When a startup is successful beyond anyone’s imagination, a question naturally arises: Why did it take off? Ask 10 people involved with the company and you’ll get 10 different stories: for one, it was the founder; for another, early access to its target audience; for a third, it was pricing that set it apart from its competitors; and so on. Then there are companies that tackle a smart area in an emerging market, have a great team, work diligently and still fail miserably. Many postmortems have been written on the reasons why a startup failed (here’s a list of 101 of them). While there are a million unique problems for every individual technology company, in order for a company to be successful at all, it needs three things—or more specifically, three types of people: Finders, Minders and Grinders.

Finders: Sales and Marketing Teams

The sales and marketing team members are your Finders. From positioning your product to finding your audience, it is their job to get you in front of the right people—and a lot of them. This role changes over time, and involves fulfilling very different needs in the early stages (e.g., getting you to your first five customers) versus the later stages (e.g., getting you to your next million). Technical founders sometimes tend to underplay this role, or are very reticent to be “salesy”—but at their best, Finders are not just salespeople or marketers, but “people people” who know how to find them and what to say when they do.

Minders: Management

You can’t do everything alone; a crucial element for success is being able to inspire people to do it with you. A poor conception of management is the stereotype of a micro-manager ruling over others with a task list. A better conception of management is a captain steering a vessel straight on course, adapting where necessary, giving other clear roles and expectations and enabling them to succeed at these goals. In the early stages, the Founder usually plays this role, and well. As the company grows, this role multiplies and divides and becomes one of the most crucial parts of the company’s future success.

Grinders: Engineering

In most scenarios, your idea doesn’t matter without your ability to execute. That’s where Grinders come in. Without your Grinders, the company stays in ideation mode. A telltale sign of a company lacking Grinders are great meetings that fail to produce any results. While this specifically applies to the engineering team, it also applies more generally to the growth hacker culture of getting stuff done. Thanks to YCombinator and many others, this role has increasingly received the appreciation it deserves.

A Word to Founders

At the end of the day, these three roles require each other, and that need is never rooted more clearly than in the Founder. As the lifeblood of the organization, the Founder needs to embody all three roles. Founders must cast the vision so others catch it; they must be able to guide others on the path to success, and they need to be the primary Grinder—getting things done by whatever means necessary and with tremendous effort so others follow by example. As a company grows, many of the more painful junctures are the ones where a Founder needs to let go of these roles and invite others to take these responsibilities so that the organization can grow. A necessary but not easy task—since they are the lifeblood of the organization from inception.

Rich Levandov is Partner at Avalon Ventures.