WorkThe April wave
PebbleDesk
Ran attendance, staff-to-child ratios, billing, and state subsidy claims for licensed daycare centers, in real time, on tablets directors actually carried around the room.
- Ran on
- Cloudflare
- Ran
- April 2026 to June 2026
- Domain
- Childcare compliance
That platform choice is part of a longer migration: Azure, then Railway, then Cloudflare, across the whole estate. Read how and why.
Built with
- Cloudflare Workers
- Hono
- React 19
- Astro 5
- Neon Postgres
- Drizzle
- Better Auth
Hosted services
- Cloudflare Workers
- Hyperdrive
- Durable Objects
- D1
- Neon Postgres
The decision
A subsidy claim is a request for public money, and the rule is that claim periods for one subsidy
case must not overlap, or the same days of care get billed twice. That is wrong in a way testing
rarely catches. Under Postgres’s default READ COMMITTED, two concurrent requests for
adjacent-but-overlapping periods can both run their SELECT, both see zero conflicting rows, and
both INSERT. Neither can see the other’s uncommitted row, and there is no row to lock, because the
conflict is between a row that exists and a row that does not exist yet. SELECT ... FOR UPDATE
fails for the same reason: you cannot lock the absence of a row.
Three fixes were available: SERIALIZABLE isolation, an advisory lock on the subsidy case, or a
database constraint. The constraint won because it is the only one of the three that stays true no
matter how the row got written. A future migration script, a manual psql session, or a second
service would all be subject to it, and none of them would honour an advisory-lock convention they
had never heard of. Both subsidy claims and staff shifts ended up on EXCLUDE USING gist
constraints over a computed range: a daterange for claims, and a numrange over
minutes-since-midnight for shifts, whose bounds semantics differ. The API catches the resulting
23P01 and returns a clean 409.
The 2026-06-11 shutdown checked every Cloudflare resource type separately (Workers, Pages, R2, D1,
Hyperdrive, KV, queues, Email Routing), verified five hostnames directly against DNS, and named the
exact Neon project, branches, and computes it removed. The same checklist recorded which external
services it had confirmed and which were still open, so the shutdown left a record rather than an
assumption. The deploy scripts were rewritten to throw on invocation, with the wrangler.jsonc files replaced by a two-line decommission notice.
Architecture
Browser to Cloudflare Worker to Hyperdrive to Neon Postgres, with a Durable Object handling rate
limiting. Three apps (a React SPA, a Hono API, and an Astro marketing site) shared five internal
packages through a pnpm/Turborepo workspace, and every tenant-scoped table carried a center_id
enforced by composite foreign keys rather than application-level filtering alone.
The audit log recorded who changed what, when, and which fields changed, for every write against a tenant-scoped table.
By the numbers
Each figure carries where it came from and when it was measured. Open one to see the command behind it, where the repository recorded a command.
- Application source
- 88,514 lines across 551 files (non-test)
Provenance
Source portfolio/METRICS.md § Size
git ls-files | grep -E '\.(ts|tsx|astro)$' | grep -vE '\.test\.' | xargs wc -l | grep -E 'total$' | awk '{s+=$1} END {print s}'Measured
- Test code
- 168,704 lines across 480 test files (roughly 1.9:1 against source)
Provenance
Source portfolio/METRICS.md § Size
git ls-files | grep -E '\.test\.(ts|tsx)$' | xargs wc -l | grep -E 'total$' | awk '{s+=$1} END {print s}'Measured
- Test cases
- 7,818-case test suite
Provenance
Source portfolio/METRICS.md § Counting test cases
git ls-files | grep -E '\.test\.(ts|tsx)$' | xargs grep -hoE '(^|[[:space:];{}])it(\.(only|skip|todo|concurrent))?(\.each\([^)]*\))?\(' | wc -lMeasured
- Data model
- 44 tables over 68 migrations, with 2 GiST exclusion constraints
Provenance
Source portfolio/METRICS.md § Data model
grep -rhoE '= pgTable\(' packages/db/src/schema/ | wc -lMeasured
- API surface
- 34 API route modules; 40 files under apps/site/src/pages (31 marketing pages, 9 .ts data/API endpoints)
Provenance
Source portfolio/METRICS.md § Surface area
git ls-files 'apps/api/src/routes/*.ts' | grep -vE '\.test\.' | wc -lMeasured
- Compliance model
- 18 staff-to-child ratio rules (3 states x 6 age groups), each carrying its legal citation
Provenance
Source portfolio/METRICS.md § Compliance model
Measured
- History
- 1,443 commits, 2026-04-07 to 2026-07-08, 1 human contributor plus 39 commits from an agent account
Provenance
Source portfolio/METRICS.md § Source repository history
git rev-list --count HEADMeasured
Screens
Its portfolio/ directory holds the architecture, metrics and testing documents these figures were taken from.