Jan Hammer focuses on startups that rebuild the core infrastructure of finance and data rather than just front-end experiences, backing companies like Adyen, Collibra, Wise and Robinhood that operate at the deepest layers of the digital economy's transaction and data flows. He champions full-stack models in fintech, using Adyen as an example of one company rebuilding merchant acquiring, processing and payment acceptance across regions rather than doing just one slice, and has a reputation for backing non-obvious companies at the formative stage with founders like Robinhood's publicly noting that 75 investors shut doors in their face but Jan believed in them from the very start.

• A deep focus on B2B financial infrastructure and payments. He frequently highlights companies that solve complex backend financial problems or modernize business transactions, such as Apron for small business payments or Topi for hardware subscriptions.
• Valuing repeat founders and alumni from major tech success stories. He shows particular enthusiasm for backing entrepreneurs he has worked with before or who come from established unicorns, such as partnering again with a co-founder of Adyen on a new venture called Tebi.
• Interest in the intersection of artificial intelligence and financial security. He points out that as automation increases, so does financial crime, citing investments in companies like Resistant AI that use machine learning to fight fraud and protect financial systems.
• Backing tools that define the future of work and talent acquisition. He celebrates platforms that help companies manage distributed teams and hiring, noting that talent decisions are critical for growth as seen in his support for Beamery and Remote.
• Appreciation for products that democratize access and challenge incumbents through superior design. His extensive commentary on Robinhood highlights his admiration for founders who rewrite industry rules to let everyday people participate in systems previously reserved for the wealthy.
• Prioritizing global connectivity and the transatlantic bridge. He often mentions the movement of talent and capital between Europe and the US, celebrating European companies that successfully expand their operations to hubs like New York and San Francisco.