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
- 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 - CodeIntermediateNew
Tame Lock Contention on a Shared Property-Manager CRM Database
Working only from the four provided materials, produce a fix-and-prove package. Start with the recorded lock snapshots (lock_snapshots) and the environment case file (db_environ…
- Concurrency Control
- Lock Contention
- Postgresql
Open coursework - DesignIntermediateNew
Design a Real-Time Order Pipeline for a Fintech Payments Platform
You receive a synthetic Kafka stream of around 500 transactions per second, a static merchant dimension table (about 80,000 rows), and a daily FX rate snapshot. Design an end-to…
- Streaming Data
- Kafka
- Stream Processing
Data Engineering and Big Data Systems - 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 Develop in-demand professional skills.
Each challenge names the skills it strengthens. Over time, your profile fills with the competences a hiring manager would actually look for.
Why Ewance
- AnalysisBeginnerNew
Plan and Validate a MySQL-to-PostgreSQL Records Migration
Using the de-identified case record (incident-file-records-office), the representative schema export (mysql-schema-sample), and the anonymized staging extract (staging-records-s…
- Database Migration
- Mysql
- Postgresql
Open coursework - AnalysisBeginnerNew
Index a Slow 90-Million-Row FinTech Reporting Database
Your analysis task is to read the engineering ticket and the six reporting queries in the case file (M1), study the transactions table definition, column statistics, and write w…
- Indexing
- Query Optimization
- Explain Analyze
Open coursework - CodeIntermediateNew
Design an Event-Sourced Inventory System for a Third-Party Warehouse
Working from the operations case file and the warehouse domain specification, design an event model of twelve to fifteen events that covers the warehouse lifecycle (receive, put…
- Event Sourcing
- Cqrs
- Eventstoredb
Open coursework - 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 - Browse challenges
Explore role
Strategy Analyst
Frame the business question, model the options, build the recommendation. From market sizing to competitive analysis, this role is where strategy consulting meets in-house decision-making.
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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