I am presently a
Senior Firmware Engineer at Lunar Energy, developing home electrification systems.
Our end-to-end home energy ecosystem is made up of an integrated battery, inverter, solar panels and smart circuit
breaker platform. I lead firmware development for our System Central Controller, managing inverter functional safety,
power controls, voltage regulation and command orchestration.
Safety-Critical Systems & Certification
I implemented and witnessed critical safety modules that achieved functional safety certification for our inverter, including:
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Power-On-Self-Test (POST): ensures hardware integrity by detecting latent faults before the system enters
its operational state.
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Built-In-Self-Test (BIST): identifies hardware faults in real-time to ensure the system remains in
a functionally safe state during operation.
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Arc Fault Circuit Interrupter (AFCI): continuously analyzes electrical waveforms to detect hazardous arcing
signatures, automatically interrupting the circuit to prevent electrical fires.
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Residual Current Detection (RCD): instantly detects minute current imbalances between supply and return
conductors to provide high-speed isolation, preventing fatal electrocution and electrical fires.
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Ground Insulation Resistance Monitoring (GIRM): evaluates the integrity of insulation between PV electrical
conductors and earth, detecting isolation faults before they escalate into hazardous short circuits or shocks.
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PV/AC Relay Weld Detection Systems: monitors the physical state of contactors to ensure the
inverter can safely disconnect from the utility grid, preventing hazardous back-feeding and equipment damage
in the event of a hardware failure.
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Functional Safety State Machine: orchestrates the transition to a predefined safe state upon
the detection of a critical fault, ensuring the system maintains hardware integrity and user safety at all times.
These functional safety features enabled our first customer sale and site installation. Following its successful delivery
within my first
12 months, I was promoted to Senior Firmware Engineer (off-cycle). In this role,
I developed firmware features and robust development processes that supported the fleet's growth from 0 to over 1,300
production installations in 1.5 years, contributing to over 95% system uptime. I also secured a subsequent functional
safety certification for cost-down hardware revisions, in less than 3 months.
Systems Engineering & Product Compliance
I owned, architected and delivered features critical for compliance and market expansion. Each feature was delivered with
a turnaround of less than four months, enabling the company obtain regulatory approval and rapidly unlock new revenue streams.
My contributions included:
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PV Reverse Wiring Protection: Architected a robust PV bus management layer that passed
Sunrun’s
(America’s largest residential solar and storage installer) rigorous test suite with zero field issues,
ensuring a seamless rollout that eliminated hardware damage, warranty liabilities, and installation delays.
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Power Control Systems (PCS): Designed safety-critical bus bar overload control and power limiting
functionalities that achieved UL 1741 CRD certification, allowing for flexible system sizing without expensive main-panel
upgrades.
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Multi-string Arc Fault detection: Delivered high-fidelity sensing algorithms meeting UL 1699B
standards for up to 3 PV strings, critical for fire safety and regulatory approval in key expansion markets.
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AC Coupled PV integration: Engineered firmware-defined integration paths and interfaces
that enabled NEM 2.0 economics, maximizing ROI for homeowners and driving high attachment rates.
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Outage Watch: Developed and deployed a predictive backup feature that autonomously
managed energy reserves, maintaining power for 329 customers during the 2025 Christmas Eve grid
outage.
Fleet Reliability & Root Cause Analysis
To support our fleet as we scaled, I systematically diagnosed and resolved complex fleet stability issues that had plagued system
operation, including:
- CAN Communication Blackout: Eliminated fleet-wide communication blackouts by resolving a 49.7-day scheduler
overflow and architecting a GDB automation suite that reduced reproduction cycles from weeks to seconds, establishing
a new deterministic validation standard.
- AFCI Robustness: Developed custom web dashboards for fleet-wide observability, and eliminated false positive trips through
high-fidelity signal analysis and simulations. This data-driven approach to the AFCI challenge resulted in a robust algorithm that
was adopted as the production standard for the fleet.
- Stack Integrity: Resolved frequent watchdog resets by diagnosing RTOS thread stack overflows and cross-thread memory corruption
using TraceX. Implemented strict stack watermarking and automated handler to prevent illegal memory access and ensure deterministic
thread execution.
- Processor Brown-Outs: Diagnosed and eliminated intermittent relay chatter by developing standardized reset-reason
telemetry across all system ECUs, and implementing a voltage-compensated control loop that optimized the economizer logic
to maintain ideal holding currents while minimizing thermal losses and power consumption.
Development Infrastructure & CI/CD
Beyond feature delivery and fleet triage, I hardened the engineering lifecycle for the Subsystem Central Controller from
spec definition, to verification and validation. I also improved the ecosystem that builds the code, streamlining the
team's workflow:
- Implemented IAR compiler build scripts that save the team ~25 engineering hours weekly.
- Drove adoption of the Ceedling unit test framework across all 4 firmware core ECU components.
- Developed automated compiler errata detection tools based on
ast-grep,
Bash/ZSH and CI/CD.
- Established advanced debugging infrastructure using SEGGER Ozone, TraceX event tracing, and GDB scripting.
- Spearheaded effort to harden our firmware configurations by eliminating overloading on build types,
recognizing the importance of robust firmware binary configuration management in ensuring efficient
and reliable build processes for production readiness of all 7 real-time ECUs in our system.
Technical Leadership & Lifecycle Management
In addition to the work on development infrastructure, I have:
- Onboarded and mentored 3+ engineers, maintaining code quality standards for an additional 4 engineers.
- Served on the hiring committee assessing candidates from Intern to Staff level.
- Contributed to DFMEA efforts for next-generation products.
- Led cross-functional initiatives including the Subsystem Interface Specification that bridge Firmware and System teams.
- Led debrief sessions that standardized certification workflows across other ECU teams.
- Led a SEGGER Ozone debugging training for 15+ firmware engineers, elevating the broader team's collective skillset.
- Drove the cross-functional initiative to harden automated CAN code generation across 8 ECUs, authoring the requirements
specification document that guided the effort, with many others further contributing change requests to the documentation.
- Nurtured cross-functional relations, resolving critical dependencies across Hardware, Manufacturing, Software, and QA, such
as manufacturing yield issues and nightly regression tester support.
Tools: Full Stack Firmware Development (Hardware, Algorithms, Infrastructure, Leadership),
Static Analysis & Compiler Optimizations (AST-Grep), FPU, SDFM/DSD, Grafana, UL 1998/1699B/1741 CRD, Unity/Ceedling, Zsh, Google
Trace Build Time Profiler, Lauterbach, IAR, Infineon XMC4700, RTOS (ThreadX), ARM Cortex-M4, PlotJuggler Simulation Integration,
Low-level debugging (Ozone, TraceX, GDB, JTAG, ARM Assembly).
