What are the most common pitch deck mistakes?

The most common pitch deck mistakes weaken the story or make the startup look superficial. The examples in this guide come from my deck reviews. Some of them are pitch roasts, where I review founders' decks openly on video. These mistakes come up again and again:

1. A competition table where only your startup ticks every box.
2. An executive summary right after the title slide.
3. A financial forecast that shows numbers but not the logic behind them.
4. A backup section full of slides you could not decide on.
5. Drama, detail and claims without clarity or proof.

What goes wrong on competition slides?

Many competition slides compare features that will not decide who wins the market. A typical example: a table with the startup in one column and competitors in the others. The startup ticks every box, and the competitors' columns are full of crosses.

I saw such a slide in the deck of an experienced founder team, which I reviewed as Managing Partner of Delin Ventures, an early-stage fund that invests in startups shaping the future of work. The first row of the table was the option to bookmark items, a simple feature that competitors could copy within a few days. This one slide showed three mistakes:

1. The cliché table: a comparison in which you tick all boxes and the others tick none.
2. Easy features: comparing features that others could easily build too.
3. The wrong first row: I expect the most important differentiator at the top. A weak one in the first row works against you.

The more important question is why your differentiators will decide who wins. I use a Formula 1 comparison: does Ferrari win a race because its cars are red, or because of the leather on the driver's seat? Other criteria decide the race. A strong competition slide names the few criteria that will separate future market leaders from the rest, and shows where you stand on each. Read more in Common mistakes in competition slides.

Why is an executive summary at the start a mistake?

An executive summary at the start asks investors to read a recap of a story you have not told yet. Many decks open with the logo on slide 1 and an executive summary on slide 2. It works like a film whose first scene is a narrator who tells you the whole plot: who the characters are, what happens and how it ends.

A stronger opening is a hook: a problem that feels urgent. From there, the deck can follow a clear order:

1. Start with the problem.
2. Show the opportunity.
3. Present your solution as the turning point of the story.

I learned to open decks with an executive summary as a strategy consultant, years ago, and had to unlearn it for fundraising. I often see such summaries in decks of founders who worked at McKinsey, BCG or Bain, three large strategy consulting firms. The full argument is in I hate executive summaries.

What should the financial forecast slide show?

The financial forecast slide should show that you understand the drivers of your business, more than any precise number. VCs (venture capital investors) know that early-stage startups face a lot of uncertainty and that most startups miss their projections.

Two extremes tend to backfire. Calling a forecast "conservative" rarely convinces, because investors know that early forecasts are seldom realistic. A forecast that is obviously unachievable does not help either. My rough guideline is a bullish forecast that is achievable with outstanding performance.

What VCs want to see in the forecast:

• Attractive projections: the numbers show a big business that can deliver venture returns.
• The mechanics: you know the variables that decide whether you earn $5 million or $50 million, and what drives your margins.
• Confidence in uncertainty: you understand the risks, have made smart assumptions and know how to reduce the risks. You can admit what you do not know, in a confident tone.

For very early-stage companies, leaving the financial slide out can be the better choice when the assumptions behind it are very unreliable. More in The endless dilemma of financial forecasts.

Should a pitch deck have backup slides?

Backup slides at the end of a deck often signal uncertainty more than preparation. I once had ten backup slides in a pitch myself. Several of them were slides I was unsure about, so I moved them to the backup section.

For the reader, a backup section is a random mix of unrelated pieces with no narrative and no ending. It is like a film that adds a bundle of random cut scenes after the credits. A useful test: if you already doubt whether a slide belongs in the main story, it probably does not. Then it does not belong anywhere in the deck. Three habits help:

• Build the deck like a story with a clear arc.
• Let each slide earn its place.
• Accept that some things stay out.

What makes a pitch deck look superficial?

A deck looks superficial when it creates drama or makes claims without clarity, depth or proof. Two of my pitch roasts show the typical forms.

Hyground, an AI copilot for DevOps teams (the teams that build and run software systems), created good tension with downtime scenarios, stressed IT managers and regulatory pressure. The deck still left open which incidents it meant, who exactly the target customer was and how often the problem occurs. After a promise of 85 percent faster incident resolution, the product appeared as a plain chat screenshot. That gave the impression of a simple layer on top of a large language model that anyone could build. The deck also used industry abbreviations without explanation and generic strategy phrases.

Datablaze, a startup working on AI agents for e-commerce, showed three other problems:

• Claims without depth: statements such as "stores not optimized for agents will die" without numbers, and an agency cost of "10k/month" without saying which agency or who pays.
• Inconsistency: switching between "brands", "stores" and "e-com shops", plus design noise and typos. Inconsistency hurts trust.
• Vague traction: "users are pouring in" next to 80 users and no real outcomes. When you show early proof, show outcomes and explain what you did for each named customer.

My conclusion from the Hyground roast: a pitch deck starts a conversation. It focuses on problem, solution, ideal customer profile (ICP, the type of customer you serve best) and traction, the evidence that customers want the product. The Hyground case is covered in full in Pitch roast: Hyground.