SaaS MRR Dashboard.

Build an MRR dashboard for the finance lead at Cairnstack, a fictional B2B workflow analytics SaaS with about 400 customers on three plans: Starter at $49, Growth at $199, and Scale at $599, billed monthly or annually. Layout, top to bottom. A header row with two filters that recompute every number on the page: Plan (All, Starter, Growth, Scale) and Billing interval (All, Monthly, Annual), both defaulting to All. Below it, four stat cards: Current MRR (about $82,400), Net new MRR this month (about +$310), Expansion MRR this month (about $3,900), Churned MRR this month (about $2,750). Next, the centerpiece: a monthly MRR waterfall bar chart with a month selector covering the last 24 months, showing starting MRR, then new, expansion, and reactivation as upward bars, contraction and churn as downward bars, and ending MRR. Below it, a 24 month composed chart: grouped bars for the five movement types per month with a line for total MRR overlaid. At the bottom, a customer movements table for the selected month: customer, movement type as a colored badge, plan, billing interval, MRR change, and date, sorted newest first and sortable on every column. Clicking a waterfall bar filters the table to that movement type. Data to seed: a starting MRR baseline from 24 months ago totaling $61,000, broken down by plan and billing interval (six combinations that sum to $61,000) so the header filters recompute the waterfall's starting point too, plus about 180 customer movement records spread over the last 24 months. Each record has a realistic fictional company name (like Harbor and Finch, Ottermill Logistics, Beacon Supply Co), a date, a movement type (new, expansion, contraction, churn, or reactivation), plan, interval, and an MRR change between $49 and $1,200. Every movement type must appear in every recent month. Plant this story: through the first 18 months new business drives growth, but over the last 6 months new MRR flattens while expansion keeps climbing, and in the most recent 2 months churn plus contraction nearly cancel new business, so the waterfall shows growth visibly carried by expansion alone. Behavior: all totals, the waterfall, and the trend chart compute from the movement records and baseline, filtered by the header controls. A member only Log movement button opens a dialog capturing customer, type, plan, interval, amount, and date; the page must read perfectly for visitors who never open it. Color code movements: green for new and reactivation, blue for expansion, amber for contraction, red for churn. Visual identity: a deep blue accent on a clean white base, used for primary actions, active filters, the total MRR line, and chart emphasis.