Josiah Nunemaker

Founding Engineer & Frontend Tech Lead

Founding engineer and frontend tech lead with a proven track record building B2B and B2C applications at scale. My bread and butter is rich user interactions, ensuring the experience feels good to use, not just functional. I innovate on products while still keeping interfaces intuitive and easy to understand, bridging the gap between complexity and seamless UX.

Experience

Journalytic / Baserate

2022 — 2026

Founding Engineer & Frontend Tech Lead

B2C investment journaling platform (Journalytic) and B2B investment operating system (Baserate) built on a shared codebase.

  • First full-time engineer; grew from pre-launch to 10,000+ users across 50+ countries, including 40+ investment firms representing $50B+ AUM .
  • Built core product modules (Timeline, Idea Lists, Decisions, Dashboards) and key differentiator features including conviction scoring, sentiment and emotional marker tracking, idea-level dashboards with price chart overlays, and process analytics.
  • Reduced core feature load time by more than half by engineering a custom-built high-performance virtualized list powering 3 core surfaces, supporting mixed content, anchored scrolling, and infinite scroll.
  • Implemented complex virtualized data grids with thousands of rows based on Tanstack Table supporting custom properties (text, numbers, multi-select, people, multi-choice), filtering, sorting, and column configuration.
  • Built real-time SSE-based entity sync across workspace members delivering live updates for changed entity modifications across clients.
  • Led DX initiatives including frontend Firestore → Postgres migration for reliability and scalability, and JS → Rust frontend toolchain reducing dev server and build time and memory consumption by 30%+.
  • Built AI tooling and custom skills (including automated icon extraction from design mocks) that caught bugs before review, reduced reviewer burden, provided context on features, and supported automation.
  • Set early standards for code health (formatting, linting, review pipelines, ideas-to-implementation workflows) and participated in technical interviews for engineering hires.

ThirtyTech

2018 — 2022

Lead Developer

Multi-tenant member management SaaS for one of the top 10 US unions, with per-local customization.

  • Migrated ExtJS → React, including migrating to AG-Grid for virtualized data tables handling thousands of rows.
  • Built Stripe-based automated payment pipeline for dues and fee collection.
  • Maintained robust two-way sync system bridging legacy on-prem customer databases with modern cloud infrastructure.
  • Rewrote dev tooling, yielding 70+% reduction in compile time.

Reciprocal Ministries International

2015 — 2018

IT Services Technician

IT infrastructure for NGO in southern Haiti.

  • Managed IT infrastructure and automated administrative workflows (Google Apps Script).
  • Increased network throughput 8× by optimizing routing policies and hardware for 30+ employees.

Projects

For a more complete list, see josnun.com.

  • Dark mode Bible.com browser extension with 5k+ weekly active users (vanilla JS, CSS)
  • Inscribe, a community scripture-memorization app (Flutter, Bun, Postgres) with spaced-repetition reviews tuned to each user's mastery of the content
  • Display Reinitializer Raycast extension using native Swift APIs to query display info and reconnect misbehaving displays
  • Personal Homelab with a Proxmox hypervisor running Home Assistant, Caddy, CouchDB, WireGuard, Coolify, and other utilities

Skills

Stack
TypeScript, React, Tailwind, Tanstack, Postgres, Node.js, Go
Concepts
Data grids, virtualization, SSE, responsive design, AI agents, build tooling, MCP Apps
Tools
Git, Linear, Figma, Claude Code, shell, Sentry, LogRocket