When I Work: Scalable Payroll & Technical Planning
Leading attendance and payroll architecture in React and Go, solving complex multi-timezone and overtime domain rules, and establishing proactive technical planning standards.
At a Glance
When I Work serves hundreds of thousands of shift workers and managers across multiple timezones, computing hourly attendance into accurate, compliance-grade payroll outputs.
Payroll calculation is unforgiving: an hour shift during Daylight Saving Time transition or miscalculating a blended overtime rate across multiple job roles directly affects employee wages and employer legal compliance.
Spearheaded technical development plans defining strict database access patterns, API contracts, and defensive boundary tests. Implemented robust calculation rules in Go and intuitive calculation verification interfaces in React.
Delivered zero-error payroll calculation runs, introduced React Testing Library across the team to eliminate manual regression passes, and mentored engineers through thorough architectural reviews.
Context
At When I Work, I spent four years progressing from Full Stack Developer to Senior Full Stack Developer on Attendance & Payroll. The work was converting punch events—clock-ins, breaks, job switches—into legally compliant pay period summaries using React on the frontend and Go / PHP on the backend.
The Problem
Payroll has no tolerance for ambiguous math. Small timezone or overtime mistakes become labor-law issues and wrong paychecks. The hardest constraints:
Multi-Timezone & DST
Overnight shifts crossing DST transitions had to preserve correct elapsed hours without double-counting or under-paying.
Blended Overtime Rates
Employees working multiple positions at different wages needed weighted overtime premiums, not a flat multiplier.
What I Built
Timezone-resilient pay calculations
Punch timestamps were stored in UTC and projected into the workplace IANA timezone only when partitioning calendar days. DST handling used elapsed wall-clock duration so an overnight shift during a fall-back transition correctly accounted for the extra hour worked.
FLSA blended overtime
For multi-position employees, I implemented the FLSA regular-rate calculation: total straight-time earnings ÷ total hours, then overtime premium of 0.5 × regular rate × overtime hours. Money math used fixed-point integers to avoid floating-point drift.
Development planning & frontend reliability
Development Plan Standard
Team PracticeScope boundaries before implementation starts.
Contracts, query patterns, and indexing considerations.
Timezone boundaries, failure modes, and feature-flag exits.
I also led the frontend testing migration from Enzyme snapshots to React Testing Library, with reusable fixtures and guidelines focused on real user interactions and accessible queries.
Outcome
- Reliable payroll math across multi-timezone attendance records and blended overtime rules.
- Development plans adopted across squads, reducing mid-sprint surprises on complex features.
- Stronger frontend regression safety after RTL adoption—and promotion to Senior Full Stack Developer.
Interested in discussing this architecture?
I'm currently open to Senior Frontend, Product Engineering, and Tech Lead opportunities. Let's talk about technical planning, high-concurrency systems, or frontend craftsmanship.