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.
Recommended Challenges
· Audit-grade documentation Clear- 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
- API Design
- Documentation
API Design and GraphQL - 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
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 - 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 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
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 - CodeBeginnerNew
Design a Race-Free Cache for a Read-Heavy Service
Implement a thread-safe LRU-bounded cache in Java (or Go — your choice, defend it) with: read-write lock or copy-on-write semantics, get-or-load pattern with single-flight to de…
- Concurrent Data Structures
- Race Conditions
- Single Flight
Concurrent and Parallel Programming - StrategyBeginnerNew
Strategy Brief on Layer-2 Choice for a Web3 Gaming Studio
Survey the three L2 categories with 2026-current numbers: per-transaction cost at expected game throughput (around 50 TPS sustained, 500 TPS event spikes), finality latency (mat…
- Layer 2 Protocols
- Blockchain Protocols
- Research
Blockchain and Decentralized Systems Engineering - CodeBeginnerNew
Containerize a Legacy Java Monolith and Deploy to ECS
Receive the Java 8 monolith source (around 320k lines), the current Tomcat + Apache HTTPD config, and 30 days of production traffic logs. Containerize the application (multi-sta…
- Containerization
- Docker
- AWS
Cloud Computing - 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
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 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 - DesignSeniorNew
Multi-Region Active-Active Architecture for a Gaming Backend
Read the current architecture (single-region: ECS + RDS Aurora + Redis + S3) and traffic mix (around 60 percent APAC, 25 percent NA, 15 percent EU). Design a 3-region active-act…
- Multi Region Architecture
- AWS
- Terraform
Cloud Computing - CodeSeniorNew
Implement a Proof-of-Stake Consensus Mechanism in Rust
Read the Casper FFG paper (Buterin + Griffith, 2017) and design a simplified PoS implementation in Rust: 21 validators, 32-slot epochs, two-phase finality (justify, then finaliz…
- Consensus Algorithms
- Blockchain Protocols
- Rust
Blockchain and Decentralized Systems Engineering 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
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 - 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
- Go
Concurrent and Parallel Programming - 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 - CodeIntermediateNew
Build a Custom Kubernetes Operator for a Multi-Tenant SaaS
Receive the current Helm + bash setup, a description of the per-tenant resources to manage, and the cluster details (EKS 1.29, Strimzi for Kafka). Design a TenantPipeline CRD wi…
- Kubernetes Operators
- Crds
- Kubebuilder
Container Orchestration with Kubernetes - CodeFoundationalNew
Parallelize an Image-Processing Pipeline with Data Parallelism
Receive the current pipeline (Python 3.12, ~600 lines, uses Pillow + ffmpeg), a representative batch (1,000 images averaging 3MB each), and host specs (16 cores, 32GB RAM). Rewr…
- Data Parallelism
- Python
- Multiprocessing
Concurrent and Parallel Programming - 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 - 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
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
AI for Autonomous Vehicles - AnalysisBeginnerNew
Audit Encryption Choices for an E-Commerce Checkout Stack
Receive the architecture diagram (Next.js on Vercel, PostgreSQL on a managed service, Stripe-equivalent processor, Redis sessions), the TLS configurations for each public endpoi…
- Cryptography
- Tls
- Pci Dss
Introduction to Computer Security - 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 - 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
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
- Java
Concurrent and Parallel Programming
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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