Demonstrating Impact

Failing to demonstrate enough impact is one of the most common reasons why engineers get downleveled or rejected. Before your next behavioral interview, make sure you’re equipped with a minimum of five clear impact statements. It’s the baseline requirement. Without metrics, interviewers can’t evaluate the scope, complexity, or scale of your past projects.

In this lesson, you’ll learn how to discover meaningful metrics from past projects, even when the numbers are fuzzy or you no longer have access to your past data.

Impact is more than just metrics

Though impact and metrics are buzzwords, most candidates still miss the mark—assuming they nailed it when they haven’t.

Impact is how you show your work mattered. It’s a clear statement of how your work drove meaningful results and created business value. It’s most commonly expressed in revenue gained, cost savings, or other measurable outcomes to show impact.

Grunt work is the opposite of impact. It’s a list of work tasks with no real context or purpose. If you only talk about what you did or how you did it—and skip why it mattered—you’re describing grunt work, not impact.

Why do you need impact?

One of the most common mistakes in behavioral interviews is failing to show impact.

Interviewers across all tech companies thirst to hear more impact. Without it, they can’t get a sense of the complexity, scope, or scale of your work.

An analogy will help here.

Imagine you’re interviewing the architect of the Empire State Building. The architect tells you, “I led a very big team, managed a sizable budget, and we made a really big building.” That’s not very clear.

Compare to this version of real signal:

“I led a crew of 3,000, managed a $40 million budget, and delivered a 1,250-foot structure, which at the time it was built, made it the tallest building in the world.”

From an interviewer’s perspective, if you just list tasks, you’re describing grunt work. When you add impact, you show your true value.

Why prepare five impact statements?

Most behavioral interviews won’t focus on more than five projects. One solid impact statement per project gives you enough coverage to deliver a strong impression.

Why is impact often overlooked?

The biggest mistake? Setting the bar too high. Engineers often assume something like: “If I’m going to give numbers, the figures need to be exact.”

That level of precision, which may help you write clean code, can hold you back in behavioral rounds. Lower the bar. For all the numbers related to your past projects, your best guess is good enough. No one expects exact numbers, especially if the project is from a past job.

How do I find metrics and impact?

If you’ve worked on large-scale systems, you’re in luck. The impact often speaks for itself.

For each past project, ask yourself:

• What was the deployment footprint? How many devices or users did it launch to?
• What was the scale of the data you worked with? What was the row count, cardinality, and update frequency?
• How much revenue or activation uplift did it generate?
• How much did it cut costs?
• Roughly how much data volume or financial value flows through the system you built?

How to estimate revenue impact (or cost savings) from a past project

Let’s say your math doesn’t add up to $1.4M—it’s much smaller.

For example, suppose you built an automation that reduced a task from one hour to under one second. It’s used by five salespeople, each earning $35/hour, once a week:

$9K saved per year = (1 hour) x (5 salespeople) x ($35/hour) x (1/week) x (52 weeks)

Should you mention, “This project cut costs by $9K.” to a Tier-1 company? No. That figure is too small to signal impact at high-scale companies. It will unintentionally make your work sound insignificant. When that happens, it can be a dealbreaker.

Instead, say, “My automation increased the speed of sales processes by 60 times.”

Or even a “2x” or “3x” improvement sounds more impressive than quoting a small dollar amount.

How to show impact without revenue or cost

Ask yourself these questions for anything you built or helped build:

• How much more accurate, effective, or efficient was it compared to a baseline or benchmark?

  For example: “This new in-app search ranking algorithm boosted user adoption by 30% over target, helping users surface underused product features more effectively.”

• How much did it boost efficiency or productivity? (Look for ways your work made things faster, easier, or more scalable.)

  For example: “My infrastructure automations cut new hire ramp-up time by 50%.”

• What did users or colleagues say about it? (Even anecdotal feedback can show meaningful impact, especially when metrics aren’t available. It might not be as optimal, but it’s better than no impact at all!)

  For example: “This became a milestone in our user onboarding process and dramatically boosted engagement.”

Use scope to highlight your impact

Use numbers to highlight the scale of your leadership or cross-functional impact:

• Convey team leadership: Mention the size of the team.

  For example:

  “I led a team of five senior ML engineers” is stronger than “I acted as team lead for this project.”

• Cross-org (or cross-company) impact: Mention the size of the org (or company).

  For example:

  “The daily automated rollbacks for unused feature flags I built were rolled out across the entire org of 200 engineers” is stronger than “I rolled out automated feature flag rollbacks across the org.”

Key Takeaways

Now you know how to find impact. No more excuses.

Find at least five (more if you can), and use them liberally in your next interview. Later in the course, we’ll walk you through how to use these five impact statements into an ideal structure for behavioral answers.