Discover the Weefin team

At WeeFin, our strength lies in our multidisciplinary team of over 100 passionate collaborators who combine technical expertise with deep knowledge of sustainable finance. Discover the faces and journeys that make WeeFin a reference player in the digital transformation of sustainable finance.

The co-founders

Grégoire Hug

Co-founder & Chief Executive Officier

Grégoire Hug is a French entrepreneur, CEO, and co-founder of the company WeeFin. He holds a master's degree in econometrics and quantitative economics from Aix-Marseille University, as well as a master's degree in applied mathematics from Ecole Centrale Marseille. Grégoire began his professional career in 2011 at BNP Paribas Securities Services as an analyst in the Risk and Performance department before becoming the head of the same department in 2016.

In 2018, he embarked on an entrepreneurial adventure and founded WeeFin, a fintech company with the ambition to make sustainable finance more demanding and ambitious. Additionally, Grégoire is responsible for the Portfolio Management course at Ecole Centrale Marseille and teaches Sustainable Finance at Aix-Marseille University.

Guillaume Klech

Co-founder & Chief Technology Officer

Guillaume Klech is one of the co-founders of Weefin and the company's CTO. An engineer by training, he has nearly 20 years of experience, gained in both large industrial groups and the finance sector.

At WeeFin, he leads a technical team whose challenge is to continuously develop our platform so that it can handle growing volumes of data and offer new features that meet our customers' needs, without compromising on security, reliability and availability.

Marion Aubert

Co-founder & Chief International Officer

Passionate about innovation and sustainability, Marion is dedicated to driving impact at the crossroads of finance, technology, and responsible investing.

She co-founded WeeFin to help financial institutions integrate ESG and sustainable finance through advanced software solutions. Leading the company’s international growth, she focuses on expanding into the UK market.A key force behind the platform’s development and scale-up, she ensures it delivers strong value to clients.

Alongside her operational role, she sits on the Board and Executive Committee, shaping the company’s strategy and governance.In 2025, she was recognized in Forbes 30 Under 30.

Corporate governance

Julie Truong

Head of Human Resources

Julie Truong joined Weefin as Head of Human Resources in 2022, after working for WWF as HR Manager. She is the driving force behind a positive internal culture and an ambitious employer brand.

Her expertise helped support the company's exponential growth, which has quadrupled its workforce since her arrival (now more than 100 employees).

Laura Aich

Chief Operating Officer

Laura Aich graduated from ESG Management School in Paris. She began her career at Edmond de Rothschild as a Middle Officer, before moving on to roles at Natixis Asset Management, Schelcher Prince Gestion, and Meeschaert Amilton AM, where she specialized in process optimization, operational structuring, and organizational transformation.

In 2022, she joined WeeFin as Chief Operating Officer (COO) and member of the Executive Committee, with responsibility for overseeing all operations, structuring growth, and supporting clients.

Matthias Breier

Chief Product Officer

Before joining WeeFin in July 2025, Matthias Breier worked as ESG Product Manager at CSSP, an ESG reporting company based in Liechtenstein. He then became Product Director, responsible for regulatory reporting at FE fundinfo, a European financial data provider.

He holds a PhD in Business Model Innovation from the University of Lappeenranta in Finland.