D
Don Martirez
Tailored ApplicationDisney Entertainment & ESPN Product & Technology (DEEP&T) — Business Operations AI Engineer
AI Engineer • 4+ Years Experience • Glendale, CA / Hybrid

I build and maintain production GenAI applications — grounded conversational systems, agentic workflows, and observable pipelines.

Software engineer specializing in Python-based generative AI systems, conversational interfaces for enterprise operational data, and deterministic retrieval workflows. Hands-on experience developing LangGraph multi-agent DAGs, GraphRAG in Neo4j, MCP-style tool integrations, and full-lifecycle LLMOps with golden evaluation suites.

Python & FastAPILangGraph & Multi-Agent DAGsGraphRAG & Neo4jMCP & Tool CallingVector Search & EmbeddingsLLMOps & Golden Set EvalsDocker & Cloud RunCursor & Claude Code
Location & Availability
Duarte, CA (91010) • Glendale hybrid ready • Immediate start • B.A. Media Arts & Design
Focus Areas
Conversational AI platforms, natural language over operational data, semantic ingestion & chunking, structured prompt design, agentic tool-calling, and production observability.
Engineering Velocity
Proficient with AI-assisted developer workflows (Cursor, Claude Code, Gemini CLI) for rapid service scaffolding, comprehensive test coverage, and clear operational documentation.
Section 01 — Role Alignment • DEEP&T AI Engineer

How My Background Maps to Disney DEEP&T

Proven experience building conversational AI platforms, grounding responses in enterprise source data, and maintaining resilient production GenAI services.

01
Python GenAI Application EngineeringStrong Python, backend services, web applications & operational data connectivity
4+ years shipping production software. Built and containerized multiple production applications (the3pmdaily.com, artstache.app, don-the-imaginator.com) using Python, FastAPI, and Docker. Implemented asynchronous APIs, rigid Pydantic schema validation, and middleware connecting web apps with backend microservices.
02
Retrieval & Grounding WorkflowsSource-backed AI responses, embeddings, vector search, semantic chunking & metadata
Engineered deterministic GraphRAG in Neo4j AuraDB with LangGraph conditional DAGs. Modeled Lowenfeld's stages (1947) as property graph triples enforcing sequence: (:Stage)-[:PRECEDES]->(:Stage). Enforced a fail-closed grounding gate (is_grounded_in_neo4j returns null if 0 nodes match or confidence < 0.75). Verified Bolt Cypher query latency at ~90.07ms median local with an end-to-end <800ms target SLA.
03
Agentic Workflows & MCP-Style Tool CallingTool use, function calling, API actions, multi-step reasoning & protocol integrations
Implemented custom tool-calling engines rendering generative client UI components in real time. Designed MCP-style structured endpoints allowing conversational agents to execute deterministic Python tools (DCF calculations in 3.63ms median with 92% token savings, appointment scheduling, vector search). Client-side Pocket-Synth traps 80% of common queries locally with $0 LLM cost.
04
LLMOps, Observability & Boundary-First TestingLogging, monitoring, latency tracking, cost management, golden datasets & troubleshooting
Curated 50-vector golden evaluation datasets with 101 automated assertions running in 170ms in CI/CD (<800ms SLA). Mutation testing verified invariant resilience by catching 12 out-of-order failures upon edge deletion. Built automated heartbeat monitors for database pool warmups. Heavy compute runs locally to optimize cloud infrastructure costs to ~$18/month.
05
Modern Engineering Velocity & Cloud DeploymentCursor, Claude Code, Docker, CI/CD, and cloud environments (GCP production + Azure concepts)
Required daily use of AI coding tools (Cursor, Claude Code, Gemini CLI) for high-velocity full-stack engineering, test automation, and documentation. Deployed containerized microservices to Google Cloud Run with automated CI/CD; familiar with Azure OpenAI, Azure Functions, and App Service architectures.
Section 02 — Production Case Studies

Production GenAI Systems

Conversational Platforms • Grounding • LLMOps
01 · Deterministic Math Engine
~800 → 4
15m Bars → Score ≥ +4 Setups
TA-Lib C-Bindings in 4.2s • Live Tape Only
02 · Unit Economics & Cost
~$18/mo
Total Cloud Infra Cost
>90% Margin • Heavy Compute Local
03 · Automated CI/CD Regression
101 Assertions in 170ms

50 golden market vectors validate Pydantic coercion and null-math suppression (<800ms SLA).

No Badge > Fake Badge • CI/CD
04 · LangGraph Orchestration
9-Agent StateGraph DAG

9 investment styles evaluate fundamental risk and debt walls without calculating or hallucinating prices.

LangGraph • Cloud Run • Redis
Architecture: Solo-operated closing terminal with TA-Lib C-bindings, LangGraph 9-agent DAG, and Cloud Run serve
Closing Terminal • Python & TA-LibLangGraph • Cloud Run • Live

3PM Daily: Solo-Operated Market Closing Terminal

Problem

Between 1:00 PM and 3:00 PM PT, active market participants face auction prints (MOC) and earnings releases. Monolithic dashboards cause cognitive overload across hundreds of data points.

Engineering Solution

Engineered a 4-artifact pipeline: Ingests ~800 15-min bars into MySQL; runs TA-Lib C-bindings scanning ~827 symbols in 4.2s for 1x ATR stops; executes a LangGraph 9-agent DAG stress-testing fundamental moats; publishes 4 setups meeting Confluence Score ≥ +4 via Cloud Run + Redis.

Verified Outcome

Runs for ~$18/month in cloud infrastructure with >90% margin. 101 assertions across 50 golden vectors passing in 170ms in CI/CD. Zero LLM price hallucination permitted in client pipeline.

01 · GraphRAG Triples
Neo4j AuraDB Knowledge Graph

Lowenfeld stages (1947) modeled as property graph triples: (:Stage)-[:PRECEDES]->(:Stage). Graph structurally enforces chronological sequence.

Neo4j • Cypher • Graph RAG
02 · Ingestion & Grounding
5-Node LangGraph DAG

Multi-node conditional DAG with explicit grounding gate (is_grounded_in_neo4j returns null below 0.75 confidence to prevent hallucinated badges).

LangGraph • Grounding Gate
03 · Telemetry & Invariant
50/50 Passed + Mutation Test

Bolt Cypher ~90.07ms median local (50 runs). Mutation test caught 12 out-of-order failures upon edge deletion. Target SLA <800ms.

~90.07ms Median • 50/50 Passed
Architecture: Source-backed GraphRAG with Neo4j property graphs, LangGraph conditional DAG, and Canvas memory buffer
GraphRAG • Source Grounding • LangGraphNeo4j • Python • Live

Artstache: Source-Backed Pedagogical GraphRAG System

Problem

Parents reviewing children's artwork at 6:15 PM face paper clutter and fatigue. Vector search conflates a 4yo tadpole with a 10yo comic, risking out-of-sequence pedagogical recommendations.

Engineering Solution

Modeled Viktor Lowenfeld's (1947) stages into Neo4j property graph triples. Built a 5-node LangGraph orchestration DAG in Python with an explicit grounding validation gate (is_grounded_in_neo4j) returning null below 0.75 confidence. Stripped all image EXIF data in an <80KB in-browser Canvas buffer designed with COPPA privacy principles in mind.

Verified Outcome

Bolt Cypher ~90.07ms median local (50 runs, raw: latency_runs.jsonl). [:PRECEDES] graph relationships structurally prevent out-of-order milestones (50/50 passed; mutation test caught 12 failures). No-Line Rule paper elevation system.

01 · Bifurcated IA Contract
Reserved / vs. Experimental /lab

Clean editorial landing for 30s scanning (0.00 CLS median, 15.56ms cascade); deep interactive tool sandbox isolated in /lab.

Funnel: 20% → 0% • N~10/mo
02 · Client-Side Pocket-Synth
80% Local Query Trap

40/50 queries trapped client-side in browser memory with $0 LLM cost and <10ms P50 latency across 2,500 test runs.

80% Trap (40/50) • $0 Cost
03 · Grounded Python Tools
FastAPI & Deterministic Tools

Python DCF model runs in 3.63ms median with 92% token savings (1850→140). Local watchdog daemon warms database pools.

DCF 3.63ms • Local Watchdog
Architecture: Bifurcated IA with Pocket-Synth local trapping, deterministic FastAPI microservices, and generative React cards
Conversational Platform • Tool CallingFastAPI • Python Tools • Live

don-the-imaginator.com: From Gated Friction to Open IA

Problem

Mandatory Firebase auth gate created severe drop-off: Firestore SiteAnalytics revealed Funnel: 20% signup, 0% activation (N~10/mo). Exclusivity hypothesis failed; technical evaluators demand immediate proof without friction.

Engineering Solution

Dismantled the auth gate. Bifurcated information architecture into a reserved editorial landing for rapid review and an isolated `/lab` sandbox for technical diligence. Built client-side Pocket-Synth trapping 80% of queries locally ($0 LLM cost), paired with a FastAPI backend executing deterministic Python tools (DCF in 3.63ms median) and generative React cards.

Verified Outcome

Zero mandatory auth friction with immediate <5s proof. Verified Test 1 (Theme Engine, 250 swaps): 0.00 CLS median, 15.56ms cascade. Local watchdog daemon maintains warm pools (disclosed limitation; next: Cloud Scheduler).

Section 03 — Engineering Standards & LLMOps

How I Build Resilient GenAI Systems

Rigorous production standards from schema design and deterministic grounding to continuous observability and regression testing.

01
Standard 01
Python Microservices & API Integration
FastAPI services with asynchronous request handling, Pydantic schemas, and structured error boundaries connecting web interfaces to external data stores.
02
Standard 02
Deterministic Grounding & GraphRAG
Property graph modeling in Neo4j and vector search indexers that enforce source-backed responses and eliminate hallucinated sequences via [:PRECEDES] constraints.
03
Standard 03
Agentic Workflows & MCP Tool Calling
LangGraph orchestration DAGs with human-in-the-loop validation, multi-step tool execution, and real-time generative UI component rendering.
04
Standard 04
Full-Lifecycle LLMOps & Observability
Automated telemetry, structured JSON logging, token cost tracking, and heartbeat monitors maintaining database pool availability.
05
Standard 05
Golden Datasets & Boundary-First Testing
Pre-deployment validation suites using 50-prompt golden datasets, 101 automated assertions in 170ms in CI/CD, and mutation testing before production release.
06
Standard 06
Containerization & Developer Velocity
Docker containerization and Cloud Run deployments accelerated by modern AI developer workflows (Cursor, Claude Code, Gemini CLI).
Dedicated to enterprise AI safety, access control, and source provenanceCollaborative engineering with senior teams • Clear technical documentation & retrospectives