Documentation
If you like applying Documentation, every challenge here gives you a chance to practice it on a real industry brief.
- DesignAdvancedNew
Build a Scalable-System-Design Spec for a Streaming-Ingest Pipeline
Receive the current architecture (Kafka 3.6, Flink 1.18, ClickHouse 24.x), 4 weeks of production metrics (per-topic throughput, partition skew, Flink operator backpressure, Clic…
- Scalable System Design
- Kafka
- Flink
Performance Engineering of Software Systems - DesignAdvancedNew
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 - CodeAdvancedNew
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 - DesignIntermediateNew
Architecture Decision Records for a Modernization Program
Read 18 weeks of architecture-channel Slack history and 6 architecture-review meeting notes to inventory decisions already made. Backfill 12 ADRs using Michael Nygard's template…
- Architecture Decision Records
- Technical Debt
- Stakeholder Communication
Technical Debt Management 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
- CodeAdvancedNew
Instrument Network Telemetry for an ISP's Backbone
Receive the backbone topology (12 routers across 4 PoPs, mix of Cisco IOS XR + Juniper Junos), the current SNMP-based monitoring stack, and 4 weeks of customer-complaint tickets…
- Network Telemetry
- Gnmi
- Kafka
Advanced Computer Networks - CodeExpertNew
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 - CodeIntermediateNew
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 - CodeIntermediateNew
Build an I/O Benchmarking Harness for an Edge Storage Appliance
Receive the appliance specs (4x 7.68TB Gen4 NVMe, ZFS, Linux kernel 5.15), the 3 target workload profiles (4KB random read at QD32, 1MB sequential write at QD8, mixed 70/30 read…
- Io Benchmarking
- Fio
- System Calls
Computer Systems and Organization - Browse challenges
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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.
- CodeAdvancedNew
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 - AnalysisIntermediateNew
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 - AnalysisIntermediateNew
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
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 Get recognized by recruiters and employers.
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Why Ewance
- ResearchExpertNew
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 - CodeAdvancedNew
Apply Software Transactional Memory to a Real-Time Auction Book
Implement two variants of the same auction-book API (best-bid/best-ask lookup, place-order, cancel-order, match-orders): (1) baseline with java.util.concurrent locks + a SkipLis…
- Transactional Memory
- Concurrent Data Structures
- Haskell
Advanced Concurrency and Parallel Computing - AnalysisAdvancedNew
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 - DesignIntermediateNew
Design-System Component Library in Figma for a Travel Brand
Audit the existing app across the 7 squads to inventory every variant of each component (screenshot grid). For the 12 priority components, design canonical variants using Figma …
- Design Systems
- Figma
- Component Libraries
User Interface Design and Prototyping - CodeAdvancedNew
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
Threat-Model a Patient-Intake Web App for a Telemedicine Startup
Receive the architecture diagram (Next.js front-end, Node.js API, PostgreSQL, S3 for ID-photo uploads, Clerk for auth), the data-flow description for patient intake, and the SOC…
- Threat Modeling
- Stride
- Risk Assessment
Introduction to Computer Security - CodeAdvancedNew
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 - AnalysisIntermediateNew
Profile and Optimize a Virtual-Memory-Heavy Image Pipeline
Receive the Go pipeline source, a representative batch (1,200 photos averaging 12MB each, with 30 outliers over 80MB), and host specs (4-core, 16GB RAM, Linux kernel 5.15). Run …
- Virtual Memory
- Performance Profiling
- Memory Hierarchy
Computer Systems and Organization - AnalysisAdvancedNew
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 - DesignExpertNew
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 - DesignExpertNew
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 - CodeIntermediateNew
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
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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