Comparison

System Design interview prep vs SkillGaps

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

System Design interview prep

This app simulates system design interviews with an AI interrogator and interactive scenarios. Practice real-world architecture problems, receive instant feedback, and track your progress to ace your next tech interview.

Highlights
  • Interactive War Room for architecture scenarios
  • AI Interrogator challenges design decisions
  • Realistic system design interview questions
  • Daily practice drills for skill sharpening
  • Detailed performance analytics
  • Instant feedback and best practice learning
Features
Read full description

ArchSim is the ultimate training ground for software engineers preparing for system design interviews. Forget passive reading—ArchSim puts you in the driver’s seat of a high-stakes engineering simulation with a fast, value-first onboarding and a 60‑second drill preview to get you into the action quickly. Key Features: Interactive War Room: Solve real-world architecture scenarios in a dynamic environment. Define requirements, estimate capacity, and design your system component by component. AI Interrogator: Face off against an intelligent Prep AI that challenges your decisions, asks follow-up questions, and probes for weaknesses in your design. Realistic Scenarios: Tackle classic and modern interview questions like “Design a URL Shortener” and “Design a Social Network.” Perfect for your job search. Daily Drills: Short 5–10 minute practice sessions to build fundamentals, track streaks, and sharpen core skills. Detailed Analytics: Track your performance, identify knowledge gaps, and monitor your improvement over time with comprehensive metrics. Debrief & Learn: Get instant feedback on your design choices and learn best practices for scalability, reliability, and maintainability. Whether you are a junior developer or a staff engineer, ArchSim provides the practice you need to ace your next tech interview and land your dream job. ----------- Subscriptions automatically renew unless auto-renew is turned off at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours prior to the end of the current period. Terms of Use: https://calico-magnolia-61e.notion.site/archsim-terms-of-use-2c6 Privacy Policy: https://calico-magnolia-61e.notion.site/archsim-privacy-policy-2c

About

SkillGaps

Features
Read full description

SkillGaps helps software engineers find and close their skill gaps through AI-powered assessments, personalized roadmaps, and real interview preparation. KNOW WHERE YOU STAND Take a structured assessment tailored to your specialization. Get an objective grade (A, B, C, S) based on your answers, evaluated by AI. PERSONALIZED ROADMAP Get a step-by-step learning path built around your current grade and target role. Know exactly what to study next. LEADERBOARD See how you rank among engineers in your field, filter by country, company, and grade. Compete, improve, stay motivated. AI-POWERED PRO FEATURES - Full 30-question assessments with AI-graded open questions - Detailed per-question feedback and correct answers - Certificate of completion to share on LinkedIn - GitHub & LinkedIn profile analysis - Job Description matching - see how well you fit a specific role - Mock interview with AI interviewer and per-answer scoring - Salary benchmarks for your grade - Multiplayer Quiz - host team quiz rooms SkillGaps is built for engineers who want honest, structured feedback - not just another quiz app. Terms of use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

System Design interview prep4 screens
SkillGaps4 screens

Verdict

The call

The clearest difference is ads: SkillGaps at none against System Design interview prep's shown. SkillGaps also leads on update cadence (weekly vs monthly). System Design interview prep's advantage is iOS requirement (17.6 vs 26.2). On price, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. System Design interview prep sells 5 in-app purchases, starting at $3.99 per 7 days and SkillGaps sells 2 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

System Design interview prep ships an update monthly, SkillGaps weekly. The most recent releases landed on July 23, 2026 and September 12, 2026 respectively.

Scorecard3 real differences · 7 level
System Design interview prep versus SkillGaps: the parameters behind the verdict, then further details
ParameterSystem Design interview prepSkillGaps
PriceFreeFree
Rating1.0 (2 ratings) — better—
Positive reviews0.0% of reviews—
Number of ratings2 — better—
Update frequencyMonthlyWeekly — better
AdsYesNo — better
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhone, iPad — betteriPhone
Requires iOS17.6 — better26.2
Further details — not scored
Size89 MB13 MB
Age rating4+4+
DeveloperAbdelhak El MoussaouiVladislav Aliev

In-app purchases

5 purchases

System Design interview prep

Subscriptions5
  • Unlimited access$3.997 Days
  • Unlimited access$4.997 Days
  • Unlimited access$6.991 Month
Show 2 more
  • Unlimited access7 Days trial$12.991 Month
  • Unlimited access7 Days trial$99.991 Year
2 purchases

SkillGaps

Subscriptions2
  • SkillGaps Pro$9.991 Month
  • SkillGaps Pro$59.991 Year

Questions

Is System Design interview prep free?
System Design interview prep is free to download, with in-app purchases available.
Is SkillGaps free?
SkillGaps is free to download, with in-app purchases available.
Do System Design interview prep or SkillGaps have ads?
System Design interview prep shows ads; SkillGaps does not.
Which is updated more often, System Design interview prep or SkillGaps?
System Design interview prep ships an update monthly, and SkillGaps weekly. Most recently, System Design interview prep was updated on July 23, 2026 and SkillGaps on September 12, 2026.

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