Designs by Duhart ← All infographics

Designs by Duhart · measured, not estimated

The numbers

Every figure below came from a file census or a written report — never an estimate. Vendored trees, virtualenvs, node_modules and generated protobuf output are excluded, because counting them is the easiest way to make a portfolio dishonest.

~4.3Mlines authored across /srv
28projects inventoried
13origin services
10edge Workers
4datastore families
24protobuf contracts
153test files, 3 languages
3client platforms
120commits on this branch
54manual chapters written

Backend services by authored lines

Single hue, more-is-darker in light and more-is-lighter in dark — magnitude only. Hover or focus a row for what it talks to.

Gateway trioapp/gateways
48,582
MatchServiceapp/MatchService
33,638
OpenHouseGlobalapp/OpenHouseGlobal
29,453
GlobalChatServiceapp/GlobalChatService
26,176
billboard-usersapp/workers/billboard_users
10,581
GlobalCloudflareAdapterapp/GlobalCloudflareAdapter
7,855
Solomon retrievalSolomon/retrieval
4,757
BillboardActivityServiceapp/BillboardActivityService
977
Table view
ServiceLanguageLines
Gateway trioGo48,582
MatchServiceGo33,638
OpenHouseGlobalTypeScript29,453
GlobalChatServiceGo26,176
billboard-usersTypeScript10,581
GlobalCloudflareAdapterGo7,855
Solomon retrievalGo4,757
BillboardActivityServiceGo977
The smallest bar is the highest-ranked project.

BillboardActivityService is 977 lines — the shortest service in this chart — and it sits at the top of the portfolio ranking. Line count measures effort, not leverage. A chart of size is a chart of size; it is not a chart of what will get you hired, which is why it appears here and not on the ranking page.

iOS product modes by lines of Swift

611,426 authored lines across 1,200 files, excluding Pods, frameworks and dependencies.

Dating
90,161
Array
90,017
Billboard
57,669
Main
37,714
BoxOffice
20,407
Universal
17,530
Global
17,246
OpenHouse
9,294
Identity
8,051
Registration
6,072
Table view — all 13 modes
ModeFilesLines
Dating14790,161
Array12290,017
Billboard12857,669
Main16037,714
BoxOffice4520,407
Universal2617,530
Global11017,246
OpenHouse579,294
Identity518,051
Registration136,072
Vitals142,582
Login51,427
Storefront5820

Verification surface

Tests, gates and measured results — the figures that are worth more than line counts.

153 test files

56 Go (*_test.go), 39 Python, 58 TypeScript — spanning race tests, benchmarks, contract-coverage tests and live end-to-end runs.

9 / 9 eval gates

Solomon's promotion pipeline. Two of the nine are latency and throughput, so "good enough" is defined on both axes before anything reaches a cluster.

86 % coverage

Solomon Python, 62/62 passing — including a causal-mask leak test and an overfit-one-batch test.

198 reqs · 0 failures

Load test against the inference service: p95 2.7 s against a 6 s SLO, HPA scaling to 3 replicas.

952 pending entries

The size of the Redis consumer-group PEL leak at the moment it was found in feed_index:writes.

14 / 52 parity

Measured feature parity against Spotify, written before any remediation began.

49 findings

F-01F-49 in the Dating audit, each with file:line, severity and evidence.

6 CI gates

Typecheck, unit, real end-to-end, contract diff, shadow types, secret detection — one of them added because of a specific past defect.

Datastores in production use

Cassandra 4.1.3

Chat history, match cards partitioned by (service_region, geohash4), feed timeline, OpenHouse. Schema migrates on boot.

Kafka

The activity log (6 partitions, keyed by actor), gateway event transport, Solomon retrieval ingestion.

Redis + Streams

Presence, sessions, and a feed index using consumer groups — where the PEL leak lived.

PostgreSQL

The transactional outbox, notifications, profiles. Reached from the edge through Hyperdrive.

Cloudflare D1

Edge-local relational storage for library and user data.

Cloudflare R2

Audio and video objects, multipart ingest, HTTP range streaming.

Durable Objects

IngestDO for single-writer upload sessions; JamzFingerprintDO running an FFT compiled to WASM.

S3 · KV

Chat media on S3; configuration and hot lookups on KV — never anything that must stay ordered.