GMAT · GRE · SAT test prep

Prep with someone who's scored in the 99th percentile.

David de Koos scored in the 99th percentile on both the GMAT and the GRE, has spent over a decade tutoring for some of the world's top test-prep companies, and teaches college students for a living. He's helped students push their GMAT as high as 770.

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99th
Percentile scorer, GMAT & GRE
10+ yrs
Tutoring with top test-prep firms
770
Highest GMAT score coached to date
1:1
Also a working college instructor
Why bother

Fewer people are taking these tests. That's exactly why a strong score works harder.

Test-optional policies have pulled the number of GMAT, GRE, and SAT takers down over the last several years. That doesn't make the tests pointless, it changes what a good score does for you.

When submitting a score is optional, the applicants who do submit it are self-selecting for confidence. A strong result is one of the only things in an application that's directly comparable across every other candidate, regardless of school, major, or who wrote their letters.

  • Merit scholarships and fellowships are frequently still tied to score bands, even where general admission has gone test-optional.
  • A score gives an admissions committee a fast, low-risk signal for candidates whose transcript or background they know less well, career-switchers, international applicants, nontraditional paths.
  • The reasoning these tests measure, fast, precise, structured thinking under time pressure, carries directly into the coursework, case interviews, and exams that follow.
Score distribution image goes here Replace this block with an image showing the 99th percentile on a score distribution.
Test details

GMAT, GRE, and SAT are not the same test.

Each one rewards a different skill set and serves a different application. Pick your test above, or use the tabs below, the coaching approach is tailored to whichever one you're actually taking.

GMAT Focus Edition

What the GMAT actually tests

  • Adaptive across three sections: Quantitative Reasoning, Verbal Reasoning, and Data Insights
  • Rewards fast, precise reasoning under a hard time cap
  • The primary benchmark most MBA and business master's programs weigh applicants against
  • Often tied directly to merit scholarship decisions

Who it's for

Applicants to MBA programs, MS in Finance, MS in Business Analytics, and other business master's degrees.

Why prep the GMAT with David

  • Scored in the 99th percentile himself
  • Over a decade coaching the GMAT specifically, with top test-prep firms
  • Has guided students to scores as high as 770
Start GMAT prep →
David de Koos
About your tutor

David de Koos

[Add David's bio here], a couple of paragraphs on his path into tutoring, what he teaches at the college level, and how he approaches a first session. Lead with the credibility markers below; they're already doing a lot of the persuading.

  • %99th percentile scorer on both the GMAT and the GRE, in his own right.
  • 10+Over a decade tutoring GMAT and GRE with some of the world's top test-prep companies.
  • 🎓Currently a college instructor, teaching in the classroom in addition to one-on-one coaching.
  • 770Has guided students to GMAT scores as high as 770.
David's intro video goes here Replace this block with your YouTube/Vimeo embed <iframe>, a 60–90s clip of David talking about test-taking works best.
Free resources

Test-day tips, on video.

Short lessons from David's YouTube channel, pacing, common traps, and section-by-section strategy. Add each video here as it's published.

GMAT
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GRE
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SAT
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GMAT
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GRE
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SAT
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Results

What students say

Drop in real quotes and score jumps as they come in, the more specific the number, the harder it works.

★★★★★
[Add a testimonial here, ideally naming the score improvement, e.g. "went from a 620 to a 710 in six weeks."]
[Student name or initials] · [Test], [Score improvement]
★★★★★
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[Student name or initials] · [Test], [Score improvement]
★★★★★
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[Student name or initials] · [Test], [Score improvement]
Rates

Different Pricing Options, Depending on your Needs and Timeline

One-on-one, tailored to your test and target score, or join a small cohort and prep alongside other students.

Single session
$200 USD / hour

Pay as you go. Good for a diagnostic session, a targeted topic, or ongoing prep at your own pace.

Book an hour
Cohort coaching
Inquire for details
12 weeks · a more economical option · cohorts begin once at least 4 students have enrolled

A structured 12-week group program for students who want peer accountability alongside David's coaching. Small enough that everyone still gets direct attention.

Inquire for more information

Sessions are held online. [Confirm timezone, session length default, cancellation policy, and next cohort start date here]

Get in touch

Ready to start?

Tell David which test you're taking, your timeline, and your target score, or just pick "Free 30-Minute Trial Session" below if you'd rather talk it through first. He'll follow up to schedule a time.

Book a free 30-minute trial session →
Email
[Add David's email]

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Before this goes live: a checklist for Erin

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  • Add the score-distribution image once you've found one, in the "Why bother" section.
  • Populate the video-tips grid once the YouTube channel exists.
  • Add real testimonials as they come in, even one or two with a specific score jump will outperform generic praise.
  • Confirm session length, timezone, cancellation policy, and next cohort start date for the pricing section.
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