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.
- 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
Web Application Development - StrategyIntermediateNew
Stand Up Contract Testing for a Logistics Microservices Backend
Using only the materials provided, choose and justify the six producer-consumer service pairs to migrate first. Read the 90-day staging breakage log to rank pairs by how much pa…
- Contract Testing
- Pact
- Microservices
Open coursework - DesignIntermediateNew
Build a Multi-Tenant Kubernetes Foundation for Veterinary-Clinic SaaS
Using the provided tenant tier specification and tenant roster, design and prototype a multi-tenant model where each tenant gets its own Kubernetes namespace for compute, its ow…
- Kubernetes
- Multi Tenancy
- AWS
Open coursework - CodeBeginnerNew
Build a Product Knowledge Graph for a Fast-Fashion Retailer
You receive 200 sample SKUs across 4 markets (Spain, Germany, Japan, Brazil) as CSVs with country-specific attribute names. Design an OWL ontology with shared classes for Produc…
- Knowledge Graphs
- Owl Ontology
- Rdf
Open coursework Practice your coursework on real scenarios.
Every challenge is shaped from real-world context — not generic exercises. The work mirrors what your degree prepares you for.
Why Ewance
- DesignIntermediateNew
Migrate a 6TB Social-Commerce Database to a Sharded Topology
Using the supplied schema specification and the seven-day anonymized query-workload export, decide the correct shard key for each table and justify it from observed access patte…
- Database Sharding
- Postgresql
- Vitess
Open coursework - StrategyIntermediateNew
Migrating from Relational to NoSQL for a Social Media Startup
You are given a simplified relational schema of SnapVibe's current database (users, posts, comments, likes). Your task is to: (1) analyze the limitations of the relational model…
- Nosql
- Mongodb
- Data Migration
Open coursework - CodeIntermediateNew
Build a Java EE REST API for the EcoThreads Marketplace
Using the EcoThreads operations file, the sample product catalog export, and the API requirements specification provided to you, design and implement a RESTful backend with Java…
- Java Ee
- REST API
- Jpa
Open coursework - 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
- Envoy
Open coursework - 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.
- 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
Open coursework - 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
Open coursework 
CodeIntermediateNewDrift-Detect and Self-Heal a Multi-Tenant Kubernetes Estate
Using the estate-case-file and the baseline-policy-spec, design a drift-detection and self-heal rollout for all 28 single-customer clusters built on ArgoCD continuous-sync (auto…
- Argocd
- Kyverno
- Drift Detection
Open coursework- 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
- API Design
Privacy-Enhancing Technologies 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 - 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…
- Envoy
- Wasm
- Rust Programming
Service Mesh and Microservices Networking - AnalysisIntermediateNew
Audit and Govern a Frankfurt Bank's Sprawling API Estate
Working only from the materials provided, examine the API estate and reach a defensible governance judgment. Read the situation record (estate-situation-file) to understand how …
- API Governance
- Openapi Spec
- Dora Compliance
Open coursework - 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
- Vuejs
- Rbac
Web Application Development - DesignIntermediateNew
Design Multi-Tenant Network Policies with Calico Tier Enforcement
Receive the cluster topology (120 customer namespaces + 4 platform namespaces), the application traffic patterns (frontend talks to backend talks to its tenant's database), and …
- Kubernetes
- Network Policy
- Calico
Container Orchestration with Kubernetes - DesignIntermediateNew
Redesign DataFlow's Architecture for Enterprise Sales
Working only from the materials provided (the engineering dossier, the current-system technical specification, the enterprise prospect requirements brief, and the reliability an…
- Microservices
- Multi Tenancy
- Cloud Architecture
Open coursework - 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 - AnalysisBeginnerNew
Developer-Experience Audit of a Public REST API
Using only the four provided materials, audit the version 3 candidate API as if you were a first-time developer. Read the audit charter ('audit_brief') to understand the foundat…
- Developer Experience
- API Design
- Documentation
Open coursework - 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
- Envoy
Computer Networks - 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 - CodeIntermediateNew
Prove a gRPC Migration for a Kubernetes Control-Plane API
Examine three things: the captured control-plane traffic record (`traffic-7d`), the current REST API specification (`openapi-spec`), and the representative Go service module (`g…
- Grpc
- Protobuf
- API Design
Open coursework - CodeBeginnerNew
Build a Crop-Disease Classifier for a Smallholder Agritech Startup
You receive a curated 22,000-image cassava-disease dataset across 5 classes (4 diseases + healthy) plus a labeled 1,200-image held-out test set. Train a CNN classifier (start wi…
- Image Classification
- Cnn Architectures
- Transfer Learning
Deep Learning for Computer Vision
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.
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