Computer Sciences Challenges
Explore computer science challenges on Ewance to equip yourself with job-relevant skills for a variety of roles. Learn programming techniques and build technical skills with challenges on software development, algorithm design, system architecture, and more.
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- CodeIntermediateNew
Implement Federated Learning for a Government Statistics Office
Use Flower as the FL framework. Simulate 8 municipalities each with a partition of a synthetic wage dataset (provided, 1M rows, EU-Labour-Force-Survey schema). Train a gradient-…
- Federated Learning
- Differential Privacy
- Python Programming
Privacy-Enhancing Technologies - CodeIntermediateNew
Build a CodeQL Query Pack to Catch Logging of Personal Data
Using the provided personal-data source and logging-sink specification, write CodeQL data-flow queries for Java and Python that detect personal data travelling from a source (re…
- Static Analysis
- Codeql
- Data Flow Analysis
Open coursework - CodeIntermediateNew
Find the Dead Code Hiding in a Python Monorepo
Build a dataflow- and call-graph-based dead-code detector in Python (using libcst, or the standard ast module together with jedi) and prove it on the materials provided. Run it …
- Dataflow Analysis
- Ast
- Call Graph
Open coursework - CodeIntermediateNew
Build a Shareable Immutable List for a Real-Time Document Editor
Using the provided API specification (persistent-list-spec) and the starter module (immutable-list-starter), implement a persistent immutable list supporting get, set, append, p…
- Data Abstraction
- Recursion
- Persistent Data Structures
Open coursework Practice your coursework on real scenarios.
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Why Ewance
- DesignIntermediateNew
Design an Invoice-Rules Mini-Language for Non-Technical Users
Design a rule mini-language whose grammar (written in Backus-Naur Form, the standard notation for describing grammars) covers boolean logic (and / or / not), comparison operator…
- Abstraction
- Recursion
- Domain Specific Language
Open coursework - CodeIntermediateNew
Bloom Filter Cache to Cut Origin Load at a CDN Edge
Given a target false-positive rate of 1 percent at 200 million keys per shard, compute the optimal bit-array size (m) and hash-function count (k) using the canonical formulas. I…
- Bloom Filters
- Probabilistic Data Structures
- Hash Functions
Randomized Algorithms - CodeIntermediateNew
MinHash Similarity Sketch for a Job-Board Deduplication Pipeline
Implement a MinHash signature generator (128 permutations) over shingled job-posting text (5-gram word shingles). Build an LSH banding index (16 bands of 8 hashes each) tuned fo…
- Minhash
- Locality Sensitive Hashing
- Probabilistic Data Structures
Randomized Algorithms - AnalysisIntermediateNew
Randomized Load Balancer with the Power of Two Choices
Simulate four placement policies on a 24-hour anonymized connection-establishment trace (around 4.1 billion events): (1) random-1, (2) round-robin, (3) P2C with instantaneous lo…
- Power Of Two Choices
- Load Balancing
- Randomized Algorithms
Open coursework - Browse challenges
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- CodeIntermediateNew
Reservoir Sampling for a Privacy-Preserving Telemetry Pipeline
Implement Vitter's Algorithm R (and the faster Algorithm L for bonus credit) producing a 90M-event uniform sample per day from a stream of 18B. Add per-key stratification (so lo…
- Reservoir Sampling
- Randomized Algorithms
- Streaming Systems
Open coursework - CodeIntermediateNew
Apply the Mikado Method to Untangle a Tax-Engine Class
Starting from the live codebase (Java 17, 73 percent line coverage), write a failing test that asserts the desired end state ('TaxCalculator is decomposed into per-country strat…
- Mikado Method
- Refactoring
- Strategy Pattern
Refactoring and Code Smell Detection - CodeIntermediateNew
Strangler-Fig Migration of a Monolithic Order Service
Stand up an HTTP facade in front of the monolith (Nginx or a small Go proxy) that routes by URL pattern. Slice 1: extract the order-status read endpoint, dual-write nothing, rou…
- Strangler Fig Pattern
- Refactoring
- Legacy Modernization
Refactoring and Code Smell Detection - CodeIntermediateNew
Stream-Process a 64-Microphone Array to Locate Bearing Faults in Real Time
Using the provided fixture generator and array-geometry spec, implement an overlap-add streaming pipeline that consumes 64 channels in 1,024-sample frames with 50 percent overla…
- Fft
- Signal Processing
- Beamforming
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Why Ewance
- AnalysisIntermediateNew
Capacity Planning Model for a Black-Friday Traffic Surge
Pull 18 months of per-service request rate + utilization from Prometheus. Forecast BFCM traffic per service using a baseline + multiplicative seasonal model (Prophet or statsmod…
- Capacity Planning
- Forecasting
- Autoscaling
Site Reliability Engineering - ResearchIntermediateNew
Design an Empirical Study of Pull Request Review Throughput
Using the provided pull request dataset and the stakeholder brief, design and run an empirical software-engineering study on review throughput. State three falsifiable hypothese…
- Empirical Software Engineering
- Software Analytics
- Statistical Analysis
Open coursework - CodeIntermediateNew
Ship an Engineering-Health Dashboard for an 18-Team Org
Using the four sample data extracts (pull-request events, Linear work-item history, PagerDuty incidents, and the quarterly developer-experience survey) and the organization brie…
- Software Analytics
- Dora Metrics
- Space Framework
Open coursework - AnalysisIntermediateNew
Diagnose a Failed Microservices Migration at a Travel Platform
Using only the four supplied materials — the interview transcript excerpts (voyalink-interview-transcripts), the decision and incident artifact corpus (voyalink-artifact-corpus)…
- Industrial Case Study
- Qualitative Research
- Software Architecture
Open coursework - 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 - CodeIntermediateNew
Refactor a Big-Ball-of-Mud Java Servlet Application
Week 1: install JUnit 5 + Testcontainers harness, write characterization tests for the 2 target workflows (PolicyIssue + ClaimSubmit) reaching at least 80 percent branch coverag…
- Refactoring
- Characterization Testing
- Legacy Systems
Software Evolution and Maintenance - CodeIntermediateNew
Strangler-Fig Modernization of a Healthcare Reporting Service
Audit the report categories (around 14) and pick operating-theater utilization for the pilot extraction (high volume, moderate complexity, low regulatory blast-radius). Design t…
- Strangler Fig
- Legacy Systems
- Feature Flags
Open coursework - DesignIntermediateNew
Build a Quality Metrics Program for a Medical-Device Software Team
Read the team's QMS (Quality Management System) documents and the IEC 62304 software lifecycle requirements. Design a metric catalog of 12-15 metrics covering process (review-co…
- Quality Metrics
- Iec 62304
- Process Improvement
Software Quality and Process Improvement - StrategyIntermediateNew
Roadmap a Defense Software Supplier from CMMI Level 2 to Level 3
Using only the materials provided to you — the de-identified Level 2 appraisal report (M1), the current-state process documentation snapshot (M2), the pilot baseline dataset for…
- Cmmi
- Process Improvement
- Process Models
Open coursework - CodeIntermediateNew
Secure the Software Supply Chain of an Open-Source SDK
Audit the current state: dependency tree, publish process, GitHub Actions workflows, signing posture. Generate an SBOM (CycloneDX format) using Syft. Run OpenSSF Scorecard and t…
- Supply Chain Security
- Slsa
- Sbom
Open coursework - AnalysisIntermediateNew
Secure-by-Design Review of a Microservices Auth Subsystem
Read the 18-page proposed auth-service design (Next.js BFF, FastAPI auth-service, Postgres for sessions + refresh, Redis for short-lived tokens, integration with Auth0 for OIDC)…
- Secure Design
- OWASP Asvs
- Oauth2
Software Security - CodeIntermediateNew
Real-Time Collaboration Whiteboard with WebSockets
Design the board state model (sticky notes + cursor positions) and pick a conflict-resolution approach (last-write-wins for v1, or operational-transform if scoping allows). Buil…
- Websockets
- React
- Nodejs
Open coursework
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Browse challenges aligned to your studies.
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Accept the one that fits your goals.
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