Finding the 80% Line in Engineering

Early in my career, I believed everything we built had to be perfect. Clean code, every edge case handled, no compromises. It felt like the “right” way to engineer. But I learned the hard way: in software, things will never - and I mean never - be 100% right. You can get to 80% in a few days. The remaining 20% - the polish, the edge cases, the extra patterns - can take weeks or months. That last mile rarely aligns with business goals, timelines, or the messy reality of how products are used. Chasing it is how you burn time, lose runway, and end up with “development hell.” The real skill is knowing where to draw the line: solid enough to ship, but not sunk in perfection. That’s what I call the 80% line.

Finding the line is a mix of gut, experience, and opposition. My 80% might not be the same as sales’ 80%. That tension is healthy - it forces clarity. For me, the signal often shows up in complexity. If we’re nailing down the basics and the feature is robust enough to stand, we’re in the sweet spot. If the complexity curve starts to spike - endless edge cases, cascading dependencies, theoretical scenarios - that’s where I stop.

Prototypes are the exception, but even there I tread carefully. Too many times I’ve seen a “throwaway demo” quietly morph into production code, dragging all its shortcuts into the future. Unless it’s crystal clear that the prototype will be rebuilt, it’s safer to aim for 80% robustness from the start.

The truth is, assumptions almost always diverge from reality. Users behave differently. Markets shift. Features evolve in directions we didn’t predict. That’s why chasing 100% from day one is sunk cost.

I’ve seen teams spiral into perfection mode. On the surface, it looks like craftsmanship. Underneath, it breeds tension. Business stakeholders don’t need 100% - they need something in customers’ hands to validate. If engineers keep perfecting, it leads to nervousness, then frustration. Eventually, it becomes development hell - polishing for the sake of polish. The result: features that never ship, products that stay in the oven too long, and companies that run out of runway. Startups, especially, don’t die because the code wasn’t perfect. They die because the product never left the building. Of course, you can also fall the other way. Ship too rough - 50% or 60% - and you risk user pain, reputation damage, or tech debt that piles up faster than you can clean it.

The way to avoid that is to build safety nets around your 80%:

• Validate the idea. Don’t just ship because someone thought it sounded good.
• Run QA. A simple smoke test beats blind hope.
• Dogfood it. Be your own user before asking customers to be.
• Roll out smart. Start with alpha or beta users, or canary releases. Don’t blast everyone at once.

With these in place, you can confidently stop at 80%. You’ll catch the rough edges before they hit the wider market.

Making the 80% Mindset Real

Explaining the 80% mindset to engineers is often harder than practicing it myself. Many still cling to the idea that code should be flawless. The only way to break that is with business context.

I keep it real: “This feature gets us to market in 6 months if we stop at 80%. It’ll take 15 months if we chase 100%. Those 9 months are pure expense - and we don’t even know yet if the feature will land.”

Engineers are clever. They get it when you frame it in terms of cost, risk, and uncertainty. The problem in many companies is that developers are kept far from the business, so they never see the trade-offs. I’ve found that once people share the responsibility, they naturally adapt. Nobody wants to sink the ship - especially if they share in the upside when it floats. Learning to find the 80% line changed how I lead. It pushed me to challenge my own technical lens - to resist over-engineering, and to teach my colleagues the same.

But it’s not just about code. Perfectionism creeps into product roadmaps, business plans, even operations. Nobody is immune. That’s why my default posture as a leader is to challenge, challenge, challenge. Doubt assumptions. Validate decisions. Ask outsiders for perspective when needed. Sometimes I even ask: what if we only did 40% now, and another 40% later? Breaking delivery into smaller cycles forces us to stay lean. Ship the minimum viable version, see how it lands, and then reinvest where it proves its worth. The 80% line isn’t a fixed threshold. It’s a mindset of balance: strong enough to stand, light enough to adapt.

For startups and small-scale companies this might even be on make it or break it level - investing too much into something that doesn’t need 100% may be an unwise spend of investment. I’d personally be more careful in this space, as money is more vulnerable and may be used on other important things. For bigger organizations, I’d aim for 80% too. They can afford to spend a bit more for sure, but do they need to? You can lose a lot of money on just a few bad gambles. Getting a landing done well is important in all settings.

Today, I consciously ask myself “is this enough?” That framing is sharper than asking if something is 80%. Enough to ship, enough to test, enough to learn. Everything above that is a bonus. Progress comes from consistency, not perfection. That mindset keeps me grounded and helps me keep the team grounded too.

Software will never be 100% right. The question is whether it’s right enough to move forward.

Perfection is comforting for engineers, but it’s deadly for companies. Shipping too rough is risky, but manageable with the right safeguards. The sweet spot - the 80% line - is where learning happens, where products reach customers, and where companies stay alive long enough to grow.

That’s the lesson I had to unlearn as an engineer, and relearn as a leader.