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David A Mullins

Experience

Where I have worked, most recent first. Some of these ran concurrently, since I consulted while employed.

Data Engineer

Utility scale renewable energy EPC

  • Shipped automated ETL and an operator facing web app orchestrator. Scaled weekly coverage from 5 to 30+ projects, cut per project processing from half a day to seconds, and drove portfolio refresh to under 5 minutes (replaces a 50+ hour per week manual task).
  • Owned design and implementation end to end. Proposed the platform overhaul, secured executive approval, defined interfaces, dimensions, and run control, and drove adoption across PM, scheduling, QC/QA, finance, logistics, and field construction teams.
  • Built a PostgreSQL warehouse with dimensional models and SCD Type 2 for as of reporting and auditability.
  • Standardized S curves and quality metrics and modeled facts and dimensions with SCD Type 2 to enable as of reporting and auditability.
  • Integrated Procore and Oracle Primavera Cloud with idempotent connectors and backfills and automated SharePoint distribution and Power BI datasets for downstream analytics.
  • Added statistical QC and reconciliation across the pipeline, built verification with lineage that flags issues in near real time and speeds resolution.
  • Normalized Procore fields and forms into analytic dimensions, standardized enumerations, and cleaned inputs to improve joinability, search, and reporting from the original messy data structure.
  • Wrote pipeline logic with parameterized SQL helpers and simple SQL, implemented late arriving handling and restart safe tasks with manual overrides and rollback.
  • Instrumented jobs and services with metrics, logs, and alert thresholds and authored guardrails for restart safe operations and manual overrides, reducing MTTR and recovery time.
  • Delivered executive dashboards and billing threshold indicators tied to contract milestones, improving cash flow timing and visibility.
  • Bridged senior executives, PMs, schedulers, QC/QA, and field teams. Delivered audience specific dashboards and pipeline views that reduced review time and improved decision quality.
  • Partnered with PMs on project specific reporting and workflow automation, produced custom reporting for pre sales engagements and client discussions, and prepared datasets that enabled sales to craft competitive yet feasible proposals.
  • Authored a teaching style architecture and implementation proposal with block diagrams and interfaces to align leadership. COO: "First time in my career a presentation sent before a meeting answered every question."
  • TypeScript
  • Next.js
  • PostgreSQL
  • ETL
  • Dimensional modeling
  • SCD Type 2
  • Procore
  • Oracle Primavera Cloud
  • Power BI

Software Developer / Analyst

Climbing Wall Advisors / Strigid Scientific

  • Sole developer of multiple applications, including a multi page full stack web app for financial projections and analyses per GAAP that helped clients raise equity and plan operations. Evolved into RouteLoom at routeloom.com as a self service version of the internal model used for years.
  • Next.js and React with TypeScript on the front end with server components and form actions and custom hooks for responsive state with useReducer, useContext, and useState.
  • Authentication and authorization with JWT sessions. Session store and rate limiter on Redis and relational schema on Postgres with Prisma migrations and ORM.
  • Additional apps and business tools involving an API surface with GraphQL resolvers and REST endpoints plus Apollo Client for cache and queries and webhooks for integrations.
  • Built valuation models for small business clients with ARR above one million dollars and delivered DCF, NPV, and IRR analysis to support equity raises and operating plans.
  • Testing with React Testing Library and Cypress and continuous integration and delivery via GitHub Actions.
  • Visualization and UI with d3.js and custom SVG controls with CSS and Tailwind styling and debounced and buffered pipelines for responsive UX.
  • Validation with Zod on the server and client side guards with error propagation.
  • Infrastructure with Docker and Linux plus logging and metrics on P75, P95, and P99 across client and server and Stripe for subscription tiers.
  • TypeScript
  • Next.js
  • React
  • PostgreSQL
  • Prisma
  • Redis
  • GraphQL
  • d3.js
  • Zod
  • Cypress
  • Docker
  • Stripe

Full Stack Developer

SaaS startup, health club industry

  • Lead technical developer of a business intelligence dashboard, a single page application for the health club industry, from wireframes through deployment.
  • Worked with UI and UX designers in Adobe XD and Figma, built the proof of concept in React and TypeScript, and ran user experience sessions to tune the layout.
  • Drafted technical requirements for internal and external stakeholders and defined an architecture that let later features land without a redesign.
  • Front end on Next.js and React with TypeScript. Apollo Client for cache and API requests. Central state management built from useReducer, useContext, and useState.
  • Backend on Node.js and Express with GraphQL resolvers, REST endpoints, and webhooks. Redis for session data and request rate limiting, Postgres for relational data.
  • Integrated AWS services including automated email and object storage, and Stripe for tiered subscriptions purchased inside the app.
  • Deployed to Linux cloud servers in Docker containers. Gathered P75, P95, and P99 latencies between client and server and debugged intermittent high round trip times affecting some users on some servers.
  • Built data visualization with interactive HTML5 charts and custom React state management.
  • TypeScript
  • Next.js
  • React
  • Node.js
  • Express
  • GraphQL
  • Apollo
  • Redis
  • PostgreSQL
  • AWS
  • Docker
  • Stripe

Applications Engineer

Keysight Technologies

  • Technical pre sales role bridging customer workflows and factory capabilities in electronic test and measurement and delivering tailored lab solutions.
  • Built custom automation and applications to coordinate instruments, perform complex computations, and enable new end user functionality.
  • Delivered cutting edge demos and integrated prototype hardware and software in customer labs, driving adoption by fitting solutions into real workflows.
  • Translated pre release 3GPP RAN specs into lab ready requirements for customers.
  • Partnered with Qualcomm's Wi-Fi team in lab to verify standards compliance on new silicon and designs, authored test plans, executed measurements, and debugged issues.
  • Validated demod performance under controlled SNR and phase noise profiles and verified margin in chamber.
  • Validated 5G device network interoperability with VZW and AT&T using OTA emulators in near field direct, CATR, and large anechoic chambers including phased array setups while executing registration and handover flows across PHY, MAC, Layer 3, and Layer 4.
  • Worked on applications from 100 kHz to beyond 40 GHz including frequency hopping radar, mmWave 5G, sub 6 GHz cellular, Ku, Ka, other satellite bands, and a wide range of modulation schemes and protocols.
  • Combined instrumentation across vector network analyzers, spectrum analyzers, signal sources, scopes, and reference clocks to minimize EVM and maximize SNR for stimulus and response measurements in customer labs.
  • Implemented prototype hardware and software in customer laboratories, custom tailoring Keysight's solution into end user workflows.
  • Became the subject matter expert on multiple facets of wireless engineering domains.
  • Key technical contributor in joint 5G TF and 5G NR labs with major cellular chipset manufacturers, validating new products through to first to market delivery.
  • Awarded for outstanding contributions and support of 5G NR business at Qualcomm.
  • Consistently exceeded sales goals, never falling below 140 percent of quota during tenure and earning President's Club for FY18.
  • Delivered marketing and instructional seminars in more than 30 cities.
  • Developed software, test automation, scripting, and larger toolsets using JavaScript, MATLAB, LabVIEW, and C# depending on customer needs.
  • Received a testimonial from a Qualcomm senior director thanking Keysight leadership for creativity, endurance, and problem solving: "He is the go to guy for many people in lab."
  • 5G NR
  • 802.11
  • OTA
  • PHY / MAC / L3 / L4
  • mmWave
  • MATLAB
  • LabVIEW
  • C#
  • JavaScript

Systems Engineer

Symmetricom / Microsemi

  • Led technical execution across software, firmware, hardware, and mechanical from concept to delivery for defense and satellite customers and partnered with PMs on planning and status to keep milestones on track.
  • Worked alongside PhD metrologists in the labs at NIST on Allan deviation and long term timing stability characterization, the reference work behind the oscillator and atomic clock designs.
  • Designed and validated high stability timing solutions with on chip atomic clocks and achieved timing stability in the tens of picoseconds for embedded precision timing applications.
  • Performed RF propagation and link budget analyses for satellite communications and implemented and debugged receivers, transmitters, and custom protocol interfaces across FPGA and embedded systems.
  • Evaluated and integrated FPGA and DSP devices for receiver chains and coding features and profiled performance to guide device choice.
  • Ran short notice customer reviews and proof of concept demos, demonstrated progress to secure next phase funding, and kept programs on schedule.
  • Supported vibration and EMI and EMC testing and mitigations for radiation tolerant deployments.
  • Coordinated requirement capture, tasking, and triage and prepared materials for milestones and delivery while partnering with vendor engineering to reproduce failures and validate fixes.
  • Embedded
  • FPGA
  • DSP
  • Link budget
  • Satcom
  • Precision timing
  • EMI / EMC
  • Linux
  • CentOS
  • Fedora
  • Ubuntu

RF Engineer

Echostar

  • Specified, debugged, validated, and delivered satellite communications subsystems and conducted field studies including rain fade investigations and performance characterization.
  • Deployed extensive test automation in TCL, JavaScript, and LabVIEW and built custom RF fixtures, saving thousands of engineering hours and improving repeatability and coverage.
  • Investigated RFI and EMI in failing units.
  • Validated a cable modem design with an on site CMTS and Ixia traffic generation.
  • RF
  • Satcom
  • Test automation
  • TCL
  • LabVIEW
  • JavaScript

Research Assistant

Texas A&M University

  • Worked on Dr. Righetti research team developing algorithms for digital signal and image processing with a focus on biomedical imaging techniques.
  • DSP
  • Image processing
  • Biomedical imaging

Education

  • Master of Science, Electrical Engineering

    University of Colorado Boulder

  • Bachelor of Science, Electrical Engineering

    Texas A&M University