Scientific Software Engineer

Klima is an early-stage, science-driven start-up dedicated to reducing the climate impact of aviation. We develop an advanced software that helps airlines optimize flight trajectories both economically and climatically. Our work is built on close collaboration with key academic and industry partners, including airlines, manufacturers, airports, and air traffic control, to deliver practical and actionable solutions for a more sustainable aviation.

Mission

As a Scientific Software Engineer, you will play a key role in advancing our mission by mainly developing and maintaining our Python-based software. This ranges from architectural and algorithmic improvements to the codebase, to the development of new functionalities and the deployment of the software.

Your tasks include:

• Developing robust workflows (eg weather data provision) and REST API to access the results of the modelling chain
• Deploying our systems on the cloud with client-specific features
• Expanding our suite of physical models, for instance by testing new aircraft performance or climate impact models
• Reviewing and adapting the software architecture to handle growing workloads
• Assessing and improving computational efficiency throughout the software suite
• Implementing and benchmarking low-level existing and new optimisation algorithms

As the company grows, you will have opportunities to broaden your scope, contribute to strategic initiatives, and take on managing responsibilities.

Required Skills

We are looking for a candidate who combines strong modelling expertise with solid software engineering skills to further develop our models while maintaining high coding standards and robust software practices.

• Strong command of Python and scientific packages (eg xarray, dask, numpy, scipy)
• Good algorithmic skills, with the ability to design, analyse, and implement efficient algorithms and data structures
• Experience with code optimisation and performance tuning (profiling, vectorisation, parallelisation, and algorithmic optimisation)
• Autonomy, agility, and ability to work effectively in a collaborative team environment
• Technical English proficiency
• Experience working with weather and climate data and/or in the aviation sector
• Experience with containerization and orchestration

The role requires a curious, versatile candidate who enjoys learning beyond their core expertise. We welcome applications from skilled junior candidates who demonstrate scientific curiosity, motivation, and a strong desire to make a meaningful impact. Do not hesitate to apply even if you don’t meet all requirements.

Additional Information

Contract Type: Permanent/Full time

Start Date: September 2026

Location: Paris 6th

Salary: Starting at 42 k€ gross per year, according to profile and experience

Office-based work with occasional remote work possible once fully onboarded