Complete Work Inventory, Ranked
J. Michael Duhart · Compiled: 2026-08-27 · Re-ranked: 2026-10-12 · 34 projects
J. Michael Duhart · Compiled: 2026-08-27 · Re-ranked: 2026-10-12 · 34 projects
Every project is scored on how much real distributed-systems engineering it carries, not on how impressive it looks. The question for each one: is it a core systems problem, and does it run?
| Weight | Signal | Why it is weighted this way |
|---|---|---|
| ×5 | Canonical DS primitives — consensus, partitioning, replication, event logs, idempotency, fan-out, backpressure | The heart of large-scale backend work. |
| ×4 | Production evidence — deployed, measured, has a runbook, has failure modes you can name | Separates "wrote a demo" from "carries a pager". |
| ×4 | Correctness under concurrency — race conditions found, fixed, and tested for | The hardest thing to get right, and the hardest to show without the code. |
| ×3 | Scale artifacts — sharding keys, partition design, consumer groups, TTLs, hot-key handling | What decides whether a design survives real load. |
| ×3 | Language fit — Go, Java, Python, C++ | The languages most backend platforms run on. |
| ×2 | Contract discipline — OpenAPI/AsyncAPI/protobuf, CI-enforced | Contracts tested in CI are what keep services from drifting apart. |
| ×2 | Written communication — design docs that state trade-offs and costs | A design that is not written down cannot be reviewed. |
| ×1 | Frontend / mobile / marketing | Real work, weighted lightly because this ranking is about backend systems. |
Each project is rated 0–5 per signal. Max score 120. Ratings are a judgment, not a measurement — treat differences under ~5 points as ties.
| # | Score | Project | One line | Where |
|---|---|---|---|---|
| 1 | 103 | Billboard Activity Graph | Transactional outbox → Kafka → three independent consumer groups → Cassandra + Postgres + realtime. At-least-once, idempotency paid explicitly at each sink. | app/BillboardActivityService |
| 2 | 106 | GlobalChat Realtime Messaging | 26K-line Go service: Cassandra chat, WebSocket fan-out, presence, push, calling signaling. Benchmarked and race-tested. | app/GlobalChatService |
| 3 | 101 | Match Service — Distributed Ranking | Geo-partitioned Cassandra ranking, Redis Streams consumer groups; a phantom-partition bug and a 952-message PEL leak, both fixed and written up. | app/MatchService |
The top three sit within 5 points of 120 — that is noise. GlobalChat edges the rubric on production evidence and breadth. The Activity Graph is listed first because it leads on the axis that decides a systems-design round: it is the canonical question, with every trade-off already written down. Open with the Activity Graph; bring GlobalChat as proof you have carried something this size in production.
| # | Score | Project | One line | Where |
|---|---|---|---|---|
| 4 | 90 | Solomon — Serving, Kubernetes & Autoscaling | FastAPI SSE/WS streaming + continuous batching, k3s + Helm + HPA scaled to 3 replicas, NetworkPolicy, dry-run-validated manifests. | Solomon/k8s |
| 5 | 89 | Solomon — LLM Platform (umbrella) | The whole pipeline end to end. Decomposed into the six projects below. | Solomon/ |
| 6 | 89 | FeedBench, One Contract, Three Runtimes | The production feed gateway plus full Go and Spring Boot ports to one contract, ramped to saturation and hit with six faults under hard caps. The data tier set every ceiling; two indexes beat any runtime (20x); a pre-registered paper. | app/FeedBench |
| 7 | 87 | Production Incidents, Root-Caused | Seven postmortems where the first theory was wrong: a Kafka loop that skipped failed offsets forever, a refresh rotation lost in a tunnel drop, a gateway 'active' and silent on a stalled Cassandra, an index rewritten under a live mmap, a gate that passed for three days. | app/GlobalChatService, app/AuthGateway, app/BillboardML, site/scripts/verify.mjs |
| 8 | 84 | Billboard Production Hardening | 60+ commits from forgeable auth to RS256 four-tier, 9 D1 tables, resumable upload, moderation, DMCA, CI contract gates. | app/workers/billboard_users |
| 9 | 83 | WebRTC Calling Plane | Signaling/media-plane audit: ICE/STUN/TURN, P2P vs orphaned SFU, a fatal concurrent-map race located. | docs/webrtc-chat/ |
| 10 | 83 | BillboardML, Audio Recognition & Recommendation | Fourth bit-exact Jamz fingerprint over a 457M-pair memory-mapped index (57/60 at 10 dB SNR), a live-mmap corruption found and fixed with atomic replace, and an album-excluded paired-bootstrap gate that keeps every learned model below CLAP out of serving. | app/BillboardML |
| 11 | 81 | Storefront Money Spine & Connect Payouts | One insert-then-process webhook guard for two services, int64 minor units, an append-only double-entry ledger, tier by Stripe price ID, and Connect payouts that needed on_behalf_of or every US ticket fails. | app/GlobalOneStorefrontGateway, workers/storefront |
| 12 | 80 | Media & Upload Infrastructure | R2 multipart ingest across five modes, IngestDO single-writer sessions, TUS resumability, a Go adapter bridging edge to Kafka/Redis. | app/GlobalCloudflareAdapter |
| 13 | 79 | Push & Notification Pipeline | Kafka → consumer → APNs, plus PushKit VoIP; dedupe where a duplicate is a second buzz on someone's phone. | app/GlobalChatService |
| 14 | 78 | Global Feed Gateway | One Worker on D1 serves every mode's feed; three stored axes (visibility, audience, moderation) pass through ONE projection whose SQL and row-check forms are proven equal on a 4,320-item matrix. Live, 244 tests. | app/GlobalFeedGateway |
| 15 | 75 | Solomon — Retrieval & Agent Tier | 4,757 lines of Go: chunk/embed/search/store, a bounded agent loop, a grounding guard with its own test, Kafka ingestion. | Solomon/retrieval |
| # | Score | Project | One line | Where |
|---|---|---|---|---|
| 16 | 73 | Platform Operations & CI/CD | systemd units including a restore-verify timer, Docker Compose stacks, two CI systems, gates that encode specific past defects. | deploy/, .github/ |
| 17 | 72 | Billboard Library Sync & The One 100 Charts | Offline-safe last-write-wins sync (clamped clocks, tombstones, per-field versions, final deletes, stale = 200) and a weekly regional chart derived from the idempotent play log, with session caps, sqrt scoring, fraud weighting and an outbox-announced freeze. | app/workers/billboard_users |
| 18 | 70 | Auth & Identity Platform | gRPC/Connect gateway, RS256 issuance, ACL, mode-sync, 24 protobuf contracts generating Go + Swift + TS. | app/AuthGateway |
| 19 | 70 | GlobalChat Messaging UI | iOS + web realtime clients with a transport/store/runtime split — and a wiring record that retracts three of its own conclusions. | IOS/.../GlobalChat |
| 20 | 69 | Realtime Gateway Trio | 48K lines of Go: three WebSocket gateways over Kafka + Cassandra, connection/session/presence separated. | app/gateways/ |
| 21 | 68 | Cloudflare Edge Platform | 10 Workers over D1, R2, KV, Durable Objects, Hyperdrive — including a WASM FFT fingerprinting DO. | app/workers/ |
| 22 | 65 | Solomon — Evaluation Gates & Promotion | Nine gates that can block a release, two of them latency and throughput; full artifact lineage to the running image. | Solomon/solomon/evaluation |
| 23 | 64 | Portfolio Platform on Workers | Next.js on a Cloudflare Worker with D1, R2 and an at-least-once publish queue guarded by conditional claims and a DLQ, plus a build gate that reconciles against the build's own prerender manifest after it passed blind for three days. | Portfolio/DesignByDuhart/site |
| 24 | 63 | Solomon — Training & Experiment Tracking | Noam + label smoothing, checkpoint/resume, MLflow, SHA256 run manifests. Val PPL 40.0 in 3 h on CPU. | Solomon/solomon/training |
| 25 | 62 | Dating Swipe Deck & Discovery UI | The largest mode in the app — and where the phantom-partition bug became visible. 49 audited findings with file:line. | IOS/TheOne/Dating |
| 26 | 61 | BoxOffice & the Moderator Console | "27 endpoints and curl" → a four-route operator console where a 502 on takedown is reported as a result, not a failure. | IOS/.../BoxOffice, /support/staff |
| # | Score | Project | One line | Where |
|---|---|---|---|---|
| 27 | 57 | OpenHouse Global | Real-estate service with 7 versioned forward-only CQL migrations and a buyer journey modeled as a state machine. | app/OpenHouseGlobal |
| 28 | 56 | Billboard Player — Audio UI & Engine | Full music player: AVPlayer behind an actor, MTAudioProcessingTap, live spectrum, on-device vDSP FFT fingerprinting. | IOS/TheOne/Billboard |
| 29 | 55 | Palantir J8 — Exhibit Factory | Ontology-driven financial pipeline; data-driven normalizer registry; fail-closed ingest. | Palantir/J8 |
| 30 | 54 | Multiplatform Clients (umbrella) | 611K lines Swift / 13 modes, 19-module Compose port, Next.js platform. Decomposed into the five UI projects. | IOS/, Android/ |
| 31 | 53 | Solomon — The Transformer | Built from the Annotated Transformer, component by component, every deviation justified in writing. KV cache proven equal to full recompute. | Solomon/solomon/model |
| 32 | 51 | Web Platform UI | Every product mode in one Next.js app, compiled against the same protobufs the backend serves. Playwright + vitest. | app/web-platform |
| 33 | 46 | Solomon — Corpus, Tokenizer & Data Governance | 130M tokens cleaned and deduped, SentencePiece BPE (0 UNK), data card with contamination checks. | Solomon/solomon/data |
| 34 | 39 | Technical Documentation Corpus | Three 17–20 chapter manuals with gap registers — including a 14/52 Spotify parity analysis. | docs/ |
Two umbrella entries decompose into the detail projects. They are listed once each and are not double-counted:
| Umbrella | Decomposes into |
|---|---|
| Solomon platform | Model · Corpus · Training · Eval gates · Serving/K8s · Retrieval/agent |
| Multiplatform clients | Billboard player · BoxOffice console · Dating swipe · Chat UI · Web platform |
Activity graph → Match Service → FeedBench → Incidents
Activity graph → BillboardML → Media ingest → Sync & charts
Storefront money spine → GlobalChat → Auth → Palantir J8
Billboard player · BoxOffice + moderator console · Dating swipe deck · GlobalChat messaging · Web platform
Model → Corpus → Training → Eval gates → Serving/K8s → Retrieval/agent
Rendered, self-contained HTML in ../infographics/:
| File | What it shows |
|---|---|
01-portfolio-ranking.html | All projects as a scored tier board (the site version reads the live ranking) |
02-activity-graph.html | The outbox → Kafka → three-consumer pipeline, drawn |
03-platform-map.html | Every service in /srv and who calls whom |
04-scale-dashboard.html | The numbers: LOC, services, datastores, tests |
05-skills-matrix.html | Skills mapped to the evidence for each |
06-solomon-pipeline.html | Corpus → training → eval gates → promotion → k8s |
/srv holds ~4.3M lines of authored code across 13 backend services, 10
edge Workers, 3 realtime gateways, 4 datastores, and 3 client platforms, plus
a from-scratch LLM platform and three book-length engineering manuals.
Three things stand out, and the other thirty-one are supporting evidence:
The rest is range, and there is a great deal of it.