Lead Engineer

TransitionZero; Greater London; Hybrid; GBP 110.000 - 170.000; Vollzeit

Benefits dieser Stelle

Pension auto-enrolment

25 days annual leave

Remote work 20 days/year for anywhere

Hybrid working

Home office budget

Training budget

Parental leave (16 weeks)

Private healthcare

Zusammenfassung

TransitionZero, a climate-tech non-profit, seeks an experienced Lead Engineer (back-end) in London to lead the team building the Scenario Builder backend. You will line-manage 3–5 engineers while contributing as a senior IC, shaping architectural decisions and API design.

You will work closely with product, data engineering and modelling teams to deliver scalable, secure back-end services. Hybrid work from our London office near Waterloo Station.

Qualifikationen

• 7+ years of experience in back-end software development.
• Strong proficiency in Python and RESTful APIs.
• Experience with databases (PostgreSQL, Redis, Firestore) and data modelling.
• Experience with cloud platforms (GCP) and containers (Docker).
• Familiarity with AGILE/Scrum processes and code review practices.
• Experience mentoring engineers and leading technical discussions.
• Understanding of OAuth and web security best practices.
• Experience with infrastructure-as-code tools such as Terraform/Terragrunt and GitOps.

Aufgaben

• Design, develop, and maintain scalable back-end services and APIs using Python and FastAPI.
• Build high-performance API endpoints for complex data queries and aggregations.
• Ensure reliability, performance, and security through testing and monitoring.
• Collaborate with front-end engineers and data/modeling teams on API design.
• Lead architectural planning, ADRs, planning, and code quality reviews.
• Line-manage a small team, run 1:1s, and support career development.
• Oversee cloud infrastructure (GCP) and CI/CD pipelines.
• Maintain IaC, scripting, and security best practices.

Kenntnisse

Python

REST APIs

Data modelling

PostgreSQL

Redis

Cloud (GCP)

Docker

AGILE/Scrum

OAuth / Web security

Terraform / Terragrunt

GitOps

Generative AI / LLMs

Tools

Docker

Terraform

Terragrunt

PostgreSQL

Jobbeschreibung

You should have a long-term commitment to advancing the energy transition and be driven to build robust, scalable systems that power our grid modelling platform. Passionate about creating highly performant back-end services, you understand the technical challenges associated with building niche B2B products that handle complex computational workloads.

In addition to seeking out people with a proactive, problem-solving attitude and an eye for detail, as a growing organisation, collegiality and empathy for our coworkers are a requisite. While we are a rapidly growing tech startup, we are also a non-profit, so a high level of adaptability and willingness to approach challenges with creativity and curiosity is essential.

About the role

We are looking for an experienced Lead Engineer (back-end) to lead the team in building and scaling the infrastructure behind Scenario Builder, our electricity grid modelling platform.

You will line-manage a small team of engineers while remaining a highly active individual contributor. You will own the technical shape of engineering work on the back-end team - leading planning, architecture, and code quality. You will work closely with the wider product and engineering team to design, develop, and maintain the back-end services that power our platform.

This hybrid role is based out of our London office near Waterloo Station and reports to the Head of Platform.

Responsibilities

Back-end development & architecture

• Design, develop, and maintain scalable back-end services and APIs using Python and modern frameworks (FastAPI).
• Design and build high-performance API endpoints to handle complex hierarchical data queries and multi-dimensional aggregations for grid modelling computations.
• Ensure system reliability, performance, and security through best practices in code quality, testing, and monitoring.
• Collaborate with front-end engineers to design and implement RESTful APIs that support our web application.
• Collaborate with data engineers and domain experts on the evolving core data model.

Infrastructure & DevOps

• Manage and optimise cloud infrastructure (GCP) to support our computational workloads.
• Implement and maintain CI/CD pipelines to enable rapid, reliable deployments.
• Monitor system health and performance, proactively identifying and resolving issues.
• Implement and maintain infrastructure-as-code.

Technical leadership & collaboration

• Participate and lead in code reviews, architectural discussions, and technical planning sessions.
• Own technical planning: break down roadmap items into well-scoped engineering work, lead estimation, and drive architectural decision records (ADRs).
• Collaborate with cross-functional teams, including product, data engineering, and modelling, to deliver impactful features.
• Set and uphold the team's technical standards — code quality, testing strategy, API design — through direct example and code review.

People & line management

• Line-manage a team of 3–5 engineers: run regular 1:1s, support career development, and provide timely, constructive feedback.
• Partner with the Head of Platform on performance reviews and personal development plans.
• Act as the first point of escalation for day-to-day technical blockers

Skills and experience

• 7+ years of experience in back-end software development, with strong proficiency in Python.
• Experience designing and building RESTful APIs and microservices architectures.
• Strong understanding of database technologies (PostgreSQL, Redis, Firestore), ORMs and data modelling principles.
• Experience with cloud platforms (preferably GCP) and containerisation technologies (Docker).
• Solid understanding of software engineering best practices, including testing, code review, and documentation.
• Excellent problem-solving skills and ability to work independently on complex technical challenges.
• Experience line managing or formally mentoring engineers, with confidence running 1:1s and supporting career development.
• Understanding of OAuth and web security best practices.
• Experience with AGILE/Scrum based ways-of-working
• Experience in the energy sector or with computational modelling/simulation software.
• Familiarity with scientific computing libraries (NumPy, Pandas) and optimisation frameworks.
• Experience with generative AI/LLMs in applied engineering contexts
• Experience with infrastructure-as-code tools (Terraform, Terragrunt) and GitOps practices.

About us

TransitionZero is a climate tech non-profit founded in 2021. TransitionZero builds software to reduce the time to build clean energy at scale. We pioneer open access and open source tools that make electricity system modelling more transparent, accessible, and actionable for governments, financiers and grid operators worldwide.

Our flagship tool, Scenario Builder, enables policymakers, planners and investors to rapidly build, analyse and share energy system and electricity grid models without coding expertise or external consultants. Supported by model-ready datasets, training and market insights, our tools strengthen in-house capacity and support resilient, affordable and locally-led energy transitions.

At TransitionZero, we understand that diversity is an essential component of a successful team, whether that be diverse ways of thinking, personal or professional backgrounds, or skills. We aim to be the most talented non-profit in our vertical through our culture of ownership and adaptability.

• Enhanced competitive pension scheme - auto-enrollment from day 1
• 25 days annual leave (excluding UK public holidays) and an additional discretionary days off such as over the festive period
• 20 days of annual allowance to work from anywhere in the world
• Hybrid working and core working hours model
• Annual allowance to set up your home office
• Annual budget and dedicated leave time for relevant training courses
• Enhanced gender-neutral parental leave (16 weeks fully paid)
• Private healthcare following the successful completion of the probation period