Embedded Firmware Engineer – IoT, ESP32, C/C++

Freshers, Trainees and Experienced Engineers Welcome

Company: Smartomation.ai / DoorBox.ai

Location: Puzhuthivakkam, near Velachery, Chennai

Work Mode: Full-time, in-person

Experience: Fresh graduates through experienced firmware engineers

Openings: Multiple

Compensation: Based on experience, demonstrated skills and project capability

Build the Intelligence Inside DoorBox.ai

DoorBox.ai is looking for talented and highly motivated Embedded Firmware Engineers to help develop the next generation of our patented smart package-delivery platform.

DoorBox combines embedded systems, IoT connectivity, cameras, video processing, sensors, electronic-lock control, cloud communication, mobile applications and intelligent automation in one real-world product.

This is an opportunity to work directly on production firmware—not merely tutorials or isolated sample programs. You will analyze existing firmware, diagnose complex hardware/software problems, improve reliability and security, and help take the product from development boards through production deployment.

Learn more about the product at:

www.doorbox.ai

Who Can Apply

We welcome both:

Experienced Embedded Engineers

Engineers who can quickly understand an existing firmware codebase, debug hardware and software interactions, improve the architecture, and deliver reliable production firmware.

Fresh Graduates and Entry-Level Trainees

Recent graduates with strong fundamentals in electronics, embedded systems, C/C++, microcontrollers or IoT—and, most importantly, a serious interest in becoming excellent embedded engineers.

Freshers are not expected to know everything listed below. We are looking for candidates with sound fundamentals, curiosity, discipline, hands-on interest and the ability to learn rapidly.

The DoorBox Firmware Platform

The present firmware includes approximately 35,000 lines of code and targets a sophisticated dual-MCU architecture involving:

- ESP32-P4
- ESP32-C6
- ESP-IDF
- FreeRTOS
- Cameras and video encoding
- MIPI and USB interfaces
- Display and LVGL integration
- Wi-Fi and MQTT communication
- Secure over-the-air updates
- Sensors, locks and peripheral devices
- Power-management and sleep modes
- Cloud and mobile-app connectivity

Experience with the exact platform is valuable but not mandatory if you have strong embedded fundamentals and can learn quickly.

The 15 Firmware Competency Areas

The ideal candidate will have experience—or a strong interest in developing expertise—across these areas:

1. Embedded C and Modern C++

- Pointers, structures and low-level memory access
- volatile, bit manipulation and register-level programming
- Const-correctness, ownership and memory safety
- Modern C++ practices suitable for embedded systems
- Defensive programming and safe string handling
- Compile-time configuration and conditional compilation

2. MCU Architecture

- Clocks and clock trees
- Power domains
- Memory maps
- Reset behavior
- Interrupt architecture
- Multi-core and multi-MCU systems
- ESP32-P4 and ESP32-C6 architecture

3. Peripheral Drivers

- GPIO
- I²C
- I²S
- SPI
- UART
- USB
- V4L2
- SDMMC and SD cards
- MIPI and DSI
- Camera, display and sensor drivers

4. RTOS and Concurrency

- FreeRTOS tasks and scheduling
- Queues and event groups
- Mutexes and semaphores
- Interrupt service routines
- Race-condition analysis
- Priority inversion
- Task stack sizing
- Watchdogs and task supervision
- Thread-protected driver and UI interaction

5. Communication Protocols

- Wi-Fi
- MQTT
- TCP/IP
- TLS
- HTTP and HTTPS
- WebSocket communication
- Message reassembly
- QoS and reconnect behavior
- Cloud-to-device commands
- Device-to-cloud telemetry

6. Firmware Debugging

- Systematic root-cause analysis
- Hardware and software instrumentation
- Serial logs and trace analysis
- Crash dumps and backtraces
- Core dumps
- Watchdog and reset diagnosis
- Timing and performance measurements
- Reproducing intermittent defects
- Distinguishing symptoms from underlying causes

7. Hardware–Firmware Interaction

- Reading schematics and datasheets
- Pin configuration and multiplexing
- Voltage and power sequencing
- Sensor and actuator integration
- Electronic-lock control
- Camera and display interfaces
- Hardware bring-up
- Oscilloscope and logic-analyzer use
- Diagnosing electrical versus firmware problems

8. Bootloader and OTA

- Firmware partitions
- Bootloaders
- Secure over-the-air updates
- Rollback and recovery
- Interrupted-update handling
- Version management
- Image validation
- Production firmware deployment
- Field-device recovery planning

9. Power Management





- Light sleep and deep sleep
- Wake sources
- Power-domain control
- Battery-powered device optimization
- Current profiling
- Peripheral power gating
- Radio duty cycling
- Wake-up reliability
- Balancing performance and battery life

10. Memory Management

- Internal RAM and PSRAM
- DMA-capable memory
- Static and dynamic allocation
- Fragmentation
- Buffer ownership
- Lifetime management
- Use-after-free prevention
- Queue and pool design
- Stack and heap monitoring
- Memory-constrained video processing

11. Multimedia Firmware

- Camera capture
- H.264 video encoding
- MP4 recording and muxing
- MIPI camera interfaces
- Audio/video synchronization
- USB/UVC cameras
- Frame buffers and pipelines
- SD-card recording
- LVGL displays and user interfaces
- Video streaming and playback

12. Firmware Architecture

- Modular firmware design
- Layering and clear interfaces
- Module boundaries
- State machines
- Dependency management
- Separation of hardware and business logic
- Maintainable production architecture
- Refactoring large legacy modules
- Designing for testability

13. Git and Development Practices

- Git and GitHub
- Meaningful commits
- Branching and code reviews
- Repository organization
- Build reproducibility
- Dependency management
- Technical documentation
- Versioning and release tags
- Changelogs
- Continuous integration

14. Firmware Testing

- Unit testing
- Integration testing
- Host-based firmware testing
- Hardware-in-the-loop testing
- Regression testing
- Fault injection
- Mutation testing
- Boundary and negative testing
- Automated build verification
- Hardware test plans and evidence capture

15. Embedded Security

- Secure boot
- Signed firmware
- Flash encryption
- TLS and certificate validation
- Secure credential storage
- MQTT authentication
- OTA security
- Input validation
- Constant-time comparison
- Production debug-port control
- Threat identification and secure recovery

What You Will Do

Depending on your experience, you will:

- Understand and improve an existing ESP-IDF firmware codebase.
- Develop new firmware modules using C and modern embedded C++.
- Debug complex problems across firmware, electronics and cloud communication.
- Work with ESP32-P4, ESP32-C6 and FreeRTOS.
- Integrate cameras, displays, sensors, storage and electronic locks.
- Improve video capture, encoding, recording and streaming pipelines.
- Optimize power consumption and battery performance.
- Implement reliable Wi-Fi, MQTT, HTTP and cloud communication.
- Strengthen secure boot, OTA, credential management and device security.
- Create unit, integration and hardware-in-the-loop tests.
- Analyze logs, crash dumps, timing measurements and hardware behavior.
- Conduct firmware code reviews and document technical decisions.
- Use Git properly for branches, releases and traceable development.
- Build proof-of-concept solutions and convert successful concepts into production firmware.
- Work closely with hardware, mobile-app, cloud and product teams.

AI-Assisted Firmware Development

DoorBox.ai encourages responsible use of modern AI development tools to accelerate learning, debugging, code review, testing and documentation.

Based on approved learning and project requirements, the company may provide access to:

- GitHub Copilot
- Claude and Claude Code
- ChatGPT and OpenAI Codex
- Google Gemini
- AI API credits
- Selected Udemy embedded and AI courses
- Cloud and development resources
- Structured technical guidance

These tools should complement—not replace—sound engineering judgment, careful testing and hardware validation.

What We Value

We are looking for people who:

- Enjoy understanding how hardware and firmware work together
- Can investigate difficult problems patiently
- Verify behavior through testing and measurement
- Write clean, safe and maintainable code
- Are eager to learn modern embedded C and C++
- Take ownership of assigned problems
- Document their work clearly
- Accept technical feedback positively
- Use AI tools productively and responsibly
- Want to build a real product with global potential
- Can work consistently from our Chennai office

Qualifications

Preferred educational backgrounds include:

- Electronics and Communication Engineering




- Electrical and Electronics Engineering
- Computer Science Engineering
- Instrumentation Engineering
- Embedded Systems
- Mechatronics
- Robotics
- Internet of Things
- Other closely related engineering disciplines

Strong self-taught candidates with demonstrable embedded projects are also welcome.

Helpful—but Not Mandatory—Experience

- ESP32 or other microcontrollers
- ESP-IDF
- FreeRTOS
- Embedded C or C++
- Arduino, STM32, ARM or similar platforms
- Camera or video firmware
- IoT communication
- MQTT, HTTP or TLS
- PCB bring-up and debugging
- Oscilloscopes or logic analyzers
- Git and GitHub
- Unit testing
- Linux development environments
- Python-based test automation

Selection Process

Candidates may be asked to participate in:

1. An initial technical discussion
2. Review of academic, personal or professional projects
3. A practical C/C++ or firmware assessment
4. A debugging or code-understanding exercise
5. A small proof-of-concept assignment
6. An in-person discussion at our Chennai office

Freshers will be evaluated primarily on fundamentals, learning ability, commitment and hands-on potential. Experienced candidates will be evaluated on technical depth, previous products, debugging ability, architecture knowledge and independent delivery.

Salary and Career Opportunity

Salary will be determined based on:

- Relevant firmware experience
- C and C++ proficiency
- Microcontroller and RTOS knowledge
- Hardware-debugging capability
- Complexity of previously completed projects
- Ability to work independently
- Interview and practical-assessment performance
- Leadership capability, where applicable

Freshers may be considered for an entry-level trainee pathway with structured learning and practical assignments. Experienced candidates may be considered for Engineer, Senior Engineer or Technical Lead responsibilities based on their capabilities.

The exact role, trainee structure and compensation will be discussed transparently with shortlisted candidates before joining.

Chennai Office

Smartomation.ai / DoorBox.ai – GKB Building

5096, 7th Street

Ram Nagar North Extension

Puzhuthivakkam

Chennai – 600091

Near Velachery, Chennai

Google Maps:

https://maps.app.goo.gl/aqFptvwqUJfkmhNY7

Smartomation.ai is headquartered in the United States and operates its development office in Chennai.

Websites:

www.doorbox.ai

www.smartomation.ai

How to Apply

Please email your résumé in PDF format to:

[HIDDEN TEXT]

Email subject:

Embedded Firmware Engineer – [Your Name]

Please include concise answers to the following questions:

1. Are you an experienced professional, fresher, final-year student or self-taught developer
2. What is your degree, specialization, college and year of graduation
3. Are you currently employed, studying or immediately available
4. How many years of embedded firmware development experience do you have
5. How would you rate your Embedded C proficiency on a scale of 1–10
6. How would you rate your C++ proficiency on a scale of 1–10
7. Which microcontrollers and development platforms have you used
8. Have you worked with ESP32, ESP-IDF or FreeRTOS Please explain briefly.
9. Which of the 15 competency areas listed above are your strongest
10. Which areas would you most like to develop
11. Describe the most difficult firmware or hardware problem you have debugged.
12. What sensors, cameras, displays, communication modules or other peripherals have you integrated
13. Have you worked with Wi-Fi, MQTT, HTTP, TLS, OTA or cloud-connected devices
14. What experience do you have with oscilloscopes, logic analyzers, serial logs, JTAG or other debugging tools
15. Please provide links to your GitHub profile, portfolio, project videos or technical work, if available.
16. Have you used AI coding tools such as GitHub Copilot, Claude Code, ChatGPT or Codex
17. Can you work full-time from our Chennai office
18. Approximately how many kilometers away do you live from our Puzhuthivakkam office
19. Will you commute by public transportation or private vehicle
20. If relocation is necessary, are you willing to stay in nearby PG accommodation
21. How soon can you join
22. What is your current compensation, if applicable
23. What is your expected monthly compensation
24. On a scale of 1–10, how committed are you to building expertise in embedded firmware
25. Are you willing to complete a practical firmware or debugging assignment during the selection process

If you are passionate about embedded engineering and want to work on firmware that connects cameras, sensors, locks, wireless communication, cloud services and intelligent applications, we would be pleased to hear from you.

📌 Embedded Firmware Engineer (Chennai)
🏢 DoorBox
📍 Chennai