CampaignsBots — Email Marketing Platform

CampaignsBots lets marketing teams design, schedule, and send email campaigns to segmented subscriber lists, with drip/trigger automation and detailed delivery analytics.

I built the campaign queue architecture, a GrapesJS-based drag-and-drop email template editor, subscriber import/export with deduplication, and a trigger/drip automation engine that fires based on subscriber behavior (opens, clicks, tags).

The original sending system used blocking sleep() calls for rate pacing, which caused queue starvation under load — a single slow campaign could block every other campaign in the queue. I replaced it with an atomic Redis fixed-window rate limiter trait, which let campaigns interleave fairly regardless of send volume.

Also resolved a job-flow collapse bug where two distinct queued jobs were being merged into one due to a shared job-signature collision, and fixed a cross-browser Safari rendering bug in the campaign builder caused by vendor CSS specificity conflicts with Select2.