I’ll never forget my very first hire as a new manager.

It was a disaster.

For me and for the poor intern I hired.

It was a cold day in January 2011 in Berlin. I had just started as Head of Business Analytics at Rocket Internet, then the largest venture builder in the world. Rocket became famous for launching companies like Zalando, Delivery Hero, and HelloFresh.

This was my first-ever leadership role, and my mission was to build a data team to support dozens of new ventures worldwide.

My boss, who’d joined a few months before me, had hired the first couple of team members. But eventually, it was my turn to make my very first hire - on my own.

To keep the stakes low, I started with an intern to help us as a data analyst.

I was terrified.

• How do I decide who to invite for an interview?
• What should I ask?
• How do I compare candidates and make a decision?
• What if the candidate asks questions I can’t answer?
• How do I handle the pressure to fill the role fast?

In my first interview, I was probably 10× more nervous than the candidate.

And sure enough, I completely blew it.

I lost track of my questions and got caught off guard by a few of his.

Worse: the candidate I eventually chose turned out to be a terrible fit - both culturally and in terms of skills. After a few painful months, we parted ways.

I felt embarrassed and ashamed - and got into trouble with my boss more than once because of that hire.

The day I realized my mistake, I started writing a list of hiring principles. I’ve fine-tuned that list over the past 17 years. I wanted to make damn sure I never repeated that disaster. And - knock on wood - after hiring dozens of people at all seniority levels all over the world, it’s only happened one more time.

My Hiring Principles

For context: over my 17 years in data, I’ve mostly hired data analysts, data engineers, data scientists, and data leaders for fast-growing VC- or PE-backed consumer companies.

I believe my principles work universally, but you may need to adapt them to your specific situation.

Also, these reflect my personal values and beliefs. You might disagree with some of them - and that’s OK. My goal is to give you a framework you can build on, especially if you’re hiring for the first time.

Principle 1: Ignore Corporate Profiles

At Rocket Internet, I reviewed hundreds of CVs from people who had worked at big banks, telcos, or large IT consultancies their entire careers.

After a few rounds of interviews, I stopped inviting them altogether. None of them would have survived in a VC-backed company.

Do yourself and the candidate a favor: make sure there’s a strong culture fit from the start.

Principle 2: SQL is a MUST for all Positions

I run SQL tests - even for data leaders. Most VC-backed companies need hands-on leaders. Even when they don’t, I’ve found that strong SQL skills predict solid on-the-job performance.

I never ask theoretical questions. Instead, I use services like db-fiddle to prepare practical, real-life cases.

Principle 3: Case-Driven Interviews

I use standardized, real-world case challenges. I tweak them slightly based on the candidate’s experience and the role, but otherwise keep them consistent so I can compare candidates fairly.

Case studies are the best predictor of real-world performance.

I’ve never used brain teasers or puzzles, and never will. 🧠 (Seriously, who cares how many golf balls fit in an A380??)

Principle 4: Interview Process Length

I typically have candidates interview with:

• Me
• HR (for culture fit)
• At least one peer
• At least one stakeholder (for user-facing roles)
• One of the founders (depending on company size and maturity)

Yes, candidates often complain about long interview processes. But I believe it’s in their best interest to really get to know the company. Of course, turnaround time matters. The whole process should never take more than 2 weeks.

Principle 5: Pitch Truthfully

One of the biggest mistakes I see new managers make is assuming that the candidate is pitching to them. That’s only half true.

The less well-known your company, the more important it is to sell your team and vision to the candidate.

But don’t sugarcoat it. The last thing you want is surprises when the candidate joins.

Principle 6: Attitude Over Experience

Yes, some experience is necessary, but it’s never my main hiring criterion.

Much of my case interview is designed to test attitude, not just technical and intellectual ability.

There are two things I always look for:

1. Does the candidate show curiosity about the company’s business model?
2. Do they give up easily when pushed into unfamiliar territory?

Bottom Line

Hiring for the first time is nerve-wracking. And costly if you get it wrong.

I learned that the hard way.

But over 17 years, I’ve developed a set of proven principles that helped me avoid repeat disasters. Whether you’re a new manager or just want to sharpen your hiring game, these strategies can save you from painful mis-hires.

👉 Ready to level up your hiring? Start applying these principles today, or risk learning the hard way like I did.

P.S. In my masterclass "From Dashboard Factory to Strategic Partner" I teach all my Hiring and People Management Frameworks—plus many more strategies to create outsized business impact with your data team.