Audit-grade documentation
If you like applying Audit-grade documentation, every challenge here gives you a chance to practice it on a real industry brief.
- 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 - DesignIntermediateNew
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 Event Streaming
- Flink
Performance Engineering of Software Systems - 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
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 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
- 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 - AnalysisIntermediateNew
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…
- Apache Spark
- Finops & Cost Optimization
- Etl Pipelines
Big Data and Data-Intensive Systems - 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 Or Azure
- Terraform
Cloud Computing - DesignSeniorNew
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 - Browse challenges
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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.
- AnalysisBeginnerNew
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 - 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 - 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 - AnalysisIntermediateNew
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 Orchestration
- Finops & Cost Optimization
- AWS Or Azure
Cloud Computing 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
- 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 - AnalysisIntermediateNew
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 - DesignSeniorNew
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
- Systems Language Proficiency (Go, Rust, C++)
Applied Cryptography - 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 Or Javascript
- Multiprocessing
Concurrent and Parallel Programming - 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 - CodeBeginnerNew
Tune Autoscaling for a Cost-Sensitive Workload with HPA + KEDA
Receive the service's current Deployment + HorizontalPodAutoscaler config (static 12-20 replicas), 90 days of traffic logs + Kafka-lag metrics, and the SLA (p99 < 250ms, error r…
- Kubernetes Orchestration
- Autoscaling
- Keda
Container Orchestration with Kubernetes - 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 Or Azure
Cloud Computing - CodeBeginnerNew
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 - 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
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 - CodeBeginnerNew
GPU Cost Dashboard for an AI Consulting Practice
Pull AWS Cost and Usage Report, GCP billing export, and Lambda Labs invoices into a single Parquet table. Implement a tagging convention (project + client + experiment_id) and a…
- Cloud Cost Attribution
- Etl Pipelines
- Data Modeling
Cloud Computing for Data and ML - 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). …
- REST API Design
- REST API Design
- API Versioning
API Design and GraphQL
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
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