Senior Back-end JavaScript Developer

About Carbonhound
Carbonhound supports almost 300 companies to help them automate measurement and reduce their climate impact. We are one of the fastest growing, impactful companies in the space in Canada with a platform to drive change. Our partnerships with big five banks (e.g., RBC) and the largest manufacturing associations in the country allow us to influence customers across Canada and the US.

You will work directly with the leadership team to deliver meaningful value to our customers, your teammates, the climate, and the foundations of our technical platform. This role involves wearing many hats—contributing to product and architectural decisions, team culture, and critical code decisions across our system stack.

The Role
We’re looking for a Senior Backend JavaScript Developer to join our 10‑person team to drive profitable climate action and make a meaningful difference with the work we do.

Our tech stack is JavaScript: functional React, Node.js, Postgre

SQL, Docker, Google Cloud Platform, Anthropic. We look for someone with a proven track‑record of designing and developing mathematical‑focused software systems and infrastructure with significant data volume, processing, real‑time results, and security requirements (like those found in financial systems). These data systems are currently written in Node.js to support early team competency but are not limited to JavaScript or Node.js. This is a hybrid role in downtown Toronto that expects 4 days a week in office, with WFH Fridays.

How to Apply

When submitting for this role, please include a one‑paragraph cover letter describing something you have created and are proud of that is live (or was live) in a production environment, ideally showing off your skills related to this role.

Responsibilities

Key code contributor of our primary BE services (~70% coding: writing code, reviewing PRs, technical solutioning, etc.)

Design and develop data pipelines that manage inconsistent load volumes of sensitive/secure data.

Maintain and upgrade highly configurable, idempotent mathematical data‑processing systems, enforcing a high bar for accuracy and performance.

Create high‑accuracy, performant data retrieval systems on flexible inputs.

Ensure the user‑facing application is fast and comfortable to use through server‑side, aggregate, and query optimizations.

Improve observability and audibility for both internal and external stakeholders.

Support the customer team’s autonomy through thoughtful self‑serve solutions.

Implement and encourage code and patterns that focus on quality, scalability, security, accessibility, performance, and good coding practice.

Champion ownership of data management and processing systems, following financial system standards (security, idempotency, ledger, etc.).

Configure and maintain analytics collection systems and coordinate with our data team on reporting requirements.

Keep up‑to‑date with the mathematics behind carbon accounting.

Own and handle bugs as they come, raising the bar on system quality and developer experience.

Actively share opinions and engage in product & solutioning sessions.

Define, manage stakeholders, and execute on your own technical solutions.

Act as both mentor and mentee to grow together with the team.

Keep up to date with technology industry trends and share them with the team.

Preferred Skills

Motivated by designing and implementing systems that process complex data with accuracy, performance, real‑time results, and security.

Seeking the challenge of scaling technology for a complex, dynamic industry with rapidly advancing scientific and technological standards.

Thrilled by a logistics challenge and coding scalable, configurable, idempotent mathematical data pipelines.

Enjoys developing flexible and quick‑to‑work codebases.

Excited to try new patterns, languages, AI tooling, etc., to push boundaries.

Loves writing great queries and improving indexes in SQL (Postgres).

Has shipped production Node.js server code.

Experience with setting up, managing, and optimizing cloud‑based architecture (GCP, AWS, Azure).

Comfortable working in and reviewing code for functional React when needed.

Familiar with Redis or other aggregation…