● WL / Engineering & product developmentSan Mateo, California   +
WILLIAM LUBELSKIFRONTEND ENGINEERING

Products / Interfaces / Systems

William
Lubelski.

I build thoughtful products and the systems that make them easier to develop, maintain, and evolve.

Explore the work

FRONTEND ENGINEER / SYSTEMS THINKER
BASED IN SAN MATEO, CALIFORNIA

FIG. 01 / ENGINEERING PRACTICEWL–001
FROM THE INTERFACE
TO THE UNDERLYING SYSTEM.[ NOT TO SCALE ]
Current / Mercury
Senior Frontend Engineer
Product area
Spend Management
Core tools
TypeScript / React / CSS

01 / Experience

A record of building things

Products built.
Systems improved.

Product engineering, frontend architecture,
and helping other engineers do good work.

Mercury

SEP 2024 → PRESENT

Senior Frontend Engineer
Remote / SF Bay Area

Product engineer for Spend Management.

Rebuilt a legacy form library with TypeScript and React hooks, using advanced types to preserve backwards compatibility.

Toast

OCT 2022 → AUG 2024

Staff Frontend Engineer
Remote / SF Bay Area

Led a team to improve Shift Management search performance, reducing page load times for larger customers from multiple minutes to 500 ms.

Led the navigation and branding overhaul for the Payroll product.

Built frontend infrastructure for localization, wizard workflows, type-safe reactive localStorage, and client-side navigation alongside legacy server-rendered pages.

Carta

2021 → 2022

Senior Developer II, Frontend
Remote / SF Bay Area

Re-architected data fetching and the frontend of TotalComp.

Designed and built the frontend for the HRIS integration system.

Supported a junior engineer leading the Total Rewards frontend project; advocated for and adopted Carta’s micro-frontend system.

Peach Finance

JUL 2020 → MAY 2021

Senior Frontend Developer
Remote / SF Bay Area

Built the customer-facing payments and account management portal.

Designed a system to embed the customer portal in the admin portal for smoother support interactions.

Worklete

APR 2019 → FEB 2020

Senior Frontend Developer
San Francisco, CA

Led the transition from a white-label CMS prototype to an in-house web application, prioritizing simple, maintainable architecture.

Mentored junior engineers through pair programming and cross-team collaboration.

EverTrue

MAR 2015 → APR 2019

Frontend Developer
Boston, MA

Built features for data-rich CRM and nonprofit fundraising applications using React and Backbone.

Designed and built a Flux-based state management library, then helped transition the application to modern React practices.

Mentored junior frontend developers.

Earlier work /

Frontend development at Kitewheel (2014), UX at SoftArtisans (2011–2012), and mechanical engineering at Bicon Dental Implants (2008–2011, 2012–2014).

02 / Technical practice

Behind the interface.

A / Language

TypeScript & JavaScript

Type-safe APIs, recursive and mapped types, and backwards-compatible library design.

B / Architecture

React & systems

Hooks, state management, data fetching, performance, and legacy-system integration.

C / Interface

CSS & design

CSS-in-JS, styled-components, LESS, PostCSS, and vanilla CSS. A grounding in UX and human factors.

Foundations / Education

A systems-first
perspective.

From aerospace engineering and mathematics to human factors and product development.

University at Buffalo (SUNY)

B.S. Aerospace Engineering
B.A. Mathematics

Bentley University

Coursework in Human Factors in Information Design: user research, testing and assessment, and measuring user experience.

General Assembly

Product Management evening course / Boston, MA

03 / Contact

Let’s build something thoughtful.

will.lubelski@gmail.com ↗