Software Engineer - Senior

FACTOR; Greater London; On-site; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Private medical insurance

Life and income protection

24 days annual leave

Enhanced parental leave

Learning and development opportunities

Flexible working hours

Job summary

Factor is an API driven, AI powered retail data platform for global energy utilities. We build scalable data pipelines, pricing engines, and real-time APIs to support energy retailers and their customers.

As a senior engineer, you will own the core system with ownership, curiosity, and engineering excellence in a fast-moving team with remote-friendly practices. We offer flexible hours and remote-work opportunities, a competitive salary, private medical insurance, life and income protection, and

Qualifications

• Proficiency in Node.js, Python and PostgreSQL.
• Experience designing scalable data pipelines and APIs.
• Energy sector experience or data-heavy domains preferred.

Responsibilities

• Build and ship backend features and services with scalability and performance.
• Design core data architecture and APIs.
• Solve end-to-end data ingestion and transformation problems.
• Apply AI tools to accelerate development.
• Contribute to engineering standards and peer reviews.

Skills

Node.js

Python

PostgreSQL

AWS

Serverless

Tools

Node.js

Python

PostgreSQL

AWS

Serverless

Job description

Software Engineer - Senior

Department: Factor

Employment Type: Permanent - Full Time

Location: London, UK

Description

Factor is an API driven, AI powered retail data platform for global energy utilities. We use deep machine learning to help energy retailers accurately value the energy they sell: improving margins, unlocking more competitive customer products, and driving lower carbon emissions. We believe that great environmental outcomes come from smarter commercial models, and we earn our clients’ loyalty by helping them do good and do well.

We are a small, senior team that moves fast by collaborating, not following rulebooks. Headquartered in New Zealand, we’re building a global business; working remotely, flexibly, and across time zones to support our partners and clients.

Factor was acquired by Gentrack Group Ltd in May 2026. We operate as a division inside the Group, collaborating with our Gentrack colleagues to win new business and support Group customers. We also sell Factor independently, integrating with other software in the energy ecosystem.

At Factor, we don’t just write code - we are building the commercialisation layer for the new energy economy. Our engineers shape the foundations of a platform designed to transform how energy is priced, forecast, and delivered globally.

As a senior engineer, you will play a pivotal role in developing the core of our system: scalable data pipelines, pricing engines, and APIs that support real time decision making for energy retailers and their customers. You’ll work in a highly capable senior engineering team, where ownership, curiosity, and engineering excellence are expected — and where AI tools are used daily to multiply impact and velocity.

Your Key Responsibilities

• Build and ship backend features and services with a focus on elegance, scalability, performance, and resilience.


• Design and evolve Factor’s core data and application architecture (Typescript rust, AWS, etc).


• Solve complex, end to end problems across the stack, from data ingestion and transformation, complex algorithms, through to APIs and partner integrations.


• Contribute to engineering standards, peer reviews, and design discussions that raise the technical bar.


• Use AI and automation to accelerate development cycles, testing, and deployment.


• Help shape a culture of technical excellence, collaboration, and high ownership.

What We’re Looking For:

• Proficiency in Node.js, Python, PostgreSQL, and modern cloud architecture (AWS, serverless).


• Track record of designing and maintaining clean, maintainable systems that handle complex data and business logic.


• Experience in the energy sector (or other data


• Comfortable working autonomously in a fast problems and proposing solutions. heavy, mission-- critical industries) is highly valued. moving startup environment; proactive in surfacing


• Thrives on responsibility and ownership, with a low ego, high collaboration style.


• Excited by the opportunity to apply your skills to one of the world’s biggest challenges: the energy transition.

What We Can Offer You

• Competitive salary


• Private medical insurance


• Life and income protection


• 24-days annual leave


• Enhanced parental leave


• Tailored learning and development opportunities


• Flexible working hours and remote-work opportunities