
Upwex
AI copilot for Upwork freelancers – proposal generation, lead scoring, CRM sync. Built from zero as CTO & co-founder.
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Web · Mobile · AI
Eight years turning ambitious specs into web apps, mobile apps and Chrome extensions that 10,000+ people use daily. Angular, React, React Native – from system architecture to the last easing curve.
Capabilities
full cycle – idea to store
Enterprise Angular & React systems that stay fast past 100k lines – dashboards, marketplaces, fintech backends for the frontend.
React Native for iOS & Android – one codebase, genuinely native feel, shipped to both stores and used by real teams every day.
Chrome extensions with AI under the hood – from architecture and store review to 10,000+ active users on Upwex alone.
The CTO playbook: system design, legacy rescue, code-review culture and mentoring for teams that want to move faster.
Services
what you can hire me for
$
Selected work
2017 → 2026

AI copilot for Upwork freelancers – proposal generation, lead scoring, CRM sync. Built from zero as CTO & co-founder.
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The meal-benefits platform feeding NYC's biggest teams. Frontend across the web platform and the React Native app.
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Fintech infrastructure – payments, KYC flows and operator dashboards for a global payment ecosystem.
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Web3 studio site with heavy motion design – built to prove a point about what the browser can do.
Visit site ↗Track record
2017 → today
About me
the human behind the commits
Eight years ago I wrote my first production Angular app; today I run engineering at Upwex, the AI copilot I co-founded for Upwork freelancers. In between: rescuing legacy codebases at scale, leading frontend teams, and shipping web and mobile products that 10,000+ people use every day.
My lane is the full frontend lifecycle – architecture, build, tests, performance, store review – plus enough Node.js (NestJS, MongoDB) to design the API I'm consuming. I care about the boring things that make products fast: typed contracts, measured performance and code the next engineer can read without me in the room.
Writing
notes from the trenches
FAQ
before you write
Yes – I take on a small number of projects alongside my CTO role at Upwex, which keeps the bar high for what I commit to. The best first step is a short email describing what you're building.
Three formats: project-based delivery with a written scope, a fractional tech-lead role (part-time, ongoing), or a focused architecture audit. Long-term contracts are possible when the product is interesting.
Central European time (Portugal). That gives full overlap with European teams and comfortable morning overlap with US East Coast. Async-first communication works best either way.
Yes – legacy rescue is a specialty. I've migrated large AngularJS platforms to modern Angular and untangled codebases past 100k lines. The process starts with a read-only audit week, then a prioritized plan before any rewrite talk.
It depends on the team you'll hire, not fashion. My defaults: Next.js or React for most web products, Angular for large enterprise teams that value convention, React Native when web and mobile share a domain, NestJS + MongoDB on the backend.
Both. I can ship a product end-to-end alone – architecture to store review – or embed into your existing team as a lead: reviews, mentoring, hiring loops and standards included.
Email sinclar96@gmail.com with two paragraphs: what you're building and what's blocking you. You'll get an honest reply – sometimes that's 'you don't need me yet' – and if it fits, a call and a written scope within a week.
Contact