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). …
- API Design
- REST
- API Versioning
API Design and GraphQL - DesignBeginnerNew
Design a Resilient Bridge Between New Commerce and Legacy SAP
Using the integration requirements case file, design how all five interactions move between the storefront and SAP ECC: order create, pricing inquiry, inventory availability, cr…
- Enterprise Integration
- SAP Integration
- Apache Camel
Open coursework - 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 - 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 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
- 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 - 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 - 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 - 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…
- API Design
- REST
- Openapi
Software Design and Design Patterns - 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.
- CodeIntermediateNew
Add Idempotency Keys to a Payment Webhook System
Read the current Go webhook-sender code and 30 days of duplicate-delivery incident logs. Design the idempotency scheme: server-generated key per event (UUID v7 — time-ordered), …
- API Design
- Idempotency
- Webhooks
Open coursework - 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 - 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 - 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 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
- 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
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
- Schema Registry
Event-Driven Architecture 
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- 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 - 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 - 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 - 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 - CodeIntermediateNew
Build a GraphQL Federation Schema for an E-Commerce Platform
Receive the existing 22 REST endpoints' OpenAPI specs and a list of 5 priority subgraphs. Design a federated GraphQL schema using Apollo Federation v2 directives (@key, @externa…
- Graphql
- Graphql Federation
- API Design
API Design and GraphQL - DesignIntermediateNew
Design a Region-Routed Storage Layer for a Nordic EdTech
Working only from the materials in this file, produce a recommendation for how Lärnova should store student assignments so each country's data stays in its home region. Start by…
- Geo Distribution
- Data Residency
- Cockroachdb
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 - 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 - 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
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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