Documentation
If you like applying Documentation, every challenge here gives you a chance to practice it on a real industry brief.
- CodeAdvancedNew
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 - CodeExpertNew
Profile and Tame a P99-Latency Tail for an Ad-Auction Service
Receive the bidder source (Go, around 22,000 lines), production traces (eBPF + flame graphs from 30 minutes of peak traffic), and the host config (NUMA-2 socket, 96 cores, 384GB…
- Performance Optimization
- Ebpf
- Go
Performance Engineering of Software Systems - AnalysisAdvancedNew
Cost-Profile a Spark Job at Scale and Cut the Bill in Half
Receive the PySpark job (around 1,800 lines), 5 nights of Spark UI + EMR metrics, and the EMR cluster config. Profile to find the top 3 cost drivers (likely candidates: skewed j…
- Spark
- Cost Optimization
- Etl Pipelines
Big Data and Data-Intensive Systems - CodeAdvancedNew
Migrate Stateful Workloads to StatefulSets with Storage Class Tuning
Receive the current Redis Sentinel topology (3 nodes, ~120GB data), the EBS gp3 baseline performance requirements (3,000 IOPS, 125 MB/s), and the cluster (EKS 1.29 with the EBS …
- Kubernetes
- Statefulsets
- Storage Classes
Container Orchestration with Kubernetes Practice your coursework on real scenarios.
Every challenge is shaped from real industry context — not generic exercises. The work mirrors what your degree prepares you for.
Why Ewance
- DesignExpertNew
Design a Cross-Chain Bridge Protocol with Honest Threat Model
Read the Vitalik 'cross-chain interoperability' essay and survey 3 existing bridge designs (lock-and-mint, atomic-swap, optimistic-rollup-native). Design your protocol around a …
- Blockchain Protocols
- Smart Contracts
- Solidity
Blockchain and Decentralized Systems Engineering - CodeIntermediateNew
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 - AnalysisAdvancedNew
Diagnose Modern Transport-Protocol Performance for an OTT Streamer
Receive the current delivery architecture (HTTP/2 origin + CDN), 4 weeks of Conviva-style QoE (quality of experience) metrics, and access to a synthetic-client harness (Linux + …
- Quic Http3
- Network Measurement
- Transport Protocols
Advanced Computer Networks - CodeAdvancedNew
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 - 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.
- DesignAdvancedNew
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
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 - DesignExpertNew
Design an End-to-End Encrypted Messaging Protocol
Read the Signal protocol specifications (X3DH, Double Ratchet) and the team's current architecture (server-stored unencrypted messages). Design an E2EE protocol covering: identi…
- Applied Cryptography
- Protocol Design
- Rust
Applied Cryptography - CodeIntermediateNew
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 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
- AnalysisAdvancedNew
Run a Red-Team Exercise on a Cloud-Native Microservices Platform
Receive a scoped engagement letter (in-scope: 6 microservices and their CI/CD pipelines; out-of-scope: customer-data exfiltration beyond proof-of-access), the architecture diagr…
- Red Teaming
- Kubernetes Security
- Lateral Movement
Computer Systems Security - DesignIntermediateNew
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 - CodeIntermediateNew
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 - StrategyIntermediateNew
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 - DesignAdvancedNew
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 - AnalysisAdvancedNew
Cost-Optimize a Misshapen Kubernetes Cluster
Receive 30 days of cluster metrics (Prometheus + AWS Cost Explorer exports), Helm releases, and PodDisruptionBudgets per namespace. Profile: identify the top 3 cost drivers (lik…
- Kubernetes
- Cost Optimization
- Aws
Cloud Computing - AnalysisAdvancedNew
Diagnose a Memory-Hierarchy Bottleneck in a Trading-System Hot Path
Receive the normalizer source (around 4,000 lines of C++17), a replay harness that feeds 30 minutes of recorded market data, and host-machine specifications (Intel Xeon Gold 634…
- Memory Hierarchy
- Performance Profiling
- Perf
Computer Systems and Organization - CodeIntermediateNew
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 - AnalysisAdvancedNew
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 - CodeAdvancedNew
Build a Self-Service Internal Developer Platform on Backstage
Stand up a Backstage instance (Docker-Compose for local, EKS for prototype hosting). Build 3 software templates: (1) New Go microservice (repo + CI + ECS service + Terraform + b…
- Internal Developer Platform
- Backstage
- Terraform
Cloud Computing - CodeAdvancedNew
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
- Gitops
- Argocd
Container Orchestration with Kubernetes - CodeIntermediateNew
Build a Secure-Coding Linter Ruleset for a Backend Team
Receive the last 12 security-review findings, 3 representative repos (Node.js + TypeScript), and access to a CI pipeline (GitHub Actions). Build a custom Semgrep ruleset (or ESL…
- Secure Coding
- Static Analysis
- Semgrep
Introduction to Computer Security
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.
Industry teams behind a decade of practitioner briefs
Hiring from this pool?
Sponsor a challenge and meet candidates through actual work.
Industry teams can shape briefs around the skills they hire for, then evaluate students on rubric-scored deliverables — not resumes.