16. Balancing

Every formula and tunable constant is here, with the checks that hold balance in place.

Source of truth. The build is normative: every number below is checked against the catalog in packages/simulation/src/catalog at the build this page ships with. Live tuning names the knobs and why they sit where they do, and What the checks cover says what each automated check asserts. Numbers measured from the build are in Measurements.

Number ranges#

Upload Labs players lose interest when numbers become meaningless (Influences). Quorum keeps every number in a real range.

Cash, revenue, and Burn are game dollars. Valuation, payout, and Legacy use real dollars, converted by the valuation scale.

Formatting: SI suffixes only (k, M, B, T). No letter suffixes such as "aa".

Constants#

The rollout steps and the certificate's two lifetimes are 05's own. A mesh takes a Cluster's half an engineer of Platform Dev Hours. The pages that own each mechanic give the rate it runs at.

Four rows describe the Features lifecycle: adoption time, lift spread, the upkeep ceiling, and the market gain cap. Adoption time is exact arithmetic, stepped a Step at a time, so the 63% after a week is the continuous curve's figure rather than a closed form. The market gain cap holds the Features' market gains together at +100% of the Era's market.

Prices#

The 1.25 growth on copies is a soft push toward bigger instances and toward better design over more copies. It is stylized, because real clouds charge the same for the hundredth VM as the first. The justification is operational overhead, and the card says so. Selling refunds half of what the last copy cost, at the copy markup.

Cost index#

Request values stay fixed. Prices rise with the Era. Every price in this document is a Garage price, and the Era's cost index multiplies it: placement, Burn, egress, and third-party fees. A separate salary index multiplies engineer salary. Without them, a vCPU costs about 0.1% of the value of the requests it serves, and Burn never matters.

Garage and Pre-seed sit at the floor because there the smallest box, not the traffic, sets the cost. From Seed the index climbs by 4 points an Era, so infrastructure and payroll grow with the company while request values stay put. Salary follows the index, and the language factor multiplies on top of it: PHP 0.85, Node.js and C# 1.0, Python and Java 1.05, Ruby 1.1, Go 1.15, Elixir 1.2, Rust and Zig 1.25, Haskell 1.4 (Runtimes). Live tuning records how far these values sit from the design's.

A Balanced design should land at a margin of 25% to 45%, which puts the Rule of 40 checklist item within reach but not free. pacing.test.ts records the margin at Seed and Series A entry.

Valuation scale#

Game revenue is stylized: 50 million users at 0.02 rps send 1 million rps, and the average request is worth about $1 to $3. A year of that revenue is about $500 billion. A real company of that size reports an ARR near $77 million. The valuation scale, 1.5 × 10⁻⁴, converts a year of game revenue into that real ARR. At the IPO, a Rule of 40 multiple of 13 gives a Valuation of about $1 billion. At 6 billion users the Valuation is about $100 billion.

Vertical and horizontal#

A size step doubles vCPU, RAM, and Burn. Price is linear in resources, as in real clouds, so price per vCPU does not decide between one big box and many small ones. These tradeoffs do:

Flat Components have size steps of their own, and each step doubles both capacity and Burn: Payments 6, Analytics 8, Load Balancer 6, Connection Pooler 4, Cache 8, Search Engine 8, Queue 6, WAF 6, Payment Provider 8, GPU Node 8, LLM API 8, Wide-column Store 6, Distributed SQL 6, Document Store 8, Event Stream 6, Realtime Hub 8, and Vector Index 6.

User growth#

The times solve the logistic equation from the Era's start to its milestone with the market sizes in Progression: t = ln(((M − U₀) / U₀) × (U₁ / (M − U₁))) / g. The sum is about 7 hours 36 minutes.

From Series C the formula runs per region (Simulation). With seed_share at 0.05, a Company that reaches Series C with 1,000,000 users starts Europe at 37,500, Asia-Pacific at 25,000, and South America at 12,500. Far demand is then about 7% of the total, not 60%, so a single-region Design meets the round trip as a warning, not as a collapse. North America's market alone is 5.6 million, so the 10 million Milestone needs users abroad. The table above assumes one region and the Era's full market.

Churn is steep on purpose, and much steeper than in real life. Brutlag (2009) found that 400 ms of extra latency cost Google 0.59% of searches over six weeks; the game compresses weeks into minutes. Fickle users carry the steepness: at the Series C target of 0.92, an Apdex of 0.91 loses them at about 3% per calendar hour. Steady users leave at a fifth of that. Three calendar days at 0.909 take a region of 1,000,000 users, half of them steady, to about 360,000, not 93,000 as with one rate. The Churn breakdown shows the rate.

Word of mouth crosses borders at m = 0.1. With 1,000,000 users at home, a region abroad grows as if it had 100,000 users of its own on top of its seed, so it fills fast once its users are served well, and it recovers after it lost its users.

Brutlag also found that searches stayed low for a while after the delay was removed. The game does not model that lag: users respond to the last calendar hour only, so a fix shows its effect within the hour. A lag would hide the feedback the Churn breakdown exists to give.

These are lower bounds. Capacity, Cash, and research make a real player slower, while Features raise g and the market, which makes growth faster still.

Growth alone sets the length of the first two Eras. At g × 1 the Garage takes 12 sim minutes to go from 150 to 1,000 users and Pre-seed 21 more to 5,000, so Seed arrives at about 33 sim minutes whatever the Design does. At the Company pace, where g is doubled, the same growth takes half as long.

Pacing model#

The pacing model is a set of scripted players that run against the real simulation in tests, so a balance change shows up as a test failure rather than in a playtest report. Every bot leaves the Team's autopilot on, and every bot but Greedy hires while payroll, the new hire included, stays under 25% of revenue, up to 4 engineers.

A balance change passes when the bots meet their limits on seeds 1–5: Balanced runs on all five seeds, the others on seeds 1–3 (pacing.test.ts and bots.test.ts, both under SLOW_TESTS=1).

Dominance#

Pillar 2 says no option strictly dominates another. dominance.test.ts runs in every pnpm test and in CI. Within each language, every runtime must beat each of its siblings by at least 10% on one reference score: throughput on the real Ledger of a Pre-seed Design, RAM per process, realtime connections per GB, startup, cold speed, stall-free CPU work, GC pause, leak-proof processes, a self-sized pool, or one of the six axes of its profile. Across languages, BEAM holds the most realtime connections per GB, beating Go and Kestrel. The option sets are the 28 runtimes, each language's frameworks, the instance families (Burstable, General, Compute, Memory), and the PHP-FPM pool modes. Axum and Actix are within about 5% of each other on CPU and velocity, and ARM runs at 0.8× the price and 0.95× the CPU, so a CPU-millisecond on ARM costs 0.84× General's. The fix for a dominated option is to change the option, not to tweak a number.

Runtime balance targets#

balance.test.ts asserts these comparisons on the real Ledger of a Pre-seed Design:

Under a PHP-FPM Design with OPcache, Node.js cluster mode answers read at 1.5× to 2.5× the throughput per dollar, and 3× to 6× with a database at 100 ms; a single Node.js process with 5% login adds 40 to 120 ms to p99.

Prestige curve#

The twelve perks of the Legacy shop cost 1,563 ★ in all. The cumulative column follows payouts of $500 million, $1.5, $5, $10, $20, $30, $40, $50, $80, $120, $160, and $200 billion for companies 1 to 12, so the shop is complete around the tenth company.

Payout is Equity × Valuation × the Exit's multiplier, so the rounds set it (Economy): 10% at 1,000 users, 19% at 5,000 and 25,000, 13% at 150,000, 12% at 1,000,000 and 10,000,000, and 15% sold in the IPO offering.

Live tuning#

The pacing knobs live in catalog/tuning.ts, and the cost and salary indexes in each Era (EraDef.costIndex and EraDef.salaryIndex). Two tunings read them:

• A Company plays at LIVE_TUNING: growth × 2, an incident every 200 sim seconds, and the first 90 seconds after the Pre-seed raise.

• A Challenge and a Sandbox replay at CHALLENGE_TUNING: growth × 1, an incident every 720 seconds, and the first after 600. The pacing bots use it too, so a run shows a whole curve inside a test.

Both share the calendar pace, so a calendar day lasts 60 sim seconds. The tuning parameter of step, growthOf, directIncidents, raise, and decline selects one.

The cost index, the salary index, and the speeds are one value each, set per Era or per perk rather than per tuning:

What the checks cover#

• pacing.test.ts, bots.test.ts and legacy-pacing.test.ts play the bots against the real Simulation; the slower ones run under SLOW_TESTS=1 and CI does not set it.

• balance.test.ts asserts the runtime targets above and runs in pnpm test.

• digests.test.ts and breadth.test.ts assert determinism, finite numbers and save round trips across the whole catalog.

• The bridge and the shutdown fire at the numbers in Economy; no bot plays a Company into a shortfall.