Freelance Design Engineer

About the role

Mass Culture is a growth media agency that helps mission‑driven scale‑ups connect brand and performance so they grow faster, more profitably, and with purpose. As a paid media agency and growth partner, we build and run our own client portal where clients view media plans, budget pacing, cross‑channel performance, and reports. We are seeking a part‑time engineer to build features end‑to‑end and ensure they look as good as they work.

Our stack includes Next.js 16 (App Router), React 19, TypeScript, Supabase (Postgres, Auth, row‑level security, BigQuery), Tailwind CSS v4, Radix UI, a token‑based design system, visx for charts, Tiptap and dnd‑kit for editors and interaction, Zustand for state management, and tooling with bun and Vercel.

We work asynchronously and autonomously: you pick up scoped work, build it in a branch, open a pull request, we review and merge. Specs, design docs, and house conventions live in the repo; we expect you to verify your own work by opening the page and assessing what you see. Judgment, not typing, is the job.

Responsibilities

• Client‑facing surfaces: dashboards, widgets, charts, and report and deck builders.
• Admin surfaces: widget builder, plan editor, pacing tools, and configuration panels.
• Data plumbing: Postgres schema and migrations, server actions, and connector work against ad‑platform APIs.
• Polish passes on existing surfaces to improve finish and feel.

Requirements

• Strong React and TypeScript with real Next.js App Router experience (server components, server actions, caching behavior).
• Comfort with SQL and relational data modeling; able to write migrations and reason about what a query is actually doing.
• Portfolio or repo showing work you designed as well as built; a few well‑made pieces outweigh a long list.
• Ability to work independently in an unfamiliar, opinionated codebase and match its conventions.
• Clear written communication; most collaboration is text.
• Reliable part‑time availability; consistency matters more than volume.

Skills

• Data visualization experience, especially charts built on real, messy data.
• Experience with Supabase or Postgres row‑level security.
• Background in analytics, reporting, or BI‑style products.
• Comfort with design tools (mockups not required).
• Good eye for design: ability to take a rough spec and produce a considered surface, work within the design system, notice spacing, alignment, and type hierarchy, make charts readable, and distinguish between a surface that is merely working and one that is truly done.

Schedule

• Part‑time, freelance, remote, ongoing.
• Hours and rate are flexible and agreed up front.
• We start with a small paid scoped project to assess fit before committing to more.