# Résumé Bullets — pre-sorted by employer

Every bullet below is traceable to code in `/srv`. Nothing is inflated; where a
number appears it came from a count or a written report, not an estimate.

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## The six that go on every version

- Designed and shipped an **event-driven activity pipeline** — transactional Postgres outbox → Kafka topic (6 partitions, keyed by actor) → **three independent consumer groups** materializing into Cassandra, Postgres, and a realtime channel — with at-least-once delivery deduplicated at each sink by a stable idempotency key.
- Built and operate a **26K-line Go realtime messaging service** on Cassandra, Redis, and Kafka serving WebSocket chat, presence, push, and WebRTC signaling; contract-tested against both OpenAPI and AsyncAPI with a **coverage test that fails the build on drift**.
- Diagnosed and fixed a **Cassandra phantom-partition defect** in a geo-sharded ranking pipeline where upsert-on-write with an inferred partition key created one orphan row per user per region and leaked nameless records into production user feeds.
- Diagnosed and fixed a **Redis Streams consumer-group leak** in which unacknowledged failures accumulated **952 pending entries** with no reclaim path; implemented aged-entry reclaim so failed work retries instead of being orphaned.
- Took a service from **forgeable authentication to RS256 four-tier JWT verification** with identity bound to the token, added **9 missing database tables**, closed contract drift between client and server, and enforced all of it with the first CI the service ever had (typecheck, tests, end-to-end, contract diff).
- Trained a **transformer language model from scratch in PyTorch** (no HuggingFace) and built the platform around it: 9-gate evaluation as a promotion blocker, containerized streaming inference (SSE + WebSocket, continuous batching, KV cache), deployed on **k3s + Helm with HPA scaling to 3 replicas under load**; 86 % test coverage, load-tested at 198 requests / 0 failures / p95 2.7 s against a 6 s SLO.

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## For Google

Emphasis: scale reasoning, correctness, written design, Kubernetes, Go.

- Architected around a hard platform constraint — Cloudflare Workers cannot open raw TCP sockets, making Kafka and CQL permanently unreachable from the edge — by relocating the consumer tier to a host-resident Go service and connecting it through a transactional outbox rather than a dual write.
- Implemented **hybrid feed fan-out** (push below ~10k–50k followers, pull above) as a tuning constant rather than an architectural fork, with **LexoRank fractional ordering** so reordering one item does not rewrite every row after it.
- Authored three book-length engineering manuals (17–20 chapters, mermaid architecture diagrams) each ending in a **numbered gap register and remediation roadmap**; separated verified findings from inferred ones in dedicated documents.
- Located a **fatal concurrent-map access** in a Go WebRTC call path — an unrecoverable runtime error that terminates the process and drops every connection on the host — and documented it with a remediation entry rather than a retry wrapper.
- Deployed a multi-service Helm chart to k3s (inference, orchestrator, members, retrieval, search, NetworkPolicy, in-cluster MLflow) validated with `kubectl apply --dry-run=server`.

## For Spotify

Emphasis: music domain, audio DSP, streaming, feeds, edge delivery.

- Built the music mode's **activity graph**: playlists, follows, feed, and posts as one event log with one materializer rather than four parallel pipelines, with system playlists as reserved-id rows and a single `follows` table discriminated by `target_type`.
- Implemented **R2 multipart resumable upload** (10 MiB equal parts, audio probe, Durable Object session coordination) and made TUS uploads genuinely resumable; made `publishDraft` atomic.
- Shipped **audio fingerprint recognition**: an FFT constellation matcher compiled to WebAssembly (`kissfft.wasm`) running inside a Cloudflare Durable Object, with an on-device Swift/vDSP counterpart in the iOS client.
- Built **R2 range-request streaming** for audio delivery at the edge, and a 10K-line, 65-route library/playlist/charts API over D1 and Postgres.
- Wrote a **feature-by-feature parity analysis against Spotify** scoring the system at 14 of 52, then burned the gap register down across ~60 numbered commits.
- Delivered the iOS music client: 128 files / 57.7K lines, with an `AudioEngineActor` isolating AVPlayer behind Swift structured concurrency.

## For a bank / financial institution

Emphasis: correctness, auditability, contracts, fail-closed behavior, security.

- Built an **ontology-driven financial exhibit pipeline** (Palantir Foundry, Python Tier-2 transforms + React widget) with a data-driven normalizer registry per input shape, label-first reference qualification, and **fail-closed ingest** — an ambiguous case is WARN-blocked rather than silently producing a wrong exhibit.
- Made **API contracts the enforced source of truth**: OpenAPI/AsyncAPI plus 24 protobuf definitions generating Go, Swift, and TypeScript clients from one schema, with contract-diff and shadow-type gates in CI.
- Built the **identity and authorization plane**: ConnectRPC/gRPC gateway with RS256 token issuance and verification, ACL servicer, claims caching, entitlement mode-sync, and an auth event bus — asymmetric signing so verifiers never hold signing material.
- Implemented **content moderation and DMCA compliance** end to end: review-before-publication, report intake, decision queue, takedown, plus a three-way automated classifier in front of the human queue with its thresholds, costs, and **documented limits** — what the classifier cannot catch is written down.
- Conducted a full-platform security and architecture audit that identified dual backends serving one function, a three-way identity split, three parallel chat schema families, and credentials committed to a repository — each reported with location and remediation rather than quietly patched.

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## Numbers you can quote

| Claim | Figure | Source |
|---|---|---|
| Authored code in `/srv` | ~4.3M lines | file census, vendored trees excluded |
| Go realtime messaging service | 26,176 lines / 77 files / 29 test files | `app/GlobalChatService` |
| Go ranking service | 33,638 lines / 51 files | `app/MatchService` |
| Go realtime gateways | 48,582 lines | `app/gateways` |
| Edge Worker (library/feed API) | 10,581 lines / 65 routes | `app/workers/billboard_users` |
| Swift client | 611,426 lines / 1,200 files / 13 modes | `IOS/TheOne` |
| Kotlin/Compose port | 19 modules | `Android/` |
| Protobuf contracts | 24 authored | `app/proto` |
| Kafka partitions / consumer groups | 6 / 3 independent | `app/BillboardActivityService` |
| LLM eval gates passed | 9 of 9 | `Solomon/STATUS.md` |
| LLM load test | 198 reqs, 0 fail, p95 2.7 s vs 6 s SLO | `Solomon/reports/testing` |
| Python test coverage (Solomon) | 86 %, 62/62 | `Solomon/STATUS.md` |
| Redis PEL entries leaked before fix | 952 | `app/MatchService/stream_reclaim.go` |
| Spotify feature parity measured | 14 / 52 | `docs/billboard/14-SPOTIFY-PARITY.md` |