The University of Tokyo
Education
Bachelor of Science in Computer Science
—Present
University of the Philippines
- University Scholar (consistent academic honor)
- Semi-Finalist, 1st Naga City Mayoral Hackathon
Bachelor of Science in Mathematics
—
University of the Philippines
- College Scholar (consistent academic honor)
- DOST Junior Level Science Scholarship (JLSS) Awardee
Contact
Need a full-stack feature shipped or a fragile workflow fixed?
Send the problem, your current stack, and the outcome or timeline you are working toward. I will reply within 48 hours with whether I can help and a practical next step.