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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- AnalysisIntermediateNew
Map Knowledge Diffusion Across an Open-Source Project Ecosystem
Using the de-identified contributor activity export (material 1), build a temporal contributor-project network from the recorded events, then collapse it into a contributor-to-c…
- Network Science
- Temporal Networks
- Graph Analysis
Open coursework - CodeIntermediateNew
Roll Out OpenTelemetry Tracing Across a Microservices Fintech
Receive an anonymized service map (90 services, payment-critical path of 12), a runtime mix (Node.js, Go, Java), and existing logging/metrics setup. Define: an OTel SDK adoption…
- Distributed Tracing
- Opentelemetry
- Sampling Strategies
Software Observability - DesignIntermediateNew
Design a SLSA-Aligned, Signed Release Pipeline for an Apache Project
Working only from the materials provided—the project dossier, the current release-pipeline module, the SLSA v1.0 specification, the slsa-github-generator project, the Sigstore d…
- Supply Chain
- Slsa
- Sigstore
Open coursework - CodeIntermediateNew
Build a User-Space File System with FUSE for a Storage Startup
Build a FUSE driver (your choice of Rust + fuser crate or Go + bazil/fuse) that proxies POSIX operations to the startup's existing S3-compatible REST API (mock provided). Suppor…
- File Systems
- Fuse
- Rust Programming
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- AnalysisIntermediateNew
Choose the Right Tenant Containment Strategy for an Edge Platform
Working only from the provided materials, reach and defend a containment recommendation. Read the documented incident record (case-file) to understand what triggered the review …
- Containment
- Virtualization
- Wasm
Open coursework - CodeIntermediateNew
Parallelize a Monte Carlo Risk Engine for a Quant Fund
Starting from the provided single-threaded C++ engine module (engine_scalar.cpp) and the provided benchmarking and equivalence specification (parallelization-spec), profile the …
- Parallel Algorithms
- Shared Memory
- Work Stealing
Open coursework - CodeIntermediateNew
GPU-Parallel Graph Coloring for an EDA Tools Vendor
Implement Jones-Plassmann graph coloring in CUDA (or HIP if AMD hardware available). Input: a 12-million-node graph in CSR format (compressed sparse row). Output: a valid colori…
- Parallel Algorithms
- Gpu Programming
- Cuda
Parallel and Distributed Algorithms - CodeIntermediateNew
Stand Up a Backstage Developer Portal for a Frankfurt Fintech
Using the provided service inventory, ownership map, and rollout brief, build and deploy a Backstage portal on the company's existing Kubernetes platform and populate its catalo…
- Backstage
- Platform Engineering
- Service Catalog
Open coursework - Browse challenges
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Pricing Strategist
Set the price that captures value without leaving sales on the table. Demand modelling, willingness-to-pay research, and the disciplined experimentation that turns pricing into a competitive advantage.
- CodeIntermediateNew
Design a Multi-Tenant Kubernetes Namespace-Provisioning Self-Service
Design and build a Backstage scaffolder that lets a squad request a namespace (specifying environment, owners, expected scale). The scaffolder generates a pull request to a GitO…
- Platform Engineering
- Kubernetes
- Self Service
Platform Engineering - CodeIntermediateNew
Add Differential Privacy to a Mental-Health App's Analytics Dashboard
Wrap the analytics module in `analytics_module.py` (provided) with a differential-privacy layer built on OpenDP. Implement epsilon-delta accounting: add Laplace noise to counts …
- Differential Privacy
- Privacy Budget
- Python Programming
Open coursework - 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
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Why Ewance
- 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 - 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 - 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
Multi-Tenant Schema Migration for a Series-B HR SaaS
Design a 4-phase migration: (1) add new columns + tables, dual-write on every workflow mutation, (2) backfill 3.4 TB in chunks of around 50k rows per minute with throttling and …
- Multi Tenant Architecture
- Schema Migration
- Dual Write
Open coursework - CodeIntermediateNew
Build a Metered-Billing System for a Usage-Based SaaS
Build an event-ingest API (Express + Redis Streams) that receives usage events with idempotency keys. Aggregate hourly into Postgres rollups using a windowed worker that survive…
- Metered Billing
- Idempotency
- Event Aggregation
Open coursework - CodeIntermediateNew
Halve the Inner Solver in a Crash-Simulation Pipeline
Using the public structural finite-element matrices declared in `structural-matrices` as stand-ins for three production mesh sizes, benchmark four combinations: (1) GMRES with i…
- Sparse Linear Algebra
- Krylov Methods
- Preconditioning
Open coursework
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