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ZAIN KHALIL KHAN
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Study Planner | Spaced Certification Scheduling

Certification study planner that allocates a finite study budget across exam domains by exam weight, knowledge gap, and retention decay since the last review, projecting readiness at the exam date rather than producing a flat topic checklist.

Live demo readySpaced Repetition + Certification Prep
Spaced RepetitionCertification PrepLearning ScienceSchedulingEducation TechnologySelf-AssessmentCase study / interactive demo

Case study

From problem to working system

Problem

Certification study planner that allocates a finite study budget across exam domains by exam weight, knowledge gap, and retention decay since the last review, projecting readiness at the exam date rather than producing a flat topic checklist.

My role

Full-stack software engineer

Solution

Certification study planner that allocates a finite study budget across exam domains by exam weight, knowledge gap, and retention decay since the last review, projecting readiness at the exam date rather than producing a flat topic checklist.

Architecture

The implementation combines the following technologies and system concerns.

Spaced RepetitionCertification PrepLearning ScienceSchedulingEducation TechnologySelf-Assessment

How it was built

  • Allocated hours by exam weight times knowledge gap, so time flows to the domains where study converts into score.
  • Applied an Ebbinghaus-style retention decay, which makes a well-known but long-untouched domain reclaim time ahead of a weak domain reviewed yesterday.
  • Projected readiness at the exam date with diminishing returns per hour, rather than assuming study time converts linearly into knowledge.
  • Converted the allocation into concrete session counts, because 4.2 hours is a number and three sessions is a plan.

Security decisions

No project-specific security control is documented in the current project record. The case study avoids claiming controls that were not verified.

Major challenges

  • Allocated hours by exam weight times knowledge gap, so time flows to the domains where study converts into score.
  • Applied an Ebbinghaus-style retention decay, which makes a well-known but long-untouched domain reclaim time ahead of a weak domain reviewed yesterday.
  • Projected readiness at the exam date with diminishing returns per hour, rather than assuming study time converts linearly into knowledge.

Verified evidence

Results and measurable impact

  • Projected readiness at the exam date with diminishing returns per hour, rather than assuming study time converts linearly into knowledge.
  • Converted the allocation into concrete session counts, because 4.2 hours is a number and three sessions is a plan.
  • Recommended recall-first sessions for decayed domains and practice questions for genuine gaps, since the two need different study modes.
  • Kept the budget finite and visible, so adding a domain visibly takes hours from another instead of expanding the plan indefinitely.

No separate numeric outcome is documented, so this section shows shipped technical evidence without inventing metrics.

Screenshots and access

Product view

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Interactive Demo

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Study Planner

Product workspace

Study PlannerWorkspace3 updates
Study Planner · Spaced Allocationprojected readiness at the exam date on 40h of study
45% → 79%

Study time should go where exam weight meets a knowledge gap, discounted for how long ago you last touched the material. That last term is what makes this spaced repetition: a domain you know well but have not reviewed in three weeks reclaims hours ahead of a weak domain you covered yesterday.

Study budget

40h

28 days at 10h/week

Current readiness

45%

weight-adjusted

Projected

79%

if the plan is followed

Decayed domains

1

retention below 40%

Projected28 days out
79%at exam
Hours allocated per domain40h budget
Readiness today45%
Readiness at exam date79%

Marked bars are domains whose retention has decayed below 40%. Those get a recall session before practice questions.

Allocation
Implementation25% of exam confidence 50% · retention 66% last reviewed 6d ago11.0h7 sessions
28% of budget

Largest genuine knowledge gap at meaningful exam weight. This is where hours convert into score.

Architecture & design21% of exam confidence 45% · retention 47% last reviewed 11d ago10.7h7 sessions
27% of budget

Largest genuine knowledge gap at meaningful exam weight. This is where hours convert into score.

Governance, risk & compliance14% of exam confidence 30% · retention 27% last reviewed 19d ago8.5h6 sessions
21% of budget

Retention has decayed materially. Schedule a recall session first, then practice questions, not the other way round.

Threats & vulnerabilities24% of exam confidence 70% · retention 81% last reviewed 3d ago6.7h4 sessions
17% of budget

Maintain with short spaced reviews so it does not decay before the exam date.

Operations & incident response16% of exam confidence 80% · retention 87% last reviewed 2d ago3.1h2 sessions
8% of budget

Maintain with short spaced reviews so it does not decay before the exam date.

Zain Khalil Khan