Software Engineer, Developer Infrastructure

Job Description

Job Description

Location: Redwood City, CA (Hybrid — 3 days/week in office)

The Mission

Our mission is to move humanity off of fossil fuel heating. 20% of US global warming emissions come from homes (that's more than cars!). The largest driver of home emissions is burning fossil fuels for heat. To stop climate change, over 80M US homes need to transition from combustion to efficient, electric heat pumps over the coming decades.

We believe for this to happen the world needs fantastic products that are easy to purchase. Today's heat pumps lack great design, make limited use of software, and are difficult and stressful to adopt. We are building a next generation, beautifully designed, AI optimized home heating and cooling system that is 10x better than what is on the market today.

The Problem

AI agents can generate code 100x faster than humans. But at Quilt, generating code was never the bottleneck, verifying it is. We build software that runs on physical hardware in people's homes. A bug isn't a broken pixel; it's a family without heat. Our code spans embedded C++ on custom devices, cloud infrastructure, and mobile apps. Right now, too much of our verification depends on a human walking to a test bench and pressing a button.

We need to build the factory that builds the code.

We're looking for a software engineer to own our developer infrastructure: the simulators, test harnesses, CI/CD pipelines, and verification systems that let our engineering team (and our AI agents) ship fast with confidence. Your work will directly determine how quickly Quilt can move: not by writing features, but by making every feature easier to build, test, and trust.

The Role

This is a high-leverage infrastructure role. You'll be the engineer who makes every other engineer on the team more productive. You'll build the systems that close the feedback loop between code generation and code verification, so that an engineer (or an agent) can write a change, get an automated signal on whether it works, and iterate without waiting on manual testing.

We already have hardware-in-the-loop test rigs and some device simulators in place. Your job is to expand them, make them robust, and build the scaffolding that lets the whole team write and run tests with minimal friction.

What You'll Do

Build the Verification Machine (50%)

You'll own the infrastructure that gives our team fast, reliable signals on whether their code works.

• Design and extend device simulators and mocks that reduce our dependency on physical hardware for testing
• Build and maintain CI/CD pipelines across embedded, cloud, and mobile (GitHub Actions, Bazel)
• Extend our hardware-in-the-loop (HIL) test infrastructure for device commissioning, OTA updates, and telemetry validation
• Automate the manual test scenarios that currently block releases (pairing flows, firmware upgrades, cloud integration)
• Debug and eliminate flaky tests, CI must be a source of truth, not noise

Make Testing Easy (35%)

The best test infrastructure is one that every engineer actually uses. You'll make it effortless to write and run tests.

• Build reusable test fixtures, libraries, and templates that lower the barrier for engineers to write unit and integration tests
• Design testable interfaces and mock layers for embedded device features
• Collaborate on architecture decisions to ensure new code is testable by default
• Provide patterns and examples (pytest, gtest) that engineers and agents can copy and adapt
• Improve the local development and CI experience so tests are fast and reliable
• Document testing patterns and best practices, especially for embedded systems

Strengthen Release Confidence (15%)

• Validate critical release paths with automated and exploratory testing (device pairing, OTA, mobile app integration)
• Support mobile app testing (iOS/Android) for key user flows
• Turn customer-reported issues into new automated test cases, closing gaps in the verification machine so the same bug never ships twice

What We're Looking For

We'd love to speak with you if:

• You have 4–7 years of software engineering experience, with significant time spent on test infrastructure, developer tooling, CI/CD systems, or platform/infrastructure engineering
• You're a strong Python developer (pytest preferred) and comfortable reading/modifying C++ test code (gtest)
• You've owned CI/CD pipelines end to end; not just maintained them, but designed them to be fast, reliable, and trusted
• You think about testability as an architecture problem, not just a coverage metric. You've influenced engineers to refactor code so it can be tested
• You're comfortable in Linux/Unix environments and can debug complex issues across hardware and software boundaries
• You care about developer experience: you notice when something is painful and you build the tool to fix it
• You can work independently, identify the highest-leverage infrastructure gaps, and make the case for fixing them
• You have experience with or interest in how AI agents can be integrated into testing and verification workflows

Bonus points for:

• Experience building or maintaining hardware-in-the-loop test systems, device simulators, or integration test environments for IoT or embedded products
• Experience with device communication protocols (Modbus, serial, gRPC)
• Experience testing firmware OTA updates or device provisioning flows
• Bazel build system experience
• Docker and containerization for test environments
• Mobile test automation (Appium for iOS/Android)
• Web E2E automation (Cypress/Playwright)
• HVAC, home automation, or similar IoT domain experience
• Embedded Linux or Raspberry Pi development

What Success Looks Like

In 3 months:

• You've automated the top 10 manual test scenarios that were blocking releases, enabling the team to ship more features with higher confidence
• CI pipeline improvements have cut test cycle time by 30%
• You've mapped the biggest testability gaps in the embedded codebase and have a plan to address them

In 6 months:

• Engineers are writing significantly more tests because you made it easy — new fixtures, better patterns, faster feedback
• Device simulator coverage has expanded to cover new product variants
• Regression suites are catching bugs before they reach manual QA

In 12 months:

• Engineers trust CI results over manual validation for the majority of changes
• You've led a major refactor to make a previously untestable subsystem fully testable
• You've been hard at work on building infrastructure that lets AI agents verify their own code changes, closing the loop between generation and verification
• The team is shipping faster and with higher confidence because of the systems you've built

Why This Role Matters

At Quilt, we support live products with real customers depending on us, we have the technical complexity of an established company with the resources of a startup, and AI is making code generation nearly free while verification remains expensive. The engineer in this role will be the single biggest lever for getting us out of that middle. You're not writing features; you're building the foundation that lets every feature ship.

If you've read about "harness engineering" or the idea that engineering leadership is shifting from writing code to building the systems that enable code to be written, tested, and shipped with confidence — that's this job. You can find more information about how we're thinking about this matter here.

About Quilt

We are a growing team of ambitious people who truly care about the impact of their work. We are on a mission to accelerate a species-level human transition. For over a million years, we've been burning things to stay warm. It's time to move to a better way of living.

At Quilt, we're on a mission to make clean, efficient heating and cooling accessible to everyone — and we know that heat pumps can play a big role in creating healthier, more climate-resilient homes. But the reality is, climate change and outdated energy systems don't impact everyone equally. That's why we're building a diverse, inclusive team — because we believe the best solutions come from people with different lived experiences and perspectives. We welcome teammates of all races, ethnicities, genders, identities, abilities, and backgrounds, and we're committed to creating a workplace where everyone feels empowered to shape the future of climate tech.

Need accommodations during the hiring process? No problem — just let us know. We're here to support you. (View email address on us.fitly.work)

Compensation

This is a full-time, hybrid position working out of our Redwood City office. Candidates must be able to commute to the office at least 3 days a week.

We are not able to offer relocation assistance for this role.

The expected base annual salary range for this role is $150,000–$200,000, depending on experience. In addition to base salary, Quilt also offers meaningful equity and top-tier health benefits.

Don't meet 100% of the requirements? That's okay, apply anyway! If you're excited about this role and think you could bring something unique to the team, we encourage you to apply, even if your experience doesn't match perfectly. We'd love to hear from you.