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
- Ai Pair Programming
Agile Methods and Practices - CodeFoundationalNew
Optimize a Slow Search Function for a Recipe Marketplace
Receive the current Python function (nested loop over (recipe_title, ingredient_list) pairs), the 400k-row dataset (CSV), and 20 representative queries. Step 1: write up the cur…
- Algorithm Analysis
- Big O
- Functions & Data Structures
Algorithm Design and Analysis - CodeBeginnerNew
Greedy Algorithm for Delivery-Slot Assignment
Receive 14 days of order data (around 4,800 orders) with timestamps, addresses (already geocoded), and slot preferences, plus rider rosters with shift starts, ends, and max work…
- Greedy Algorithms
- Algorithm Analysis
- Python Or Javascript
Algorithm Design and Analysis - CodeIntermediateNew
Dynamic Programming for an IoT Battery Allocator
Read the device spec (32 KB RAM, 200 mAh daily budget, 9 sensing modes with mAh cost and farmer-value scores) and formulate the daily allocation as a 0/1 knapsack DP (dynamic pr…
- Dynamic Programming
- Algorithm Analysis
- C Programming
Algorithm Design and Analysis 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
- CodeBeginnerNew
Shortest-Path Routing for a Bike-Share Operator
Receive the graph (nodes with lat/lon/elevation, edges with length and slope) and 50 origin-destination test pairs. Implement Dijkstra's algorithm with a custom edge-weight func…
- Graph Algorithms
- Dijkstra
- Algorithm Analysis
Algorithm Design and Analysis - ResearchBeginnerNew
NP-Completeness Investigation of a Scheduling Feature Request
Read the feature spec (around 30 vets per clinic, around 10 rooms, around 200 appointments per day, vet-skill constraints, room-equipment constraints, customer-time preferences)…
- Np Completeness
- Complexity Theory
- Algorithm Analysis
Algorithm Design and Analysis - 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 - ResearchSeniorNew
Approximation Algorithm for an SRE On-Call Roster
Formulate the roster as a constrained multi-week assignment problem. Show it's NP-hard via reduction. Design a deterministic constant-factor approximation (likely candidate: an …
- Approximation Algorithms
- Linear Programming
- Np Completeness
Advanced Algorithms - 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.
- AnalysisIntermediateNew
Amortized-Analysis Investigation of a Production Cache
Read the C++ cache source (around 1,800 lines, custom open-addressing with periodic resize-and-rehash). Perform amortized analysis using all three methods (aggregate, accounting…
- Amortized Analysis
- Functions & Data Structures
- Algorithm Analysis
Advanced Algorithms - CodeIntermediateNew
Randomized Sketch Algorithm for Stream Cardinality
Read the HLL paper (Flajolet et al., 2007) and a sample of 30 minutes of customer trace IDs (around 80M events). Implement HLL from scratch in Go (no library imports). Run bench…
- Randomized Algorithms
- Sketching
- Algorithm Analysis
Advanced Algorithms - AnalysisIntermediateNew
Spectral Clustering for Customer Segmentation at a SaaS
Receive a 12,000 customer × 220 feature usage matrix (counts per feature per week, averaged over 12 weeks). Construct a similarity graph (k-nearest-neighbors with k=15, Gaussian…
- Spectral Methods
- Linear Algebra
- Algorithm Analysis
Advanced Algorithms - 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), …
- REST API Design
- Idempotency
- Webhooks
API Design and GraphQL 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
- CodeIntermediateNew
Migrate an Internal Service from REST to gRPC
Receive the existing OpenAPI spec, the Go service code, and 7 days of traffic data. Pick the top 2 RPS-by-method endpoints and design Protocol Buffers (protobuf) message + servi…
- Grpc
- Protobuf
- REST API Design
API Design and GraphQL - 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 - 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
- Systems Language Proficiency (Go, Rust, C++)
Applied Cryptography - AnalysisIntermediateNew
Penetration-Test the TLS Configuration of an Edge Fleet
Receive read-only access to a 50-node representative sample (anonymized). Scan with testssl.sh + Qualys SSL Labs (where reachable) + a custom Go tool you write to test specific …
- Tls
- Applied Cryptography
- Penetration Testing
Applied Cryptography - 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
- Systems Language Proficiency (Go, Rust, C++)
Blockchain and Decentralized Systems Engineering - 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 - CodeIntermediateNew
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 - CodeBeginnerNew
Add Constant Folding and Dead Code Elimination to a Toy Compiler
Fork the repo, read the IR specification (3-address code, register-based, documented in /docs/ir.md). Implement constant folding as an IR-to-IR pass: any operation on literal op…
- Intermediate Representation
- Constant Folding
- Dead Code Elimination
Compiler Construction - CodeIntermediateNew
Design Error Recovery for a Friendly Compiler
Read the existing parser (recursive-descent, in Rust). Design and implement a panic-mode error recovery strategy with synchronization tokens (statement boundary, end of block, s…
- Error Recovery
- Recursive Descent Parsing
- Diagnostic Design
Compiler Construction - CodeIntermediateNew
Compile a Subset of C to WebAssembly
Define a documented C subset: int and bool types, locals, if/else, while, function calls, return. Build a compiler in any host language (TypeScript or Rust preferred) that produ…
- Code Generation
- Webassembly
- Intermediate Representation
Compiler Construction - CodeIntermediateNew
Implement an SSA-Based Sparse Conditional Constant Propagation Pass
Read the IR specification (SSA form, phi nodes, typed values). Implement SCCP as a single combined worklist algorithm operating on the SSA lattice (top / constant / bottom) and …
- Static Single Assignment
- Dataflow Analysis
- Constant Propagation
Advanced Compilers and Program Optimization
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Browse challenges aligned to your studies.
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Step 03
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