Computer Science
Database & Storage Challenges
Database & Storage challenges put you inside the work of designing data layers that stay fast and correct under load. You'll develop skills in Data Modeling, Database Schema design, and Domain Modeling, and you'll write SQL with JOINs & Aggregations against PostgreSQL or MySQL.
From there you'll handle the harder edges — Indexing strategy, Query optimization, Replication basics, and Multi-region writes — working through High availability & disaster recovery and Oracle database administration the way data teams actually do. Each challenge you solve earns a verified credential you can share with recruiters.
Recommended Challenges
- CodeIntermediateNew
Design a Change-Data-Capture Pipeline for an E-Commerce Reseller
Receive the MySQL schema (220 tables), 7 days of binlog samples, and the data team's freshness + correctness requirements. Design the CDC pipeline: Debezium for MySQL binlog cap…
- Change Data Capture
- Debezium
- Kafka
Big Data and Data-Intensive Systems - DesignIntermediateNew
Design a Zero-Downtime Multi-Region PostgreSQL Migration for an EdTech Platform
Using the infrastructure inventory (infra-inventory), the database schema sample (schema-subset), the workload metrics (workload-metrics), and the service-level brief (sla-brief…
- Blue Green Deployment
- Logical Replication
- Postgresql
Open coursework - DesignIntermediateNew
Resolve the Quota Double-Spend: Design Meterly's Order-Provisioning Schema
Working only from the materials provided, reach and defend a database design. Read the de-identified incident record (incident-file) and the business-rules brief (requirements-b…
- Transactions
- Acid
- Isolation Levels
Open coursework - CodeIntermediateNew
Plan Warehouse Pick Routes with a Classical Planner
You receive a stylized warehouse map (aisle graph), 30 sample shifts of pick tasks, and the current heuristic's outputs. Write a PDDL domain + problem generator, solve with at l…
- Pddl Modeling
- State Space Search
- Classical Planning
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
- AnalysisBeginnerNew
Author a Ubiquitous-Language Glossary for a Telco Billing Domain
Conduct 12 structured interviews (30 min each) with stakeholders across CRM, billing, AR, customer portal, and finance. Capture each team's terminology for the top 25 domain con…
- Ubiquitous Language
- Context Mapping
- Stakeholder Interviews
Domain-Driven Design - DesignBeginnerNew
Optimizing Inventory for a São Paulo D2C Cosmetics Brand
You are given a CSV file with raw sales, inventory, and supplier data. Your task is to design an E/R diagram, create the normalized relational schema in 3NF, populate it with sa…
- SQL
- Database Design
- Normalization
Open coursework - DesignBeginnerNew
Optimizing Inventory for a Toronto D2C Cosmetics Brand
Your task is to design a multidimensional data model (star schema) for inventory management, create an ETL pipeline to load sample data (provided as CSV files), and develop an O…
- Data Warehousing
- Etl
- Olap
Open coursework - CodeIntermediateNew
Design an Anti-Corruption Layer for a Legacy Hospital EHR
Map the legacy EHR's HL7 v2 message schema (ADT, ORM, ORU segments) to the new platform's domain (Patient, Encounter, Order, Result). Identify the 6-10 anti-patterns in the lega…
- Anti Corruption Layer
- Hl7 Integration
- Domain Modeling
Domain-Driven Design - 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.
- AnalysisSeniorNew
Diagnose and Fix Query-Planner Misestimates in a FinTech Warehouse
For each of the 6 queries, capture EXPLAIN (ANALYZE, BUFFERS) and compare estimated vs actual rows at each node. Identify the misestimate source per query (single-column stats s…
- Query Optimization
- Postgresql Planner
- Extended Statistics
Advanced Database Systems - CodeIntermediateNew
Build an Indexer for an On-Chain DeFi Analytics Product
Receive the 6 protocols' ABIs + the team's required event coverage spec (around 40 event types). Build a TypeScript indexer using viem + Postgres: subscribe to new blocks via We…
- Blockchain Indexing
- Typescript
- Ethereum
Blockchain and Decentralized Systems Engineering - 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 - CodeIntermediateNew
Apply Hexagonal Architecture to a Payments Microservice
Design the settlement domain in pure Kotlin (no Spring imports, no framework annotations). Define ports for: payment-network adapter (one inbound per network — SEPA, Faster Paym…
- Hexagonal Architecture
- Ports And Adapters
- Kotlin Programming
Domain-Driven Design 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
- CodeIntermediateNew
Reason over a Climate Policy Knowledge Graph for an EU Think Tank
Design a knowledge graph schema covering regulations, member states, sectors, transposition dates, and source-document citations. Ingest a curated dataset of around 200 nodes th…
- Knowledge Graphs
- Knowledge Representation
- Rule Based Reasoning
Artificial Intelligence: Principles and Techniques - CodeIntermediateNew
Migrate a Legacy Warehouse to a Lakehouse for an Edtech AI Platform
You receive a Postgres dump of around 50 GB and the current dbt models that produce the student-attempts mart. Land the raw data in object storage (S3 or GCS) as Parquet partiti…
- Lakehouse Architecture
- Delta Lake
- Spark
Data Engineering and Big Data Systems - DesignFoundationalNew
Redesign a Vet-Clinic SaaS Database to Third Normal Form
Using the current schema dump and the eight most-common reporting queries provided to you, design a replacement database structure for VetLedger. First, produce an entity-relati…
- Data Modeling
- Normalization
- SQL
Open coursework - AnalysisBeginnerNew
Audit Data Quality for a Climate Tech Sensor Network
You receive 30 days of ingested sensor data (around 400 million rows) plus the sensor inventory and known maintenance windows. Define a set of data-quality expectations (null ra…
- Data Quality
- Great Expectations
- Anomaly Detection
Data Engineering and Big Data Systems - DesignSeniorNew
Designing a Data Warehouse for a Renewable Energy Firm
You are given sample data from three sources: energy production logs, weather data, and equipment maintenance records. Your task is to: (1) design a star schema with fact and di…
- Data Warehousing
- Star Schema
- Etl
Database Systems - StrategyIntermediateNew
Decompose a CRM Monolith into Bounded Services
Analyze the monolith using NDepend or similar (provided). Identify the top 4-6 candidate service boundaries based on coupling + business-capability seams (likely: Quotation, Pol…
- Strangler Fig Pattern
- Service Decomposition
- Csharp Programming
Enterprise and Business Software Engineering - CodeBeginnerNew
GPU Cost Dashboard for an AI Consulting Practice
Pull AWS Cost and Usage Report, GCP billing export, and Lambda Labs invoices into a single Parquet table. Implement a tagging convention (project + client + experiment_id) and a…
- Cloud Cost Attribution
- Etl Pipelines
- Data Modeling
Cloud Computing for Data and ML - CodeBeginnerNew
Design a Domain Model for a Library Loan System (Java)
Implement, in Java 21, an Item type hierarchy (Book, AudioBook, Periodical, EquipmentLoan — each with sub-type-specific rules), Member with eligibility logic, Loan as an aggrega…
- Java
- Oo Design
- Domain Modeling
Object-Oriented Programming and Design - ResearchSeniorNew
SAT-Based Planner for Smart-Grid Demand Response
Encode the dispatch problem (which customers to curtail by how much, respecting per-customer contractual caps and grid-cell totals) as a SAT or MaxSAT instance. Solve 50 histori…
- Sat Based Planning
- Constraint Encoding
- Benchmarking
Automated Planning - CodeIntermediateNew
Multi-Tenant SaaS Backend with Postgres Row Security
Design the multi-tenant schema: shared tables with a tenant_id column, indexed appropriately. Write a forward + backward migration (using Drizzle or Prisma). Implement Postgres …
- Multi Tenant Architecture
- Postgresql
- Row Level Security
Open coursework - CodeIntermediateNew
Hierarchical Plans for an Aerospace Maintenance Crew Scheduler
You receive a synthetic week of 80 work orders with hierarchical decompositions, technician certifications, and shared-tool constraints. Implement an HTN planner (PyHOP or HDDL …
- Htn Planning
- Domain Modeling
- Constraint Handling
Automated Planning - CodeIntermediateNew
Build a Feature Store Backbone for a Healthtech ML Team
You receive synthetic wearable telemetry (heart rate, accelerometer, sleep stages) for around 5,000 patients across 90 days, plus the existing scattered feature scripts from the…
- Feature Engineering
- Data Modeling
- Python
Data Engineering and Big Data Systems
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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