Prove your GraphQL skills
Writing a query is easy. Designing a schema that clients love and servers can afford is not. Lemma records your GraphQL design and debugging through live sessions, adaptive assessments and real repositories.
What GraphQL competence looks like
A skilled GraphQL developer designs the schema around what clients need, not around database tables. They name types and fields consistently, use nullability deliberately, and evolve the schema with deprecations instead of breaking changes. Pagination follows a clear convention.
On the server, they batch data loading to avoid the N+1 problem, enforce authorisation at the field level, and limit query depth and cost so one request cannot take the service down. On the client, they normalise the cache, write fragments that match components, and handle partial errors without hiding them.
Schema design review with a practitioner
60 min · Learning · with Anya P.
Anya P. rated the session
Practitioner · after the call
Clear reasoning on schema design. Talked through trade-offs first.
Schema design
Types, interfaces, unions and nullability shaped around client needs and long-term evolution.
Resolvers and batching
Efficient resolvers, data loaders and spotting N+1 query patterns before they reach production.
Pagination and connections
Cursor-based pagination and consistent connection patterns across the schema.
Authorisation
Field-level access control and keeping sensitive data out of responses by default.
Query cost and security
Depth limits, complexity analysis and persisted queries to protect the server.
Client caching
Normalised caches, fragments colocated with components and cache updates after mutations.
What counts as evidence of GraphQL skills?
A line on a CV saying GraphQL is a claim. A reviewed session, an assessed level or a repository linked from your account is evidence. These are the kinds Lemma records against your GraphQL skill, each with where it came from. See the evidence methodology for how each source is weighed.
GraphQL
Chloe M. · SCI recomputed 9 Oct
Evidence · 4 entries
- Rated 5.0
Schema design review with a practitioner
Live session · 9 Oct
- Level 7.2
Adaptive GraphQL assessment
Adaptive assessment · 2 Oct
- Verified
A GraphQL server or client on GitHub
GitHub connector · 24 Sep
- Practice
Schema practice with the AI tutor
AI tutor practice · 11 Sep
Schema design review with a practitioner
Design or critique a schema for a real feature in a live session. The practitioner rates your naming, nullability and evolution choices.
Adaptive GraphQL assessment
Scenarios cover resolvers, pagination, caching and authorisation. Harder rounds show a slow or leaky resolver, and you pick the change that fixes it.
A GraphQL server or client on GitHub
Connect a repository or commit, such as adding data loaders to remove N+1 queries. Lemma checks it exists and that you have access.
Schema practice with the AI tutor
Practise modelling types and writing resolvers with adaptive exercises. Drills add a small, capped amount to practice and help you prepare for sessions.
How is a GraphQL skills test run on Lemma?
The GraphQL test runs 15 to 25 questions and adjusts difficulty to your answers, with scenarios from services under real load. The result counts alongside sessions and linked repositories toward your GraphQL SCI, which favours recent evidence over old.
A query for 50 posts with their authors sends 51 database queries. What fixes it?
- APaginate the posts field
- BBatch author lookups with a DataLoader
- CCache the whole response for an hour
- DMake author a non-null field
Design a schema live
In a session, you model a feature's schema with a practitioner and defend your choices. Expect questions about nullability, pagination, breaking changes and authorisation.
Diagnose resolvers in the assessment
The adaptive assessment scales with your answers. Harder scenarios show resolver code with a performance or security problem, and you choose the correct diagnosis. Each question is timed.
Connect your implementation
Link a GitHub repository with your GraphQL server or client. It sits beside your session ratings and assessment result under the GraphQL skill.
GraphQL skills: common questions
How do I prove GraphQL API design experience?
What is the N+1 problem in GraphQL and how do you fix it?
When should a team choose GraphQL over REST?
What GraphQL security risks should developers know about?
Skills related to GraphQL
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Evidence for ReactSystem design
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Evidence for system design
Start your GraphQL evidence record.
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