Nicholas Maassen

Full-stack engineer building workflow-heavy software.

I work across product scoping, UI, backend, vendor APIs, infrastructure, and production hardening — shipping integration-heavy software for real users.

Roles Product Engineer · Implementation Engineer · Forward-Deployed Engineer

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Latest writing

Flip the hammer over

How I learned to write as little software as possible.

May 8, 2026

Recent work scheduling sync · ACH/payment workflows · AI-assisted care reports · CRM dashboards

Stack TypeScript · React · Cloudflare Workers/D1 · Postgres · Stripe · Microsoft Graph

Work

Client systems first: production workflows, integrations, payments, CRM sync, and AI-assisted operations. Public side projects follow as live demos with code.

Client systems

Scheduling sync for pregnancy centers

Client work · NDA-safe

Problem: Pregnancy centers needed appointment data synced between GoHighLevel/LifeLead and CoolFocus with reliable reconciliation.
Shipped: GoHighLevel/LifeLead to CoolFocus integration with reconciliation jobs, lifecycle mapping, encrypted credentials, admin setup flow, demo automation, and Sentry monitoring.
Result: Production deployment shipped and running.
Stack: Cloudflare Workers · D1 · Hono · React · Clerk · Sentry

B2B automotive marketplace

Client work · NDA-safe

Problem: B2B wholesale used-car transactions needed payment, title verification, and multi-tenant access control.
Shipped: ACH checkout, webhook-driven payment status, title-verification payout gate, purchase-order states, invitation flows, EIN validation, and RLS-backed permissions.
Result: Multi-tenant B2B wholesale transaction flow delivered.
Stack: React · Supabase · Stripe Connect · Postmark · FedEx

AI-assisted care workflow

Client work · NDA-safe

Problem: Care providers needed to turn booking and recording data into structured reports with role-based review.
Shipped: Booking-to-report pipeline: transcription, LLM-generated reports, prompt/eval tooling, and role-based review surfaces.
Result: Production auth and domain hardening for a healthcare context.
Stack: React · Bun · Microsoft Graph · Deepgram · OpenAI · Promptfoo

Financial-planning dashboard

Client work · NDA-safe

Problem: Financial advisors needed CRM-synced dashboard workflows with data review and validation.
Shipped: Dashboard and data-review workflows with Redtail CRM sync, sanitized local fixtures, staging/live data posture, validation, sync logs, and operational review UX.
Result: Advisor-facing review workflows with full reconciliation sync and validation.
Stack: React · Bun · Fastify · Drizzle · Postgres · Redtail CRM

Public tools

Cube Merge

Side project

Problem: Cube-building hobbyists needed to review and collaborate on changes without accounts or identity-based trust.
Shipped: Real-time review tool with immutable change log, anonymous branching from any prior point, six change types, threaded @-mention comments, virtualized rendering for 500+ cards, and CubeCobra-compatible export.
Result: Lighthouse 100/100 · 307 KB bundle.
Stack: TypeScript · React · Firestore · Cloudflare Pages

Live · Code

Trait Ranker

Side project

Problem: Ranking many traits by comparison is tedious; users need fewer decisions to reach a final order.
Shipped: Drag-and-drop pairwise ranking with heap-sort (top-7) then merge-sort (final order), social guessing loop, anonymous Firebase sessions, and exportable results.
Result: Lighthouse 99/100 · ~50 users.
Stack: TypeScript · React · Firebase

Live · Code