Computer Science
Backend & API Development Challenges
Backend & API Development challenges put you behind the systems that power every product, where you design the contracts other teams build on. You'll work through REST API Design and HTTP Fundamentals, build services with FastAPI, model data with GraphQL schema design, and harden access with OAuth 2.0 / JWT.
From there you'll handle the harder edges — API security (OWASP API Top 10), rate limiting, API versioning, multi-tenancy architecture, and API gateway patterns (Kong, Envoy) — the way platform teams actually run them in production. Each challenge you solve earns a verified credential you can share with recruiters.
- DesignIntermediateNew
Design a Versioning Strategy for a Public REST API
Receive the OpenAPI spec for the 14 endpoints, 8 months of partner-support tickets tagged 'breaking-change', and the partner-mix breakdown (which endpoints which partner uses). …
- REST API Design
- REST API Design
- API Versioning
API Design and GraphQL - DesignIntermediateNew
Design Schema Evolution for a Multi-Tenant Event Platform
Design a schema-evolution model covering: schema-registry topology (per-tenant subjects vs shared), compatibility modes per topic class (strict vs forward-only vs none), tenant-…
- Schema Evolution
- Kafka Event Streaming
- Schema Registry
Event-Driven Architecture - AnalysisIntermediateNew
Audit API Governance Across a Tier-1 Bank's Integration Estate
Inventory the API estate using a combination of Swagger/OpenAPI scrapes (where present) and stakeholder interviews. Build a scorecard covering: spec completeness, auth scheme, v…
- API Governance
- Openapi Spec
- Dora Compliance
Enterprise and Business Software Engineering - DesignIntermediateNew
Design a Geo-Distributed Storage Layer for an EdTech
Map the access patterns (90 percent reads from the country of origin, 10 percent cross-country via teacher reviewers). Design region routing using a metadata service backed by a…
- Geo Distribution
- Data Residency
- Cockroachdb
Distributed Systems Practice your coursework on real scenarios.
Every challenge is shaped from real industry context — not generic exercises. The work mirrors what your degree prepares you for.
Why Ewance
- CodeSeniorNew
Envoy WASM Filter for Per-Tenant Rate Limiting
Implement the filter in Rust using the proxy-wasm-rust-sdk. The filter computes a (tenant_id, endpoint, method) key, calls a Redis token-bucket service via a sidecar HTTP client…
- API Gateway Patterns (Kong, Envoy)
- Wasm
- Rust Programming
Service Mesh and Microservices Networking - DesignBeginnerNew
Design the Architecture for a Library Management System
Read the 30-page replacement RFP. Author a 15-page architecture document covering the C4 model levels 1-3 (context, container, component) for the new system: web app, mobile app…
- Software Architecture
- C4 Model
- Data Modeling
Software Engineering Foundations - DesignIntermediateNew
Counterfactual Explanations for an Insurance Pricing Model
You receive a trained LightGBM regression model (premium in GBP), the feature schema (28 features, 14 mutable from the customer's side), and 500 sample quotes. Use DiCE (Diverse…
- Counterfactual Explanations
- Dice Ml
- Interpretability
Explainable and Interpretable AI - CodeIntermediateNew
Ship a Streaming RAG Endpoint with Caching and Fallbacks
You will build a FastAPI service exposing one POST /chat endpoint that (1) streams tokens via Server-Sent Events, (2) caches identical (system_prompt, query, retrieved_context) …
- LLM API Integration
- Streaming
- Response Caching
LLM Application Development - Browse challenges
Explore role
Product Manager
Ship product that solves real user problems. Combine user research, prototyping, and stakeholder alignment to turn ambiguous briefs into measurable wins — the role at the centre of modern software teams.
- AnalysisBeginnerNew
Developer-Experience Audit of a Public API
Walk through the existing public API as a first-time developer using only the public docs, OpenAPI spec, SDKs (Python + JavaScript), and example repos. Run the first-hour test 3…
- Developer Experience
- REST API Design
- Audit Grade Documentation
API Design and GraphQL - AnalysisBeginnerNew
GDPR Article 25 Privacy-By-Design Review for a HealthTech API
Review the API specification (OpenAPI 3, provided, 42 endpoints). For each endpoint: identify data categories handled (special-category health data, identifiers, traffic data), …
- GDPR
- Privacy By Design
- REST API Design
Privacy-Enhancing Technologies - CodeBeginnerNew
REST API + Admin Dashboard for a Tutoring Marketplace
Map the 5 operator workflows by shadowing 2 operators for 4 hours (recordings provided). Design REST endpoints (Open API spec) covering each workflow with role-based scopes (ope…
- REST API Design
- Vuejs
- Rbac
Web Application Development - CodeBeginnerNew
Observability Injection: Distributed Tracing via Sidecars
Enable Envoy tracing with the OpenTelemetry tracer in Istio MeshConfig. Configure a Tempo backend with a Grafana frontend. Verify W3C tracecontext propagation across all 26 serv…
- Distributed Tracing
- Opentelemetry Instrumentation
- API Gateway Patterns (Kong, Envoy)
Service Mesh and Microservices Networking Build a verifiable portfolio.
Submissions become evidence. Reviewers with shipping experience score against a rubric; the result becomes a credential anyone can verify.
Why Ewance
- CodeBeginnerNew
Build a Protein Structure Search and Visualization Tool
Build a FastAPI backend wrapping Foldseek's easy-search command, returning top-20 hits with alignment metadata. Build a React frontend with a structure upload widget and a 3D vi…
- Biomolecular Structure
- Bioinformatics
- Full Stack Development
Computational Biology and Health Informatics - DesignBeginnerNew
Design a Production HTTP/2 Load Balancer Configuration
Design a multi-region topology: anycast edge -> regional Envoy clusters -> origin services. Specify HTTP/2 connection pooling (max connections per upstream, idle timeout), retry…
- Application Protocols
- Load Balancing
- API Gateway Patterns (Kong, Envoy)
Computer Networks - DesignIntermediateNew
Design an Idiomatic REST + Webhooks API for a Logistics SaaS
Read the team's draft + the public APIs of 3 reference logistics platforms (anonymized, briefing pack provided). Author a 5-page API design guideline covering URL structure (nou…
- REST API Design
- REST API Design
- Openapi
Software Design and Design Patterns - CodeBeginnerNew
Build a Booking Web App for a Boutique Hotel Group
Design the data model (properties, rooms, availability, bookings, guests). Build the Next.js app with the App Router: 4 public pages (search, results, room detail, checkout), 1 …
- Nextjs
- React
- REST API Design
Web Application Development - CodeIntermediateNew
Stand Up Contract Testing for a Microservices Backend
Inventory the 18 services and pick the 6 producer-consumer pairs with the most staging breakages in the last 90 days. Stand up a Pact broker (self-hosted or PactFlow trial). For…
- Contract Testing
- Pact
- Microservices Patterns
Software Testing and Quality Assurance - CodeIntermediateNew
Migrate an Internal Service from REST to gRPC
Receive the existing OpenAPI spec, the Go service code, and 7 days of traffic data. Pick the top 2 RPS-by-method endpoints and design Protocol Buffers (protobuf) message + servi…
- Grpc
- Protobuf
- REST API Design
API Design and GraphQL - DesignIntermediateNew
Migrate a Monolithic Database to a Sharded Topology
Analyze schema (32 tables) + query workload (anonymized 7-day pg_stat_statements export) to identify the right shard key per table. Most tables shard on user_id; identify the 4-…
- Database Sharding
- Postgresql Or Mysql
- Vitess
Distributed Systems - CodeIntermediateNew
Java EE Backend for Sustainable Fashion Marketplace
You are to build a RESTful API for EcoThreads using Java EE (Servlets, JPA, and MySQL). The API must support CRUD operations for products (with categories, sustainability rating…
- Java Ee
- REST API Design
- Jpa
Web and Mobile Application Development - DesignBeginnerNew
Integrate a Modern Order System with a Legacy SAP ERP
Map the 5 required integrations: order create (sync), pricing inquiry (sync, sub-300ms), inventory availability (sync, with cache), credit check (sync), order status events (asy…
- Enterprise Integration
- SAP Integration
- Apache Camel
Enterprise and Business Software Engineering - StrategyBeginnerNew
REST API Versioning Strategy for a 4-Year-Old Public API
Pick a versioning scheme (URI path vs header-based) and justify it against integrator behavior. Define the deprecation lifecycle: announce → deprecate → sunset, with concrete ti…
- REST API Design
- API Versioning
- Openapi
Engineering Software as a Service - DesignIntermediateNew
Drift-Detect + Self-Heal a Multi-Tenant Kubernetes Estate
Enable ArgoCD auto-sync with selfHeal + prune across all 28 clusters. Add Kyverno cluster policies enforcing baseline standards (registry, resource limits, network policy). Buil…
- Argocd
- Kyverno
- Drift Detection
GitOps and Continuous Delivery - CodeIntermediateNew
Design Prompt Versioning and Observability for a Coding Assistant
You will (1) design a prompt-registry data model (versions, owners, environments, change log) and implement it in Postgres + a small Python SDK, (2) instrument the assistant to …
- Prompt Versioning
- Observability
- Pii Scrubbing
LLM Application Development
How it works
From brief to credential, in six steps.
Step 01
Browse challenges aligned to your studies.
Step 02
Accept the one that fits your goals.
Step 03
Work through it with AI Copilot guidance.
Step 04
Submit for structured evaluation.
Step 05
Earn a verified credential.
Step 06
Add it to LinkedIn with one click.
Related skill families
Browse all skillsIndustry teams behind a decade of practitioner briefs
Hiring from this pool?
Sponsor a challenge and meet candidates through actual work.
Industry teams can shape briefs around the skills they hire for, then evaluate students on rubric-scored deliverables — not resumes.