Expertise • Tools • Impact

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A structured view of the technical stack, automation patterns, BI work, domain knowledge, and operational problem-solving behind the Lopez Data Works portfolio.

Data systems & analytics

Python, SQL, BI, reporting models, and decision-ready data workflows.

Automation workflows

Repeatable jobs, audit-ready outputs, schedulers, and delivery pipelines.

Apps & APIs

FastAPI, Flask, React, internal tools, and operational app experiences.

Inventory & pricing intelligence

Procurement, replenishment, inventory health, pricing logic, and margin support.

Skill system map

Filter capabilities by domain.

Showing 28 capability groups.

Analytics & BI

Deadstock analytics, markdown logic, and trend comparison workbooks

🧊

Deadstock Classification

Convert last-sale age, purchase/receipt age, on-hand quantity, landed cost, Dealer Net, and status fields into actionable stale, dormant, dead, and never-sold buckets.

Inventory AgingDeadstockPricing Buckets
🏷️

Markdown Recommendation Logic

Model stale pricing rules, landed-cost recovery, cost-based liquidation, do-not-reorder flags, weak-demand warnings, and true-dead candidate review lists.

MarkdownsDNetReorder Risk
📊

Two-Run Trend Workbooks

Compare prior and current deadstock runs to surface newly dead parts, recovered items, removed inventory, worsened severity, improved severity, and bucket-level value movement.

OpenPyXLTransitionsExecutive Summary

Automation

Customer sales analytics and Excel reporting automation

📈

Weighted profitability modeling

Calculate customer and manufacturer summaries using aggregate-based weighted metrics for margin, profit after expenses, unit economics, sales share, and quantity share.

PandasProfitabilityWeighted KPIs
📊

Excel workbook generation

Create formatted workbooks with KPI bands, grand totals, hidden raw data, freeze panes, filters, number formats, autosized columns, and conditional formatting.

OpenPyXLExcel AutomationReporting
🔁

Period-over-period analysis

Compare current and previous sales files by customer and manufacturer, identify growth/decline trends, flag high drops, and surface top movers.

POP AnalysisRisk FlagsTop Movers

Analytics & BI

Power BI semantic modeling and operational dashboard design

📊

Multi-page BI design

Design report pages around operational questions such as ABC classification, DSI, replenishment, procurement, velocity, dormant inventory, dead stock, and dissipation.

Power BIDashboard UXOperations BI
🧮

DAX measure engineering

Build KPI measures, weighted calculations, inventory-value metrics, stockout-risk indicators, action counts, and conditional-formatting logic.

DAXMeasuresConditional Formatting
🧱

Semantic model structure

Connect analytics tables, inventory snapshots, item master records, ship documents, and customer group dimensions into a reusable reporting layer.

Semantic ModelRelationshipsData Modeling

Analytics & BI

Market analytics, forecasting models, and decision-support dashboards

📈

Financial Data Extraction

Pull crypto and stock market history, metrics, dividends, recommendations, and comparable ticker data from public market-data sources.

yfinancePandasMarket Data
🧠

Forecasting & Signals

Prototype ARIMA, SARIMA, LSTM, random-forest forecasting, technical indicators, anomaly detection, and buy/sell/hold-style decision summaries for analysis only.

ARIMALSTMTechnical Indicators
📊

Interactive Analytics UI

Build Dash/Plotly dashboards with tabs for forecasts, portfolio allocation, sentiment, crypto metrics, multi-ticker comparisons, and downloadable visual analysis.

DashPlotlyDashboard UX

Automation

Webhook API design and event logging

📡

Webhook Receivers

Build FastAPI endpoints that receive external system events, support verification routes, enforce authentication, and return predictable status responses.

FastAPIHTTPBasic Auth
🧾

Payload Validation

Normalize case-varying keys, map source aliases to canonical fields, validate webhook payloads with Pydantic models, and stamp UTC load timestamps.

PydanticNormalizationUTC Logging
🛢️

Event Persistence

Persist event activity into append-only JSON/CSV logs and SQL tables so webhook activity can be audited, downloaded, and used for downstream reporting.

Azure SQLJSON/CSVAudit Trail

Analytics & BI

Weekly file generation, audit workbooks, and partner-ready exports

📦

Inventory Export Automation

Build repeatable workflows that pull inventory from APIs or read the latest downloaded CSV/XLSX source file, then standardize it into a clean reporting dataset.

PythonAPICSV/XLSX
🧾

Audit-Ready Workbooks

Create Excel outputs with summary, raw, dropped-row, custom-field, column, inferred-value, and value-audit sheets so file counts and exclusions are explainable.

PandasOpenPyXLXlsxWriter
📬

Stakeholder Delivery

Bundle generated workbooks into timestamped ZIP packages and deliver them through SMTP with recipient personalization, attachment-size checks, and failure notifications.

SMTPZIPdotenv

Systems

Core Capabilities

⚙

Data Automation

Automate repetitive processes and data workflows.

⇄

ETL / API Pipelines

Build robust pipelines to extract, transform, and load reliable data.

▥

Business Intelligence Dashboards

Create interactive dashboards that turn data into action.

▣

Inventory & Operations Analytics

Bring clarity to inventory, operations, and supply chain data.

⌨

Web Apps & Internal Tools

Build custom web apps that solve real business problems.

☷

Reporting Systems

Deliver automated reports and subscriptions that save time.

Automation

Operational feed automation

📡

FTP/FTPS Feed Automation

Partner file publishing, atomic upload patterns, run manifests, remote validation, and feed health checks.

FTP/FTPSCSV FeedsMonitoring
🧾

Audit & Manifest Design

Run summaries, row counts, field-source auditing, JSON manifests, and traceable outputs for scheduled jobs.

Audit CSVJSONOps
📈

Drift & State Tracking

Feed metrics, historical baselines, inventory events, and state snapshots that help detect changes across runs.

StateDriftQuality

Automation

Automated file delivery and stakeholder reporting

📦

Bundle Automation

Package multiple operational CSV/XLSX outputs into timestamped ZIP files for controlled delivery.

ZIPFile ManifestOps
✉️

Email Delivery Workflows

SMTP-based delivery, environment configuration, recipient parsing, delivery windows, and attachment handling.

SMTPEmailMessage.env
🧭

Final-Mile Reporting

Connect generated reports and feed outputs to stakeholder communication so operational files actually reach the business.

ReportingDeliveryAutomation

Automation

Changed-only reporting orchestration

🧭

Stage Registry Design

Define named pipeline stages, dependencies, source folders, output folders, and runnable scripts in one controlled registry.

RegistryDependenciesCLI
🧬

Input Manifest Detection

Compare file and folder fingerprints using size, modified time, and optional content hashes so unchanged stages can be skipped safely.

SHA-256ManifestsSkip Logic
📋

Run-State Auditing

Record stage status, start/end timestamps, commands, skip reasons, file manifests, and dry-run plans for repeatable reporting operations.

JSON StateLogsDry Run

Data Engineering

Stateful incremental pipelines

🧠

Run-State Management

JSON state files, changed-run manifests, processed-run baselines, and backup-safe state updates for repeatable pipeline execution.

JSON StateManifestsBackups
⚡

Incremental ETL Design

Detect new or changed folders, process only required source data, upsert stable master outputs, and skip unnecessary full-history rebuilds.

IncrementalUpsertHashing
🧾

Pipeline Orchestration

Daily runners, dry-run mode, stage logging, required/optional step handling, PowerShell launchers, and Windows Task Scheduler readiness.

OrchestrationPowerShellTask Scheduler

Automation

Browser automation and web-portal data extraction

🎭

Playwright Automation

Automated login, session reuse, page readiness checks, pagination, sorting, and portal navigation for business workflows that do not expose clean APIs.

PlaywrightBrowserSession State
🧩

Dynamic Table Extraction

Header/row scraping from dynamic grids, jqGrid parsing, detail-page loops, and quote-level folder outputs for traceability.

jqGridCSVJSON
🗂

Evidence File Capture

Saved XML table extraction, download capture, per-quote output packaging, and Excel summary workbooks for review.

XMLOpenPyXLAudit

Data Engineering

Pipeline acceleration and legacy workflow modernization

🧭

Step Registry Orchestration

Turn many standalone reporting scripts into one controlled runner with named stages, ordered execution, and single-step reruns.

CLIOrchestrationRunbooks
🧬

Fingerprint-Based Skipping

Use input file size, modified timestamp, output markers, and JSON step state to avoid launching heavy scripts when nothing changed.

StateFingerprintsSkip Logic
🔁

Safe Legacy Migration

Wrap trusted legacy scripts first, then gradually replace the slowest stages with native, vectorized modules while preserving existing outputs.

Legacy WrappersPandasMigration

Data Engineering

SQL history loading and canonical de-duplication

🛢

Azure SQL Load Patterns

Schema/table creation, append-only loading, SQLAlchemy engines, and database-backed history tables for reporting.

Azure SQLSQLAlchemyETL
🧬

Canonical Key Design

Uppercase, trimmed, business-grain keys that align Python de-dupe logic with SQL Server uniqueness behavior.

Natural KeysDe-DupeIntegrity
🧹

CSV Normalization

Header mapping, part-number cleanup, Month/Year validation, numeric coercion, and strict keep-list controls.

PandasValidationCSV

Analytics & BI

Pricing analytics, snapshot caching, and period-over-period reporting

💰

DNet/List Movement Analytics

Classifies cost and list appreciation/depreciation, identifies new/removed parts, and creates manufacturer-level movement summaries.

Price AnalyticsPOPTrend Logic
🧊

Snapshot Cache Design

Moves expensive workbook parsing into reusable normalized monthly snapshots so repeat reporting jobs can run faster.

ParquetCachingPerformance
📊

Executive Reporting Outputs

Builds compact summary workbooks while streaming large detail records to CSV/JSONL and dataset files for downstream analysis.

OpenPyXLCSVJSONL

Apps & APIs

Flask/Dash analytics portal development

🌐

Internal Analytics Apps

Build Dash/Flask portals that turn lookup scripts, tables, uploads, and exports into user-facing web workflows.

FlaskDashBootstrap
🔐

Authentication Workflows

Login, registration, password hashing, user sessions, verification links, and environment-based email configuration.

Flask-LoginBcryptSMTP
📊

Upload-Driven Analysis

Parse CSV/XLSX uploads, preview data quality, summarize numeric fields, analyze monthly trends, and export results.

PandasDataTablesPlotly

Apps & APIs

eBay API operations and seller analytics extraction

🛒

Marketplace API Integration

Order, payout, cancellation, traffic, finance, and competitive pricing extraction across multiple eBay API surfaces.

Fulfillment APIFinances APIAnalytics API
🔐

OAuth & Token Handling

User-token and app-token flows, refresh-on-401 behavior, scope separation, and environment-based credential configuration.

OAuthRefresh Flow.env
📈

Seller Ops Datasets

Normalized CSV/JSON outputs for orders, line items, fees, payouts, listing traffic, competitive prices, and API rate-limit visibility.

PandasCSV/JSONProfitability

Data Engineering

Cloud ETL orchestration and Azure-ready data operations

☁️

Cloud-Ready ETL Jobs

Dockerized Python jobs designed for scheduled cloud execution, local dry-runs, and controlled sync between local folders and Blob Storage containers.

DockerAzure JobsBlob Storage
🧭

Dependency-Aware Orchestration

Manifest-driven pipeline steps with dependencies, freshness checks, force rebuilds, dry-run mode, critical/non-critical step handling, and run summaries.

DAGStateful RunnerCLI
🧠

Inventory Intelligence Layer

Transforms raw API and inventory files into lead time, replenishment, procurement, ABC, DSI, dead stock, dormant, dissipation, and velocity outputs.

PandasSQL ServerAnalytics

Data Engineering

Master-data ingestion, validation, and SQL history modeling

🧾

Canonical Master Data Modeling

Normalize messy CSV headers into controlled canonical fields for part numbers, manufacturers, countries of origin, HTS codes, materials, and tariff attributes.

Canonical ColumnsPandasMaster Data
🛡️

Pre-Load Data Validation

Validate required fields, column lengths, numeric ranges, and HTS formatting before records are allowed into SQL-backed reporting tables.

ValidationQuality GatesHTS
🕰️

SQL History Patterns

Use staging tables, stored-procedure upserts, load batch IDs, source names, current views, and effective-dated history records for traceable analytics.

Azure SQLT-SQLHistory Tables

Data Engineering

OEM reference-data ingestion and incremental SQL loading

🔍

Reference Data Ingestion

Load OEM lookup files from local CSV or cloud Blob sources and transform raw partner/reference fields into a SQL-ready table shape.

CSVAzure BlobReference Data
📅

Flexible Year Parsing

Convert values like single years, year ranges, mixed separators, and “Various” into normalized YearStart and YearEnd fields for lookup analytics.

RegexData CleaningPandas
🧹

Append-Only De-Duplication

Use existing SQL records as the comparison set, filter by OEM number, and append only new lookup rows to prevent repeat loads.

Azure SQLDe-DupeSQLAlchemy

Data Engineering

Catalog ingestion, SQL validation, and incremental de-duplication

📦

Catalog ETL

Load catalog exports from CSV, TXT, Excel, or cloud Blob sources and convert them into a consistent reporting-ready shape.

CSV/XLSXAzure BlobPandas
🧹

Field Normalization

Standardize headers, trim strings, coerce quantities, clean currency values, and preserve only validated target columns.

Data CleaningMSRPQty
🛢️

SQL Append Patterns

Validate target schema/table availability, compare existing natural keys, and append only new rows into SQL-backed reference tables.

Azure SQLSQLAlchemyDe-Dupe

Data Engineering

PDF extraction, document ETL, and reconciliation automation

📄

Document Data Extraction

Use pdfplumber, text extraction, and regex fallbacks to turn invoice PDFs into structured rows that can be audited and analyzed.

PDF ParsingpdfplumberRegex
🧾

Invoice/Credit Memo Modeling

Parse invoice headers, line items, credit memo records, money fields, order IDs, shipping totals, and source-page traceability.

PandasExcelCSV
🔁

Marketplace Reconciliation

Map changing eBay export headers, join transaction data to supplier invoice records, and publish reconciliation workbooks for margin review.

eBay ExportsHeader AliasesProfitability

Apps & APIs

AI-assisted analytics application development

🤖

LLM Tool Routing

Design assistants that map natural-language business questions to curated tools instead of unrestricted database queries.

OpenAITool CallsPrompt Design
🛡️

SQL-Safe Analytics Access

Wrap known analytics tables in parameterized Python functions, shape outputs consistently, and keep the AI layer away from free-form SQL generation.

FastAPIAzure SQLPydantic
🖥️

AI Product UI

Build React/Vite workspaces with domain tabs, starter prompts, answer cards, result tables, detail drawers, debug views, and export actions.

ReactViteUX

Data Engineering

Analytics API development, SQL-safe endpoints, and dashboard delivery

⚙️

FastAPI Analytics Services

Design modular API routers for KPIs, trends, sales, inventory, supply chain, eBay performance, alerts, forecasts, pagination, and health checks.

FastAPIRoutersHealth Checks
🛡️

SQL-Safe Query Design

Separate T-SQL files from endpoint code, bind filter parameters, use read-only credentials, and make outputs predictable for dashboards and exports.

Azure SQLSQLAlchemyParameterized SQL
📊

Dashboard API Consumption

Build lightweight front ends that collect filters once, call multiple endpoints, render KPI cards/charts/tables, and trigger CSV/XLSX downloads.

Chart.jsTailwindExports

Automation

Automated file delivery, stakeholder notifications, and run failure alerting

📧

Stakeholder Email Automation

Build SMTP workflows that personalize messages, send to defined recipient maps, and deliver operational files without manual attachment handling.

SMTPEmailMessagePersonalization
📦

Artifact Bundling

Collect output files, skip missing artifacts safely, create timestamped ZIP packages, and enforce maximum attachment-size limits before delivery.

ZIPFile ChecksSize Guardrails
🚨

Failure Notifications

Wrap operational delivery jobs in exception handling so failures trigger alert emails with error context instead of silently breaking downstream communication.

TracebacksAlertsRun Monitoring

Apps & APIs

Inventory scanning applications and cycle-count workflows

🏷️

Barcode & Part Normalization

Normalize scanner input, stripped suffixes, spaces, punctuation, and alternate part-number formats so scans resolve to business records.

BarcodeNormalizationLookup
📦

Warehouse Workflow Apps

Build FastAPI-backed tools for scan capture, inventory lookup, BIN updates, receiver validation, cycle count progress, and exportable audit records.

FastAPIAzure SQLCycle Count
📱

Static Ops Interfaces

Use lightweight HTML/JS dashboards with manual input, hardware wedge support, camera scanning, tabbed workflows, and business-user-friendly screens.

HTML/JSScanner UIExports

Inventory & Pricing

Pricing policy modeling, margin guardrails, and buy recommendation scoring

📐

Policy-Based Pricing Models

Translate margin targets, Dealer Net floors, List Price floors, deduction assumptions, and rounding rules into repeatable pricing logic.

DNetGross MarginNet Margin
🧪

QA-Gated Decision Pipelines

Validate source inventory before pricing, stage accepted-only rows, and preserve rejected-row outputs and run logs for auditability.

QAValidationRun Logs
🚦

Recommendation Scoring

Build rule-based decision layers that score profitability, realism, risk, confidence, and stock position into operational action labels.

ScoringRiskProcurement

Analytics & BI

Hit comparison, inventory exposure scoring, and Excel audit workbooks

🎯

Normalized Match Logic

Clean part numbers, remove punctuation and formatting noise, compare exact text hits against normalized hits, and preserve no-hit/duplicate review tabs for auditability.

Part MatchingNormalizationDuplicates
🚦

Inventory Risk Scoring

Translate status, on-hand quantity, extended Dealer Net exposure, and cost-adjustment deltas into red/yellow/green risk bands with explanation strings.

Risk BandsDealer NetExposure
📘

Executive Audit Workbooks

Produce analysis and audit Excel files with KPI cards, executive summaries, formatted detail tabs, penny-cost review sheets, and append-only run logs.

OpenPyXLAudit LogsKPI Cards

Technical stack

Tools organized by how I use them.

The stack is grouped around the work it supports: building logic, modeling decisions, delivering applications, and maintaining reliable data platforms.

Working principle

Choose the tool that fits the workflow, then make the output repeatable, explainable, and useful.

Languages & query

Core logic, transformations, modeling, and application code.

PythonSQLDAXJavaScriptTypeScript

Analytics & reporting

Decision models, dashboards, workbooks, and KPI delivery.

Power BIExcel AutomationKPI Modeling

APIs & applications

Service layers, internal tools, and user-facing experiences.

FastAPIFlaskREST APIsNext.jsReactTailwind CSS

Data platforms & formats

Operational storage, structured exchange, and reporting-ready data.

Azure SQLPostgreSQLSQLiteJSONCSVParquet

Strengths

How I move work forward.

These are not proficiency percentages. They are the patterns that consistently show up across the systems I build.

End-to-End Problem Solving

Problem → production

From understanding the problem to deploying scalable solutions.

Manual Process to Automation

Manual → repeatable

Automating repetitive tasks to save time and reduce errors.

Operational Intelligence

Signals → action

Turning operational data into actionable insights.

Data Storytelling

Complexity → clarity

Clear visualizations and narratives that drive decisions.

Business Context

People + process

Solutions built with deep understanding of people and process.

Business domains

Where the systems create value.

The same engineering discipline is applied across operational environments with different data, users, and decisions.

Inventory

Stock visibility, reorder optimization, aging analysis, ABC classification.

Procurement

Vendor performance, PO tracking, spend analysis, cost optimization.

Automotive Parts

Catalogs, compatibility data, demand forecasting, returns and warranty.

E-commerce

Sales performance, customer insights, order analytics, conversion tracking.

Reporting Operations

Automated reports, scheduled deliveries, validation, audit compliance.

Profitability Analysis

Margin analysis, product profitability, customer profitability, scenarios.