Senior Software Engineer (Fullstack, Remote)

Haven Energy•Brooklyn, NY

1d•Remote

About The Position

Haven is seeking a Senior Software Engineer to join our small but mighty engineering team. You'll work across our stack alongside product, design, and data teams, building new capabilities and fortifying existing ones. We are building a new category of business in the home electrification space and firmly believe that our success and differentiation will depend on our ability to build software that provides a clean, simple interface on top of a complicated web of physical devices, data sources, and 3rd-party APIs. The electrical grid is complicated; our software's job is to make it seem simple. We want someone with an entrepreneurial mind who'll think critically about the business as a whole and participate in product- as well as technical-strategy. The ideal candidate excels at quickly building MVP implementations that can scale into more complete solutions, and can seamlessly pivot between driving execution and providing technical leadership as we grow the team. We want someone excited to shape culture and process as we navigate the growth stage of this business. This is a great fit for someone who's proven their abilities as a software engineer in a startup environment and is ready for their next step forward in ownership and impact.

Requirements

6+ years building software professionally, including web development.
Led technical design for non-trivial features shipped to production.
Built and maintained test suites.
Know your way around git and have done many code reviews on GitLab or GitHub.
Excellent written and verbal communication.
Enjoy interfacing with internal stakeholders and translating fuzzy business problems into clean software.
Used AWS or another major cloud provider in a real production capacity.
Excited about the climate tech space and building a more flexible grid while providing energy independence to customers.
Fluent in AI-native / agent-assisted development environments and have opinions about how to make them better.

Nice To Haves

Experience at early-stage startups.
Experience with some of the following: TypeScript, React/Next.js, Node.js on AWS Lambda (Serverless Framework), Python/Django, Prisma, Postgres, SQS/event-driven systems, dbt/Snowflake, monorepos (Yarn workspaces).
Integrated SaaS products with custom-built software.
Experience gathering and defining requirements for software features.
Industry-specific experience in residential solar, energy storage, home electrification, or other areas related to clean energy.

Responsibilities

Build and evolve customer- and partner-facing applications — including our marketing site, homeowner portal, and internal sales and ops tools — and the deal/lifecycle workflows behind them.
Collaborate with other engineers to build, from the ground up, the platform that operates our fleet of deployed batteries as a VPP.
Build installation software that allows our internal ops team and external installers to track and update the progress of battery installation projects.
Deliver technology that is tested, monitored, ready for scale, and trustworthy enough to operate on real customer money and legally binding documents.
Break down ambiguous, large projects into a sequenced plan and executable tickets, then drive them to completion.
Continuously raise the standard for readability, scalability, and security of our code.
Work cross-functionally with product, marketing, ops, and others to gather requirements and validate solutions.
Design and maintain robust integrations with third-party APIs and webhooks (HubSpot, DocuSign, QuickBooks, Stripe, Aurora, CompanyCam, and others), including idempotency, retry, and observability patterns for SQS-based async workflows.
Share ownership of CI/CD pipelines (GitLab CI), Lambda/Vercel deploys, and observability/alerting (Sentry).
Work AI-natively: agent-assisted development, MCP servers, custom skills and rules, and LLM-powered internal tools. We expect senior engineers to be opinionated about this workflow and help us push it forward.