Dev Skill Programme
Members

Developer D

Mobile Engineer (iOS) · dev.d@example.com · primary skill: Mobile · owns Mobile

Skills

SkillVerifiedSelfTargetChecklistPrimary
BackendDDC
0/29
WebCBC
0/13
MobilePrimaryAAA
0/24

Assessment history

  1. Verified gradeBackendDFundamentalQ&A 62.5%Low confidence25 Aug 2026

    Confirmed at this level against the evidence on file.

    Q&A — 20 questions
    • CorrectWhat is the difference between a primary key and a foreign key? · Database · Basic 1pt
    • CorrectExplain one-to-many and many-to-many relationships, and how each is stored. · Database · Basic 1pt
    • CorrectWhat does NULL mean in SQL, and why does `WHERE col = NULL` not work? · Database · Basic 1pt
    • CorrectWhat are the common HTTP methods and what is each used for in a REST API? · API · Basic 1pt
    • CorrectWhat do the status code families mean? Give an example of each: 2xx, 4xx, 5xx. · API · Basic 1pt
    • CorrectWhat is the difference between authentication and authorization? · API · Basic 1pt
    • CorrectWhat is the difference between INNER JOIN and LEFT JOIN? When would you use a LEFT JOIN? · Database · Intermediate 2pt
    • CorrectWhat is the difference between WHERE and HAVING? · Database · Intermediate 2pt
    • CorrectWhat is an index, what does it cost, and when should you add one? · Database · Intermediate 2pt
    • CorrectWhat is a transaction, and what does ACID stand for? · Database · Intermediate 2pt
    • CorrectWhat does idempotent mean? Which HTTP methods are idempotent? · API · Intermediate 2pt
    • CorrectWhere should input validation happen, and what should the API return for invalid input? · API · Intermediate 2pt
    • CorrectHow does token-based authentication with a JWT work, and where are its weaknesses? · API · Intermediate 2pt
    • CorrectCompare offset pagination with cursor pagination. · API · Intermediate 2pt
    • CorrectExplain transaction isolation levels and one anomaly that READ COMMITTED allows. · Database · Advanced 3pt
    • WrongA report query became slow in production. How do you investigate and fix it? · Database · Advanced 3pt
    • WrongHow do you run a schema migration on a large live table without downtime? · Database · Advanced 3pt
    • WrongHow would you ship a breaking change to an API that mobile apps already use? · API · Advanced 3pt
    • WrongHow do you protect an API against abuse or traffic spikes? · API · Advanced 3pt
    • WrongA request is slow only sometimes in production. How do you find the cause? · API · Advanced 3pt

    Dimensions

    • KnowledgeC
    • ImplementationD
    • Code UnderstandingD
    • DebuggingE
    • DesignE
    • CommunicationD

    Independence from AI

    Can explain AI-generated codePartly
    Can modify AI-generated codePartly
    Can identify incorrect AI-generated codeNo
    Can debug without AINo
    Can make technical decisions without blindly following AINo

    Largely dependent on AI output (20%).

    Evidence cited (1)

    • Knowledge questions

    Assessor: Developer B· Skill owner review· next assessment 29 Oct 2026

  2. Verified gradeWebCWorkingQ&A 71.9%Medium confidence25 Aug 2026

    Good grasp of the concepts, and explains the happy path well. Could not yet talk through the failure modes without help.

    Q&A — 16 questions
    • CorrectWhy does semantic HTML matter? Give examples of semantic elements. · Web fundamentals · Basic 1pt
    • CorrectExplain the CSS box model. · Web fundamentals · Basic 1pt
    • CorrectWhen would you use flexbox and when grid? · Web fundamentals · Basic 1pt
    • CorrectWhat is the difference between `let`, `const` and `var`? · Web fundamentals · Basic 1pt
    • CorrectWhat are props and state in a component, and how do they differ? · Application development · Basic 1pt
    • CorrectExplain the event loop, and in what order `setTimeout(…, 0)` and a resolved Promise callback run. · Web fundamentals · Intermediate 2pt
    • CorrectHow does `async`/`await` relate to Promises, and how do you handle errors with it? · Web fundamentals · Intermediate 2pt
    • CorrectWhen should state be lifted up, and when do you need shared or global state? · Application development · Intermediate 2pt
    • CorrectWhen calling an API from a screen, which states must the UI handle? · Application development · Intermediate 2pt
    • CorrectWhy do list items need a stable `key`, and why is the array index a bad key? · Application development · Intermediate 2pt
    • CorrectHow do you make a form accessible? · Quality · Intermediate 2pt
    • CorrectCompare client-side rendering, server-side rendering and static generation. How do you choose? · Application development · Advanced 3pt
    • CorrectWhat are Core Web Vitals, and how would you improve a poor LCP? · Quality · Advanced 3pt
    • WrongExplain XSS and how to prevent it. · Quality · Advanced 3pt
    • WrongWhat is CORS and why does the browser enforce it? · Quality · Advanced 3pt
    • WrongA page feels slow when typing in a search box. How do you find and fix the cause? · Quality · Advanced 3pt

    Dimensions

    • KnowledgeB
    • ImplementationC
    • Code UnderstandingC
    • DebuggingD
    • DesignD
    • CommunicationC

    Independence from AI

    Can explain AI-generated codeYes
    Can modify AI-generated codeYes
    Can identify incorrect AI-generated codePartly
    Can debug without AIPartly
    Can make technical decisions without blindly following AIPartly

    Mostly in control, some reliance (70%).

    Evidence cited (2)

    • Practical task
    • Knowledge questions
    Weak areas
    State management and accessibility.
    Recommended learning
    Rebuild one screen with hoisted state, then run a keyboard-only pass.

    Assessor: Developer C· Skill owner review· next assessment 28 Dec 2026

  3. Verified gradeMobileAAdvancedQ&A 91.4%High confidence25 Aug 2026

    Confirmed at this level against the evidence on file.

    Q&A — 18 questions
    • CorrectWhat are the main states of a mobile app lifecycle, and why do they matter? · Mobile fundamentals · Basic 1pt
    • CorrectWhy must long-running work never run on the main (UI) thread? · Mobile fundamentals · Basic 1pt
    • CorrectWhat is an optional in Swift, and what are safe ways to unwrap it? · iOS · Basic 1pt
    • CorrectWhat is the difference between a struct and a class in Swift? · iOS · Basic 1pt
    • CorrectHow does Kotlin handle null safety? · Android · Basic 1pt
    • CorrectWhat happens to an Activity on a configuration change such as rotation, and how do you keep data? · Android · Basic 1pt
    • CorrectHow do you handle an unreliable network in a mobile app? · Mobile fundamentals · Intermediate 2pt
    • CorrectExplain `@State`, `@Binding` and `@Observable` / `@StateObject` in SwiftUI. · iOS · Intermediate 2pt
    • CorrectHow do you make a network request with async/await and update the UI safely? · iOS · Intermediate 2pt
    • CorrectWhat is a retain cycle and how do you avoid one with closures? · iOS · Intermediate 2pt
    • CorrectWhat is recomposition in Jetpack Compose, and why hoist state? · Android · Intermediate 2pt
    • CorrectDescribe MVVM on Android: what belongs in the ViewModel and what in the repository? · Android · Intermediate 2pt
    • CorrectWhat is structured concurrency with coroutines, and why use `viewModelScope`? · Android · Intermediate 2pt
    • CorrectHow do you release a mobile app safely, given users update slowly? · Mobile fundamentals · Advanced 3pt
    • CorrectWhat problems do actors and `@MainActor` solve in Swift concurrency? · iOS · Advanced 3pt
    • CorrectExplain certificates, provisioning profiles and how an app gets onto TestFlight. · iOS · Advanced 3pt
    • CorrectExplain cold vs hot flows, and the difference between `StateFlow` and `SharedFlow`. · Android · Advanced 3pt
    • WrongHow do you sign and release an app on Google Play, and how does a staged rollout help? · Android · Advanced 3pt

    Dimensions

    • KnowledgeA
    • ImplementationA
    • Code UnderstandingA
    • DebuggingA
    • DesignA
    • CommunicationA

    Independence from AI

    Can explain AI-generated codeYes
    Can modify AI-generated codeYes
    Can identify incorrect AI-generated codeYes
    Can debug without AIYes
    Can make technical decisions without blindly following AIYes

    Understands and controls the solution (100%).

    Evidence cited (5)

    • Architecture explanation
    • Code review
    • Real project contribution
    • Debugging task
    • Knowledge questions

    Assessor: Developer A· Skill owner review

  4. Self assessmentBackendDFundamental20 Aug 2026

    Completed the concept session and the first block of the checklist.

    Dimensions

    • KnowledgeC
    • ImplementationD
    • Code UnderstandingD
    • DebuggingE
    • DesignE
    • CommunicationD

    Recorded by the member· Self assessment

  5. Self assessmentWebBProficient20 Aug 2026

    Completed the concept session and the first block of the checklist.

    Dimensions

    • KnowledgeA
    • ImplementationB
    • Code UnderstandingB
    • DebuggingC
    • DesignC
    • CommunicationB

    Recorded by the member· Self assessment

  6. Self assessmentMobileAAdvanced20 Aug 2026

    Primary skill — day-to-day work in this area.

    Dimensions

    • KnowledgeA
    • ImplementationA
    • Code UnderstandingA
    • DebuggingA
    • DesignA
    • CommunicationA

    Recorded by the member· Self assessment

Active assignments

  • Backend → C

    due 13 Oct 2026

    Focus on tables, keys and relationships first.

Sessions presented

Has not presented a session yet.

Attended 2 sessions.