Leaderboard & Counting Service  ·  View 03 of 21  ·  People and journeys

Actors and Their Core Journeys

Nine actors, three of them machines, and the goals they would state in their own words.

Editable source SVG draw.io All views
The people the numbers are about Product member 80M monthly Goal — Show me where I stand, and make my own effort count the instant I make it — if the number ignores what I just did, I stop believing all of it. Core journeys Check where I stand Watch a live round Top-ranked member the visible head Goal — Keep the ranking honest. If someone above me got there by exploiting a bug, I want them gone and the list corrected, not quietly patched. Core journeys Report a suspect rank The teams that ship the surfaces Product engineer 25 tenant teams Goal — Let me launch a new leaderboard this week by declaring it, not by learning how sorted sets shard. Core journeys Ship a new leaderboard Change a window definition Product owner owns the surface Goal — Tell me what the number means and how stale it may be, so the screen can say "as of" instead of implying it is live. Core journeys Agree a freshness budget The people who defend it Trust & safety analyst 24/7 rota Goal — When an exploit is running, let me stop the visible list and take the contributions out without deleting the evidence I need to prove it. Core journeys Remove a cheater Platform engineer 9 people Goal — Absorb one key taking a thousand times the median write rate without the other 3.5 billion counters paying for it. Core journeys Split a hot key Rebuild a projection Machines in the cast Product backend 250k events/s Goal — Hand off the event in under 25 ms and never be blocked by someone else's leaderboard being rebuilt. Core journeys Emit a batch of events Season closer weekly, per tenant Goal — Freeze last week's standings exactly once, without stopping this week's counting. Core journeys Close a season Reward service pays on standings Goal — Read a standing I can rely on not to change after I have paid out against it. Core journeys Grant on a closed standing Leaderboard & Counting Service — Actors and Their Core Journeys Person or role Journey / task External / third party Security / platform Three journeys get their own map: the member checking their standing, the engineer launching a leaderboard, and the analyst removing a cheater. They fail in three different places. v 1.0 · owner Platform Architecture · date 2026-10

What this view settles

  • The member's goal names the requirement the rest of the set exists to meet: if the number ignores what they just did, they stop believing all of it. That is read-your-writes stated by the person who needs it.
  • The trust & safety analyst is in the cast from the start. A leaderboard with a visible reward is a target, and retraction designed in later becomes mutation of live counters.
  • The season closer and the reward service are actors because the handover between them is where immutability stops being a nice property and becomes a payment.

Three journeys get their own map

  • The member checking where they stand — the loop that decides whether the platform is believed.
  • The engineer shipping a leaderboard — the loop that decides whether it is adopted.
  • The analyst removing a cheater — the loop that decides whether it is trusted after an exploit.

Assumptions

  • 25 tenant teams, 9 platform engineers, a 24/7 trust & safety rota.
  • A member opens a product surface carrying a leaderboard roughly four times a day.