Founders Story: Sifflet

EQT Ventures
Published in
6 min readApr 18, 2024

Real-life frustrations with data helped Sifflet’s three co-founders change the paradigm towards trustworthy data

Wissem Fathallah, Co-Founder & Chief Product Officer, Salma Bakouk, CEO & Co-Founder and Wajdi Fathalla, CTO & Co-Founder

Founding teams are brought together under a variety of circumstances — many of which are happenstance.

But the three people behind Sifflet, the company behind the world’s first full data stack observability platform, are united by a different shared bond. Sheer determination born from frustration. “One common thing in our story is our drive and ambition to build one of the biggest software companies in the world,” says Wissem Fathallah, who set up the company in 2021 with his brother Wajdi and co-founder Salma Bakouk.

The three co-founders come from vastly different working backgrounds. Bakouk, Sifflet’s CEO, was an executive director at Goldman Sachs in Hong Kong between 2015 and 2020. Wajdi Fathallah, the CTO, had founded a consulting firm specializing in data engineering in Paris called Valuraise, and was working on its clients’ data and cloud architectures. And Wissem Fathallah, now CPO, was overseeing marketplace analytics at Uber Eats, after a Data Science role at Amazon.

But while they were working at very different companies, they had a shared pain point. “It doesn’t matter how much money and resources you invest in having the most up-to-date technology and the most sophisticated solutions,” says Bakouk. “I realised that something was missing.” At the time, building algorithms for training and then selling them to clients, she struggled to explain what exactly this missing piece was. That was until she met up with her old university friend, Wissem, and his brother Wajdi, and they landed on the answer.

“We needed something that could speak to the data producer and the data consumer, what today we call data observability. It’s about ensuring that these two people can communicate and can build a robust framework around data reliability,” says Bakouk.

The problem was simple: before Sifflet you couldn’t always trust the reliability of your data. Engineers had built data quality monitoring frameworks, but they weren’t easily understood by those on the frontline of businesses, dealing with the data day in, day out. Data producers and data consumers would talk at cross purposes.

It was something that Wissem saw in his past roles. Business users would complain that their data was not correct, and existing software on the market couldn’t fix it.

“The fact that the three of us experienced the problem before Sifflet is really key,” says Wajdi, “because basically we’re building something to solve our own issues.” They’ve walked that path before, and come up against the same roadblocks. So they know how to design a solution that overcomes them. Or as Wissem puts it, “I’m a firm believer that like everything, we can always do better. We can always think outside of the box; we can always bring innovative ideas to maybe tackle the same problems in a better manner, more efficiently, at a higher scale, at lower costs.”

Sifflet is simple, says Bakouk. “It’s a platform that does monitoring end-to-end and bridges the gap between the data producer and the direct consumer,” she explains. “It allows each one of them to create monitors in our data quality rules in the most frictionless way, to adopt monitoring as a practice.” Assured of data quality, and not having to second guess its reliability, businesses can get on with growing. The setup process is simple and deliberately so, so that people across a business — some of whom won’t have technical knowledge — can use it. It also provides ongoing monitoring of data issues, creating actionable insights for end users to act on problems before they promulgate.

Data entropy was the issue Sifflet sought to solve. But it took some time — and confidence — from coming up with the concept to launching the business. Bakouk quit her job in Hong Kong and moved into her parent’s home, back into her teenage bedroom. She’d spend every day during covid lockdowns talking on Zoom to the Fathallah brothers, before they decided to move into an eight square-metre office in Paris. Most founders would be daunted, but the trio were confident. “When you give up a job and just shift your mentality where success is your only target, that’s the only choice you have,” says Wajdi. “You put yourself in this kind of mindset, then every small step you take will take you towards success.”

The co-founders seek to battle entropy in all its facets — not just data. One of their key company values is a three-word principle: “bias for action.” Time is a startup’s most valuable resource, explains Bakouk — and it’s also the most scarce resource for stretched founding teams. But doing, rather than thinking, is the way to get things done according to the Sifflet team.

That extended to the product’s launch. One day in March 2022 the trio sat down in their office, says Wajdi, and decided: “Enough building, let’s see how the product is perceived.”

“There are so many other builders, companies that try to find the perfect solution, but they lose so much time and also do not get enough feedback to steer the product to work in the right direction,” he says. “Going to market as early as possible was crucial for us, because despite the products being very complex and very hard to build, we needed to experiment,” says Bakouk. “We needed to be close to the end user to make sure that we were building a viable product.” Those early users helped reinforce the initial vision and encouraged Sifflet to grow.

Such growth brought it in front of the eyes of EQT Ventures, and partner Carl Svantesson in the summer of 2022. “You meet a couple hundred founders per year, but this was something extra,” says Svantesson. “They had a very opinionated, clear reason for why they existed, and why they were the best team to do this.” EQT Ventures was impressed by their credible founder path to get to where they were — and the fact they had lived the challenges they sought to solve convinced the team further.

Every time they met over the next few months, Svantesson was told what the short-term plans for the future of the business were. And each time they reconvened, those goals had been achieved. “Every time they told me what they were going to do, every time they came back, they had done it,” he says. It helped solidify confidence that their core principle of “bias for action” weren’t just warm words. They were a lived sentiment.

EQT Ventures backed a Series A investment into Sifflet, which was announced in March 2023. It was a competitive process, the co-founders admit, but they chose EQT Ventures because they drove the whole process, and built up a trusting, supportive relationship with Svantesson.

In just three years since its founding, Sifflet has grown enormously. The three co-founders have become a team of 60, supported by Svantesson and EQT Ventures to help understand how to turn a small team into a bigger one (Bakouk calls Svantesson “almost like a part-time CRO or part-time CFO”). “We had some fantastic stories last year where folks grew adoption by 10x in six months and things like that,” says Bakouk. But they don’t want to stop there. And that’s when another shared vision and value comes into play.

Shared values are vital, says Bakouk — and are something that the three co-founders of Sifflet have in spades. “It’s very important that founders align on a certain set of values,” she says “We have that, and I think that’s what keeps us going. That’s what keeps us motivated and ambitious. The three of us are extremely ambitious people.”