Here is Why Your Smartest Engineers Make the Dumbest Decisions
The Thinking Traps That Every Tech Leader Falls For (Including Me)
One sentence in a planning meeting was costing them 3 months and $250,000.
"We can't possibly ship that feature in 3 months," their senior architect declared. "The other big bank tried something similar, and it took them a year.
The room fell silent. Then came the nods of agreement. Meeting adjourned.”
A tech leader whom I was mentoring told me this story. As a mentor, I couldn't help but notice what their team had missed: they'd just fallen for a classic logical fallacy.
It wasn't until I was in a train back to home that I realized what had happened: they'd all fallen for a classic logical fallacy.
The Big Bank’s timeline had absolutely nothing to do with this team’s capabilities, team size, or scope. They’d let an appeal to authority shut down a critical conversation without even realizing it.
We all like to think we're rational. Logical. Data-driven.
Especially in tech, where decisions are supposedly rooted in evidence and precision.
But in the trenches of software delivery? Smart teams make questionable decisions all the time - not because they lack talent, but because they fall for thinking traps that have been tripping humans up for centuries.
These are logical fallacies: mental shortcuts and flawed arguments that sound convincing but lead us astray. I've fallen for most of these myself, sometimes in the same week!
Let's break down 10 of the most common ones that tech leaders and teams fall for, with examples you've probably heard - or said - yourself.
1. Ad Hominem
"You can't trust his take on Kubernetes. She's just a frontend dev."
You might have seen this happening in meetings. A junior developer raises concerns about container strategy, and instead of addressing her points, someone dismisses her based on her role.
Right?
This fallacy is simple: attack the person, not the argument. It's a fast way to shut down dissent- and a perfect way to miss valid feedback. In high-stakes meetings, the messenger often gets judged more than the message. It's toxic, especially when titles override insight.
2. Straw Man
"So, you're saying we should never use AI tools? That's ridiculous."
The CxO said when the security lead suggested caution with a new ML pipeline.
What he actually said was: "Let's be careful about how we implement this AI system."
But someone who wasn’t really paying attention, twisted his reasonable caution into an extreme position.
Twisting someone's nuanced take into an absurd extreme makes you look clever in the moment - but it erodes trust long-term. It's debate club behavior, not leadership.
3. Slippery Slope
"If we let the team skip one retro, soon they'll stop doing Scrum altogether and we'll be back to waterfall!"
One small step does not always lead to chaos. Teams evolve. Contexts change. Sometimes you need to pause an event to make space for real reflection. Fear-based thinking masquerading as discipline hurts agility.
I've seen entire agile transformations stall because leaders couldn't distinguish between principles and practices.
4. Appeal to Authority
"Google does it this way. So should we."
It’s a real story. An executive Director at one of my employers many years ago said that to the whole team. She was referring to the bean bags and pool tables. lol.
I thought, “That's great for Google. But you're not Google. You don't have their scale, their problems, or their resources.”
A friend shared a story about a startup she worked with that spent six months implementing a complex microservices architecture because "Netflix does it this way."
They forgot that Netflix adopted microservices after becoming massive, not before.
Blindly copying big names leads to mismatched tooling, bloated org design, and cargo cult Agile. Remember “Spotify Model”?
Learn from them, but don't outsource your judgment.
5. False Dichotomy
"Either we move fast, or we do it right."
This is the startup equivalent of a tantrum, and I've seen it thrown during deadline pressure.
Reality is more nuanced.
With intentionality, you can move fast and build sustainably.
False choices limit imagination. Leaders ask: "How might we do both?" The most innovative teams refuse to accept these either/or situations.
6. Red Herring
"Why are we debating testing coverage when our Cloud costs are exploding?"
Classic misdirection. Managers use this technique repeatedly to avoid addressing technical debt or key issues at hand.
Irrelevant distractions during discussions derail teams fast. It might be a panic move or a power play - but either way, it clouds judgment.
Good facilitators gently but firmly anchor conversations to the topic at hand. You’d notice this at the political debates and how some of the moderators bring the politicians back to the main question.
7. False Cause
"We adopted microservices and our team velocity dropped. Must be the microservices."
Maybe. But maybe not. Correlation is not causation.
Maybe your team lacked the tooling, skills, or culture needed for microservices. Maybe other factors changed simultaneously.
Complex systems demand root-cause analysis, not knee-jerk blame.
I once watched a team abandon a promising technology because of this exact reasoning, only to discover later that an unrelated organizational change was the real culprit.
8. Bandwagon Fallacy
"Everyone's launching AI copilots. We need one too."
When strategy follows hype, you're not leading - you're chasing.
Do you remember the blockchain rush of 2018. Companies pivoted entire roadmaps to include blockchain, not because it solved customer problems, but because everyone else was doing it.
Following the herd rarely leads to innovation. Or differentiation. Look inward: what does your customer actually need?
9. Circular Reasoning
"This process works because it's what we always use."
That's not proof - it's inertia.
Legacy systems and rituals often get a free pass because they've "always been there." Critical thinking means holding even your defaults up to the light. Some of the most transformative improvements come from questioning the unquestionable.
At my last company, we discovered our most sacred deployment process was actually creating the very bugs it was designed to prevent. (I challenged that, and the manager firmly told me that that’s how they did things.)
10. No True Scotsman
"No real Agile team would write detailed specs."
Gatekeeping what counts as 'real' anything is a recipe for division.
Agile is a mindset, not a membership club. Mature teams adapt their practices without sacrificing principles. They focus on outcomes, not orthodoxy.
Why This Matters
Logical fallacies aren't just academic trivia. They're silent killers of clarity. They show up in project plans, product roadmaps, architecture debates, sprint retros, and Teams or Slack flame wars.
They twist debates. Muddy strategy. Reinforce bad decisions. And worst of all? They make smart people feel stuck.
Great leaders don't just make better decisions - they create environments where clearer thinking becomes the norm.
A few years ago, I started a simple practice with my team. Whenever someone spots a logical fallacy in a meeting, they gently raised their hand and name it. No shame, no blame - just awareness. The difference was remarkable. Our discussions were sharper, our decisions clearer, and surprisingly, our meetings shorter.
So, the next time something feels off in a meeting, pause. Ask: "Are we reasoning clearly? Or just rehearsing bad habits?"
Because clarity isn't just a mindset - it's a skill.
Bonus: Two More Fallacies to Watch
11. Survivorship Bias
"These 3 startups succeeded after pivoting to B2B. We should too."
We love stories of winners. But we rarely hear from the 997 others who tried the same pivot and died.
You’ll notice this behaviour with startups, where founders constantly reference the same handful of success stories while ignoring thousands of failures following identical strategies.
Survivorship bias leads us to overestimate the odds of success and underestimate the risk.
Always ask: what are we not seeing?
12. Planning Fallacy
"We'll ship this in 6 weeks. The team is confident."
The team is always confident - until week 4.
Then come the "unexpected" complexities that were there all along.
The planning fallacy blinds us to complexity and unknowns. It's why projects run over budget, over time, and over everyone's patience.
Even pessimistic estimates are not pessimistic, they are often ‘optimistic’ pessimistic.
Buffer like a realist, not an optimist.
I now routinely ask my teams: "What would your estimate be if you were betting your own money on it?"
Final Thought
The more complex the domain, the more disciplined your thinking needs to be.
Logical fallacies are shortcuts - and shortcuts are tempting in fast-paced environments. But beware: they cost you clarity, credibility, and progress.
The best leaders aren't the ones with the fastest answers. They're the ones who can slow down the conversation just long enough to ask better questions.
What fallacies do you see most often in your teams? Which ones are hardest to shake off?
Let's name them, laugh at them—and outgrow them together.
P.S. If you enjoyed this post, share it with a colleague who's trying to build a more thoughtful tech culture. And drop a comment with the logical fallacy you're most trying to overcome. I'll go first: I'm a chronic victim of the planning fallacy when it comes to my DIY projects at home. Every. Single. Time.
I love seeing these fallacies transported into a different domain! I may do it myself by transporting them into the domain of doctor visits!
I think I often struggle with figuring out if I've got a false or true cause. I see people seeing up a false dichotomy in the wild often without getting called on it.
That'd be fantastic to read. Looking forward to seeing your post on fallacies.