Building software that solves real problems.
Building software that solves real problems.
I'm John Anthony Pecson — a senior product engineer with 10+ years taking software from an ambiguous idea to a production system across healthcare, fintech, SaaS, and AI. I've founded companies and led engineering teams, and I care as much about long-term reliability as I do about shipping the first version fast.
From ambiguous idea to reliable product.
The part I like isn't the code for its own sake, it's the moment a vague, half-formed idea starts turning into something real and dependable. Ten-plus years in, across healthcare, fintech, SaaS, and AI, that's still the work: product thinking first, then the architecture, the interface, and the thousand small decisions that make software feel obvious to use.
I've done it as a founder, a CTO, and a lead engineer, taking products from concept to production and keeping them alive afterward. Shipping fast matters, but so does the long-term work: distributed systems that hold up, clean boundaries, and code the next person, including future me, can actually maintain.
Products built from zero to scale.
When seconds matter, your team is ready.
My flagship product. A mission-critical healthcare communication platform that lets psychiatric facilities coordinate emergency response, staff communication, and operational workflows across Apple Watch, iPhone, iPad, and web, designed and built end to end.
The complete platform for pickleball.
An end-to-end booking marketplace for the Philippine market, court booking, tournaments, coaching, and venue management, built on a multi-tenant architecture with integrated GCash and Maya payments.
A social SaaS platform for crypto traders.
As Lead Full-Stack Developer & Product Engineer, I led the technical evolution of a production-scale crypto education and community platform, architecting the systems behind premium memberships, real-time engagement, and subscriptions.
Two of you. One does the boring part.
A cross-platform AI desktop companion focused on local-first automation, developer productivity, and privacy-preserving workflows, built to run entirely on your own machine.
A zero-knowledge secret manager for developers.
An open-source, zero-knowledge secret manager with a Go-based CLI and Model Context Protocol (MCP) integration for secure, AI-assisted development workflows, the server never sees your secrets. Proof that I build for developers, not just SaaS.
A decade of building & leading.
Led the technical evolution of a global crypto education platform, with a focus on high-concurrency architecture and real-time community engagement.
Engineered the identity and authentication layer for enterprise-grade workflow-automation tools.
Led engineering for a fintech startup, building a secure dispute-resolution engine for online transactions.
Architected backend services and integrated blockchain protocols for an international trading ecosystem.
Built decentralized applications and backend services for enterprise blockchain solutions.
Developed blockchain applications, SDK integrations, and developer tooling.
Developed healthcare and enterprise software across frontend, backend, and cloud infrastructure.
Developed mobile and web applications for international clients.
The full stack, end to end.
Notes from building in the open.
Open
SourceDesigning a zero-knowledge secret manager
How I architected MeowPass so the server can never read your secrets, Argon2id, AES-256-GCM, and X25519.
Cloud
Scaling WebSockets to 50K concurrent users
Connection sharding, backpressure, and the tricks that kept latency flat under bursty load.
Startups
From engineer to technical founder
The mindset shift behind taking products from zero to production, and owning the outcome.
Off the keyboard.
Father
Proud father of twins, my favorite long-term project.
Enduro Rider
Honda CRF150L · CRF125F · KLX140RF.
Mountain Biker
Transition Sentinel. Weekends are for descents.
Startup Builder
Always one venture deep. Twynn is the current one.
However you need to build, I'm in.
I love founding products, but I'm equally at home leading an engineering team full-time or building for businesses on commission. Three ways we can work:
Engineering leadership
Looking for a stable home where I can lead and ship, Founding Engineer, Head of Engineering, Staff / Principal, or Technical Lead. I bring architecture, product thinking, and zero-to-production execution.
Freelance & commissions
Available to design, architect, and build for other businesses, from a focused MVP to scaling an existing platform. Healthcare, fintech, marketplace, AI, and SaaS.
Co-founder & advisory
If you're building something meaningful and need a technical co-founder or a hands-on advisor, I love partnering from the earliest days, shaping product and architecture together.
Let's build something amazing together.
Hiring for a senior or leadership role, need a senior builder for a commissioned project, or looking for a technical co-founder? If you're building something that matters, let's talk.