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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- StrategyBeginnerNew
Introduce XP Practices to a Legacy E-Commerce Codebase
Run a 6-week intervention with the 7-person checkout team. Week 1: baseline (current test coverage, defect-escape rate, story cycle time). Weeks 2-5: introduce TDD on all new co…
- Extreme Programming
- Test Driven Development
- Pair Programming
Agile Methods and Practices - CodeFoundationalNew
Diagnose and Rebuild a Slow Recipe Search at a Marketplace Startup
Work only from the three items in the provided materials: the current search function, a representative sample of the recipe catalog, and the fixed set of representative queries…
- Algorithm Analysis
- Big O
- Data Structures
Open coursework - DesignBeginnerNew
Greedy Delivery-Slot Assignment for a Munich Grocery Startup
Using the provided order history sample, rider roster, and manual dispatch baseline, design and implement a greedy slot-assignment algorithm in Python. The algorithm must (1) so…
- Greedy Algorithms
- Algorithm Analysis
- Python
Open coursework - CodeIntermediateNew
Ship a Knapsack Battery Allocator for Farm Sensors
Using the device specification (device-spec), the sensing-mode table (sensing-modes), the month of simulated farm days (simulated-farm-days), and the reference greedy heuristic …
- Dynamic Programming
- Algorithm Analysis
- C Programming
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- CodeBeginnerNew
Design an Effort-Aware Bike Routing Feature for Lisbon
Working only from the provided materials — the Lisbon street-graph edges (lisbon-bike-graph), the matching node coordinates and elevations (lisbon-graph-nodes), the 50 origin-de…
- Graph Algorithms
- Dijkstra
- Algorithm Analysis
Open coursework - AnalysisBeginnerNew
Is the Optimal Vet-Scheduling Feature Computationally Tractable?
Working only from the materials provided — the product feature specification, the de-identified internal record of the customer request, a representative one-day appointment dat…
- Np Completeness
- Complexity Theory
- Algorithm Analysis
Open coursework - CodeSeniorNew
Min-Cost Max-Flow for Cloud Workload Placement
Receive 30 days of anonymized placement requests (workload CPU/memory shape, affinity rules), zone capacity per day, and cross-zone bandwidth costs. Model the placement as a min…
- Network Flows
- Algorithm Analysis
- Graph Algorithms
Advanced Algorithms - DesignSeniorNew
Provably Fair Approximation Algorithm for a Neobank On-Call Roster
Using the roster problem specification (roster-problem-spec), formalize the weekly on-call assignment as a constrained multi-week optimization problem, prove it is NP-hard by re…
- Approximation Algorithms
- Linear Programming
- Np Completeness
Open coursework - Browse challenges
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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.
- AnalysisSeniorNew
Amortized-Analysis Investigation of a Production Telemetry Cache
Working only from the three provided materials — the de-identified incident record (incident-record), the representative cache source module (cache-source), and the recorded ope…
- Amortized Analysis
- Data Structures
- Algorithm Analysis
Open coursework - CodeIntermediateNew
Implement and Tune HyperLogLog for Trace-Stream Cardinality in Go
Working from the HyperLogLog paper (provided as a real source) and the provided representative trace sample, implement HyperLogLog from scratch in Go with no third-party algorit…
- Randomized Algorithms
- Sketching
- Algorithm Analysis
Open coursework - AnalysisIntermediateNew
Spectral Clustering Proposal for Customer Segmentation at Cadence
Using the provided customer usage sample, construct a similarity graph (k-nearest-neighbors with k=15 and Gaussian radial-basis-function edge weights), compute the normalized gr…
- Spectral Methods
- Linear Algebra
- Algorithm Analysis
Open coursework - CodeIntermediateNew
Build a GraphQL Federation Schema for an E-Commerce Platform
Receive the existing 22 REST endpoints' OpenAPI specs and a list of 5 priority subgraphs. Design a federated GraphQL schema using Apollo Federation v2 directives (@key, @externa…
- Graphql
- Graphql Federation
- API Design
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- CodeIntermediateNew
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
Open coursework - CodeIntermediateNew
Prove a gRPC Migration for a Kubernetes Control-Plane API
Examine three things: the captured control-plane traffic record (`traffic-7d`), the current REST API specification (`openapi-spec`), and the representative Go service module (`g…
- Grpc
- Protobuf
- API Design
Open coursework - CodeIntermediateNew
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 - CodeSeniorNew
Implement Threshold Signatures for a Multi-Sig Custody Service
Read the FROST IETF draft (draft-irtf-cfrg-frost) and the underlying Schnorr signature scheme on the secp256k1 curve. Implement the FROST distributed key generation (DKG) and 3-…
- Applied Cryptography
- Threshold Signatures
- Rust
Open coursework - CodeIntermediateNew
Build a Real-Time Streaming Pipeline for Card-Fraud Scoring
Using the provided transaction-event sample, the cardholder feature snapshot, the reference scoring service, and the risk team's experiment specification, build a stream-process…
- Stream Processing
- Kafka
- Flink
Open coursework - CodeIntermediateNew
Design a Change-Data-Capture Pipeline for an E-Commerce Reseller
Receive the MySQL schema (220 tables), 7 days of binlog samples, and the data team's freshness + correctness requirements. Design the CDC pipeline: Debezium for MySQL binlog cap…
- Change Data Capture
- Debezium
- Kafka
Big Data and Data-Intensive Systems - 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 - CodeSeniorNew
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
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 - CodeBeginnerNew
Containerize a Legacy Java Monolith and Move It to AWS ECS
Working only from the supplied materials — a representative module of the quoting application (`quote-engine-module`), a snapshot of the current web-server and routing configura…
- Containerization
- Docker
- AWS
Open coursework - 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
- Terraform
Cloud Computing - DesignIntermediateNew
Stand Up a Self-Service Developer Platform on Backstage
Read the company case file, the squad-and-service inventory, and the Platform v1 postmortem, and consult the official Backstage software-templates documentation for the mechanic…
- Internal Developer Platform
- Backstage
- Terraform
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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