Business
ESG, Sustainability & Impact Challenges
ESG, Sustainability & Impact challenges put you inside the work of measuring and disclosing how an organization affects the planet and society. You'll build on Climate Basics and ESG Frameworks, run a Materiality Assessment, and carry out GHG Protocol Scope 1 emissions accounting the way sustainability teams actually do.
From there you'll handle the harder edges — GHG Protocol Scope 2 & 3 accounting, CSRD / ISSB Disclosures, transition planning, and air-quality dispersion modeling — backing every claim with ESG data governance and audit-grade documentation, and mapping outcomes to the UN SDGs. Each challenge you solve earns a verified credential you can share with recruiters.
- AnalysisIntermediateNew
Penetration-Test the TLS Configuration of an Edge Fleet
Receive read-only access to a 50-node representative sample (anonymized). Scan with testssl.sh + Qualys SSL Labs (where reachable) + a custom Go tool you write to test specific …
- Tls
- Applied Cryptography
- Penetration Testing
Applied Cryptography - CodeBeginnerNew
Find and Exploit Web Vulnerabilities on a Capture-the-Flag Range
Receive credentials to the CTF environment, the 8 challenge specifications (each with a target endpoint and a flag to extract), and the Rails source for the vulnerable app. For …
- Web Security
- OWASP Top 10
- Penetration Testing
Introduction to Computer Security - 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 - CodeBeginnerNew
Implement Async Message-Passing for an IoT Gateway
Receive the current gateway source (Python 3.11, single-threaded paho-mqtt client + a serial HTTP forwarder, ~1,100 lines), a sensor-simulator that fans out 500 mock sensors at …
- Async Programming
- Message Passing
- Asyncio
Concurrent and Parallel Programming 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
- AnalysisIntermediateNew
Optimize a Slow Trino Query Over a Petabyte Warehouse
Receive the slow SQL query (around 600 lines), the Trino EXPLAIN ANALYZE output, the underlying Iceberg table schemas (partition specs, sort orders), and 30 days of execution me…
- Trino
- SQL Optimization
- Iceberg
Big Data and Data-Intensive Systems - CodeIntermediateNew
Build and Audit an ERC-20 Vesting Contract for a DeFi Startup
Implement an ERC-20 vesting contract with: per-beneficiary cliff (default 12 months) + linear vesting (default 36 months), revocable allocations (for founders only), pause funct…
- Solidity
- Smart Contracts
- Foundry
Blockchain and Decentralized Systems Engineering - ResearchSeniorNew
Audit a Custom Cryptographic Protocol
Read the 22-page protocol spec, the Go reference implementation (around 4,000 lines), and the test vectors. Run a structured review covering: primitive choices (which cipher, MA…
- Applied Cryptography
- Cryptographic Audit
- Protocol Analysis
Applied Cryptography - CodeBeginnerNew
Diagnose and Fix a Deadlock in a Multi-Threaded Payments Service
Receive the service source (Java 21 + Spring Boot, around 30,000 lines), 4 thread dumps from production deadlocks, and a load harness that reproduces the bug roughly 1 in 50 run…
- Deadlock Analysis
- Locks And Monitors
- Python Or Javascript
Concurrent and Parallel Programming - 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.
- DesignSeniorNew
Re-Architect a Data-Center Fabric for an AI-Training Workload
Receive the current 3-tier topology diagram, traffic captures from the existing fabric (4 weeks of sFlow), and the rack-level requirements for the 4 new H100 racks (200 Gbps per…
- Data Center Networking
- Bgp
- Evpn Vxlan
Advanced Computer Networks - StrategyBeginnerNew
ESG Strategy for a Fast-Growing D2C Cosmetics Brand
You are a junior ESG consultant hired by Glow & Green. Your task is to propose a governance mechanism (e.g., an ESG committee, board-level oversight, or stakeholder advisory pan…
- ESG Frameworks
- Stakeholder Mapping
- Governance Design
Corporate Governance - CodeIntermediateNew
Deploy SDN-Based Network Slicing for a Telco Operator
Receive the current transport architecture (P4-programmable switches, ONOS controller cluster), the 3 customer-class SLAs (consumer: best-effort 50 Mbps; enterprise IoT: 5 Mbps …
- Sdn
- Onos
- Mininet
Advanced Computer Networks - CodeIntermediateNew
Reproducible Patient-Cohort Analysis for a Pharma AI Vendor
You receive a written cohort definition (type-2 diabetes patients on metformin for at least 90 days, aged 40-70) and a target output: 12-month HbA1c change distribution plus a K…
- Reproducible Analysis
- Cohort Analysis
- Survival Analysis
Applied Data Analysis and Practical Data Science Get recognized by recruiters and employers.
Credentials are blockchain-anchored via LearnCoin — tamper-evident, portable, link-shareable on LinkedIn and beyond.
Why Ewance
- AnalysisIntermediateNew
Reverse-Engineer a 22-Year-Old COBOL Batch Pipeline
Use SonarQube + cobol-language tooling + JCL parsers to extract job dependencies and data-flow across the 140 jobs. Build a job-dependency graph (Graphviz). Run impact analysis:…
- Reverse Engineering
- Legacy Systems
- Dependency Analysis
Software Evolution and Maintenance - CodeBeginnerNew
Build a Bounded Concurrent Queue for a Microservice Worker Pool
Implement a bounded concurrent queue in Go (no third-party queue libraries; standard library + sync primitives only) that supports: Put(item) blocks when full, TryPut(item, time…
- Concurrent Data Structures
- Mutex And Condvar
- Systems Language Proficiency (Go, Rust, C++)
Concurrent and Parallel Programming - 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 Event Streaming
Big Data and Data-Intensive Systems - CodeIntermediateNew
Build a GitOps Rollout Pipeline with ArgoCD Progressive Delivery
Receive the current CI pipeline (GitHub Actions runs kubectl apply against EKS), one representative service (Go API, 8 replicas, 4ms p99 SLO, 0.1 percent error-rate SLO), and ac…
- Kubernetes Orchestration
- Gitops
- Argocd
Container Orchestration with Kubernetes - CodeBeginnerNew
Implement a User-Space Shell with Process and Signal Handling
Implement a shell in C (no shell helpers, just POSIX system calls). Required features: read a line, parse it into commands + arguments, handle pipelines with arbitrary chain len…
- System Calls
- Process Management
- Signal Handling
Computer Systems and Organization - DesignIntermediateNew
Migrate a 200TB Data Lake from Parquet to Iceberg
Receive an inventory of the 200TB hot tier (around 1,200 tables, around 38 PB of historical data referenced), the current Spark + Trino read patterns, and 6 months of schema-cha…
- Iceberg
- Parquet
- Data Lake
Big Data and Data-Intensive Systems - CodeBeginnerNew
End-to-End Lane Following on a Donkeycar Platform
Use the public Donkeycar Tub dataset (or collect about 30 minutes of driving on the simulator). Train a CNN-policy baseline (the Donkeycar default architecture is fine) that pre…
- End To End Learning
- Imitation Learning
- Pytorch Or Tensorflow
AI for Autonomous Vehicles - DesignBeginnerNew
Build a Wi-Fi 6E Site Survey for an Industrial IoT Deployment
Receive the warehouse floor plan (CAD + obstruction inventory), the AMR fleet's RF requirements (6 GHz preferred, -67 dBm minimum, <50ms handover), and the existing Wi-Fi 5 site…
- Wireless Networks
- Wifi 6e
- Site Survey
Advanced Computer Networks - 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 - CodeIntermediateNew
Implement Authenticated Encryption for a Document Service
Design the envelope-encryption hierarchy: customer Key Encryption Key (KEK) held in AWS KMS (Key Management Service), Data Encryption Keys (DEKs) wrapped per document. Use AES-2…
- Applied Cryptography
- Aead
- Key Management
Applied Cryptography - 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 Orchestration
- Network Policy
- Calico
Container Orchestration with Kubernetes - CodeBeginnerNew
Reverse-Engineer a Stripped Binary to Restore Linking Symbols
Receive the stripped shared object (Linux ELF, x86-64, ~280KB), a crash dump with 12 frames of indecipherable addresses, and 4 years of partial git history with some related (bu…
- Reverse Engineering
- Linking And Loading
- Machine Code
Computer Systems and Organization
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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