Web applications · Vanilla JS, React, Postgres
Not a separate hobby from the learning work — the reason I can design an interaction that doesn’t exist in an authoring tool yet. These are deployed applications with real backends, row-level security, auth, and in a couple of cases actual users who noticed when something broke.
Philadelphia, PA petercelona.pm@gmail.com github.com/BeCuriousSTEAMLab
Pennsylvania law requires homeschooling families to have an annual evaluation by a qualified evaluator, and there was no good way to find one. A searchable directory across all 67 counties, with evaluator profiles and a moderated signup flow so listings are reviewed before they go public.
Built without a framework or build step, on Postgres with row-level security policies rather than trusting the client. I’m the first listed evaluator.
A World Cup 2026 prediction pool — scoring, standings, per-match locking, live results. Not a learning artifact, and it’s here for a different reason: it shipped against an immovable deadline, with people actively using it, which is a different discipline from building something no one is waiting for.
The scoring formula was the easy part. Handling a user who opens the app mid-match, on a phone, expecting the standings to already be right — that was the work.
Where the two halves meet. A K–8 mathematics learning system built on H. Wu’s definitions-first framework, with every interactive element written by hand because no authoring tool does what the instructional design requires.
The combination is the point — I can talk to engineering and design the training, which usually saves a handoff.
Peter Celona petercelona.pm@gmail.com Learning design work