The request

From Catherine Hale, Chief Executive Officer
Your goal
Step 1 of 4. Revenue block. Set result to a DataFrame with one row per month of 2025 (sorted) and columns month, orders (distinct booked orders), net_sales, refunds, net_revenue (net_sales − refunds), aov (net_sales / orders) and return_rate_pct (refunds × 100 / net_sales), money and rates rounded to 2.
- Use the
order_itemsDataFramenot done yet - Use the
returnsDataFramenot done yet - Show exactly
monthordersnet_salesrefundsnet_revenueaovreturn_rate_pctnot done yet
Step 2 of 4. Customer and traffic block. Set result to a DataFrame with one row per month of 2025 (sorted) and columns month, sessions (web sessions started that month), conversions (converted sessions), conversion_pct (conversions × 100 / sessions, rounded to 2) and new_customers (customers whose first booked order falls in that month).
- Use the
ordersDataFramenot done yet - Use the
web_sessionsDataFramenot done yet - Show exactly
monthsessionsconversionsconversion_pctnew_customersnot done yet
Step 3 of 4. Growth block. Using monthly from the starter, set result to a DataFrame with one row per month of 2025 (sorted) and columns month, net_revenue, net_revenue_ly (the same month of 2024), yoy_pct ((net_revenue / net_revenue_ly − 1) × 100) and orders_yoy_pct (the same for orders), all rounded to 2.
- Use the
ordersDataFramenot done yet - Use the
order_itemsDataFramenot done yet - Show exactly
monthnet_revenuenet_revenue_lyyoy_pctorders_yoy_pctnot done yet
Step 4 of 4. Guardrail check. The return-rate guardrail is 7%. A month is final once 40 days have passed after its last day, on or before 2025-12-31. Set result to a dict: "breaches", the sorted list of final 2025 months with return_rate_pct above 7, and "not_final", the sorted list of 2025 months that are not final yet.
- Use the
ordersDataFramenot done yet - Use the
order_itemsDataFramenot done yet - Store a dict in
resultnot done yet
Step 1 · your code
Loading the editor…
Reference solution
| order_item_id | order_id | product_id | quantity | unit_price |
|---|---|---|---|---|
| 1 | 1001 | 121 | 9 | 31.99 |
| 2 | 1001 | 154 | 3 | 11.99 |
| 3 | 1002 | 154 | 4 | 11.99 |
| 4 | 1002 | 194 | 1 | 149.00 |
Mote checks your result
Press Run. Each row that matches the goal becomes a firefly in your lantern.
Step 2 · your code
Loading the editor…
Reference solution
| order_id | customer_id | order_date | status | channel |
|---|---|---|---|---|
| 1001 | 125 | 2023-01-01 20:51:19 | completed | web |
| 1002 | 156 | 2023-01-02 07:58:46 | completed | web |
| 1003 | 22 | 2023-01-02 10:25:27 | completed | marketplace |
| 1004 | 48 | 2023-01-02 11:21:51 | completed | marketplace |
Mote checks your result
Press Run. Each row that matches the goal becomes a firefly in your lantern.
Step 3 · your code
Loading the editor…
Reference solution
| order_id | customer_id | order_date | status | channel |
|---|---|---|---|---|
| 1001 | 125 | 2023-01-01 20:51:19 | completed | web |
| 1002 | 156 | 2023-01-02 07:58:46 | completed | web |
| 1003 | 22 | 2023-01-02 10:25:27 | completed | marketplace |
| 1004 | 48 | 2023-01-02 11:21:51 | completed | marketplace |
Mote checks your result
Press Run. Each row that matches the goal becomes a firefly in your lantern.
Step 4 · your code
Loading the editor…
Reference solution
| order_id | customer_id | order_date | status | channel |
|---|---|---|---|---|
| 1001 | 125 | 2023-01-01 20:51:19 | completed | web |
| 1002 | 156 | 2023-01-02 07:58:46 | completed | web |
| 1003 | 22 | 2023-01-02 10:25:27 | completed | marketplace |
| 1004 | 48 | 2023-01-02 11:21:51 | completed | marketplace |
Mote checks your result
Press Run. Each row that matches the goal becomes a firefly in your lantern.
What Catherine gets, and why
DataFrames
Loaded for you as pandas DataFrames, plus pd and np.
order_items30,338 rows · 6 columns
order_item_idintegerorder_idintegerproduct_idintegerquantityintegerunit_pricedecimaldiscount_pctdecimal
| order_item_id | order_id | product_id | quantity | unit_price | discount_pct |
|---|---|---|---|---|---|
| 1 | 1001 | 121 | 9 | 31.99 | 0.00 |
| 2 | 1001 | 154 | 3 | 11.99 | 0.00 |
| 3 | 1002 | 154 | 4 | 11.99 | 0.00 |
| 4 | 1002 | 194 | 1 | 149.00 | 0.00 |
| 5 | 1002 | 193 | 2 | 19.99 | 0.00 |
returns1,673 rows · 5 columns
return_idintegerorder_item_idintegerreturned_ondatereasonvarcharrefund_amountdecimal
| return_id | order_item_id | returned_on | reason | refund_amount |
|---|---|---|---|---|
| 1 | 14 | 2023-01-10 | damaged | 83.69 |
| 2 | 42 | 2023-01-10 | wrong_item | 19.99 |
| 3 | 105 | 2023-01-14 | wrong_item | 10.99 |
| 4 | 24 | 2023-01-16 | changed_mind | 26.99 |
| 5 | 126 | 2023-01-16 | late | 20.99 |
orders12,000 rows · 7 columns
order_idintegercustomer_idintegerorder_datetimestampstatusvarcharchannelvarcharshipping_feedecimalcoupon_codevarchar
| order_id | customer_id | order_date | status | channel | shipping_fee | coupon_code |
|---|---|---|---|---|---|---|
| 1001 | 125 | 2023-01-01 20:51:19 | completed | web | 0.00 | NaN |
| 1002 | 156 | 2023-01-02 07:58:46 | completed | web | 0.00 | NaN |
| 1003 | 22 | 2023-01-02 10:25:27 | completed | marketplace | 4.99 | WELCOME10 |
| 1004 | 48 | 2023-01-02 11:21:51 | completed | marketplace | 4.99 | WELCOME10 |
| 1005 | 82 | 2023-01-02 11:43:36 | completed | web | 0.00 | WELCOME10 |
web_sessions40,000 rows · 7 columns
session_idintegercustomer_idintegerstarted_attimestampdevicevarcharsourcevarcharpages_viewedintegerconvertedboolean
| session_id | customer_id | started_at | device | source | pages_viewed | converted |
|---|---|---|---|---|---|---|
| 1 | NaN | 2023-01-01 23:02:24 | mobile | paid | 1 | false |
| 2 | 18 | 2023-01-01 15:07:49 | desktop | paid | 1 | false |
| 3 | NaN | 2023-01-01 16:55:46 | desktop | direct | 7 | false |
| 4 | NaN | 2023-01-01 12:43:28 | mobile | organic | 3 | false |
| 5 | NaN | 2023-01-01 13:06:21 | mobile | social | 2 | false |
customers2,018 rows · 9 columns
customer_idintegerfirst_namevarcharlast_namevarcharemailvarcharcityvarcharstatevarcharsignup_datedatesegmentvarcharreferral_sourcevarchar
| customer_id | first_name | last_name | city | state | signup_date | segment | referral_source | |
|---|---|---|---|---|---|---|---|---|
| 1 | Owen | Hudson | owen.hudson@icloud.com | San Francisco | CA | 2022-06-02 | consumer | search |
| 2 | Douglas | Mendoza | dmendoza69@gmail.com | Atlanta | GA | 2022-06-02 | consumer | NaN |
| 3 | Henry | Brooks | hbrooks@lakesidecafe.com | Los Angeles | CA | 2022-06-04 | business | NaN |
| 4 | Brian | Graham | bgraham@bluecedarhomes.com | Seattle | WA | 2022-06-06 | business | |
| 5 | Kyle | Jimenez | kjimenez27@yahoo.com | Indianapolis | IN | 2022-06-07 | consumer | NaN |
products120 rows · 8 columns
product_idintegernamevarcharcategoryvarcharsubcategoryvarcharunit_pricedecimalunit_costdecimallaunched_ondateis_activeboolean
| product_id | name | category | subcategory | unit_price | unit_cost | launched_on | is_active |
|---|---|---|---|---|---|---|---|
| 101 | Vale Velvet Loveseat | Furniture | Sofas | 1659.00 | NaN | 2023-09-11 | true |
| 102 | Alder Oak Coffee Table | Furniture | Tables | 919.00 | 503.50 | 2024-05-16 | true |
| 103 | Orchard Rattan Dining Chair | Furniture | Chairs | 789.00 | 429.87 | 2023-05-27 | true |
| 104 | Upland Oak Bookcase | Furniture | Storage | 429.00 | 214.70 | 2022-12-20 | true |
| 105 | Avery Leather Bed Frame | Furniture | Beds | 449.00 | 232.70 | 2021-08-31 | true |
employees60 rows · 8 columns
employee_idintegerfirst_namevarcharlast_namevarchardepartmentvarchartitlevarcharmanager_idintegerhire_datedatesalaryinteger
| employee_id | first_name | last_name | department | title | manager_id | hire_date | salary |
|---|---|---|---|---|---|---|---|
| 1 | Catherine | Hale | Executive | Chief Executive Officer | NaN | 2016-03-01 | 285000 |
| 2 | Robert | Kim | Executive | Chief Operating Officer | 1 | 2017-01-09 | 235000 |
| 3 | Megan | Collins | Sales | Head of Sales | 1 | 2018-04-16 | 172000 |
| 4 | Chloe | Gutierrez | Sales | Account Executive | 3 | 2020-01-21 | 72000 |
| 5 | Frank | Bell | Sales | Account Executive | 3 | 2023-05-21 | 73000 |
marketing_spend3,276 rows · 3 columns
spend_datedatechannelvarcharamountdecimal
| spend_date | channel | amount |
|---|---|---|
| 2023-01-01 | paid | 492.99 |
| 2023-01-01 | 37.38 | |
| 2023-01-01 | social | 200.53 |
| 2023-01-02 | paid | 709.13 |
| 2023-01-02 | 64.13 |
The lesson
A KPI sheet is a page, not a dashboard
A KPI sheet is the one page a leadership team reads every month. It is short on purpose: the north star, the few numbers that drive it, growth against the same period last year, and the guardrails with a status. Everything on it has a written definition, and the definitions do not change between editions.
Harbor & Pine’s sheet has four blocks, and you build one per step.
Block 1: revenue
Orders, net sales, refunds, net revenue (the north star), AOV and the return rate, one row per month. All of it comes from one table of booked, valid lines with the refund attached, so the numbers add up across columns: net revenue is net sales minus refunds, and AOV × orders gives net sales back.
Block 2: customers and traffic
Sessions, conversions, conversion rate and new customers. These are the drivers: revenue grows because more people visit, more of them buy, or more of them are new. The conversion rate is conversions over sessions in the same month, computed from the totals.
Block 3: growth against last year
Harbor & Pine is seasonal, so the growth column is year over year, not month over month. Put orders growth next to revenue growth: when orders grow and revenue does not, orders got smaller, and that deserves a sentence on the sheet.
Block 4: guardrails with a maturity rule
The return-rate guardrail is 7% of net sales. A month can only breach it once its returns are in, which takes up to 40 days after the month ends. Months younger than that are listed as not final instead of being judged early, so the newest months cannot look better than they are.
Common mistakes
- Averaging monthly rates for the year. Recompute annual rates from summed totals.
- Month-over-month growth in a seasonal business. It measures the calendar.
- Judging young months. Delayed metrics need a “final from” date.
- Changing a definition between editions. If it must change, restate the history with it.
Lantern lit!
Practised: kpi sheetnet revenueaovreturn rateconversion rateyoyguardrail metricsdata maturity
- Solved
- No hints
- First run
