Computer & Information Sciences
Information Systems Challenges
Real information-systems challenges on Ewance — model data, integrate systems, and align technology with how an organisation actually runs. Solve them to build a portfolio of verified, recruiter-checkable proof you can do the work — not just describe it.
Recommended challenges
- 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…
- Spark
- Cost Optimization
- Etl Pipelines
Big Data and Data-Intensive Systems - AnalysisSeniorNew
Diagnose Clock Skew in a HFT Order Matching System
Receive anonymized PTP grandmaster + slave logs (nanosecond resolution, 30 days, 3 cabinets) plus a synthetic order-flow generator. Identify the drift pattern (likely candidate:…
- Logical Clocks
- Ptp Time Sync
- Cpp Programming
Distributed Systems - AnalysisIntermediateNew
Cache Coherence Protocol Comparison on a Multicore Simulator
Stand up gem5's Ruby coherence framework with both MESI and MOESI protocols on a 16-core configuration. Run the 6-benchmark suite (provided): producer-consumer queue, false-shar…
- Cache Coherence
- Multicore Architecture
- Simulation
Advanced Computer Architecture - 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
Operating Systems 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
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
- Go
Concurrent and Parallel Programming - 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 - ResearchSeniorNew
Compare NewSQL Architectures for a Real-Time Inventory Platform
Study the architecture papers and documentation for CockroachDB (its Spanner-inspired multi-active design), TiDB (Raft + multi-Raft + TiKV + TiDB SQL layer), and Spanner (TrueTi…
- Newsql
- Distributed Databases
- Raft
Advanced Database Systems - DesignSeniorNew
Design a Strong-Consistency Distributed Counter Service
Design the service end-to-end: storage (Spanner / CockroachDB / FoundationDB — you choose), counter scheme (sharded counters with periodic reconciliation vs strongly-consistent …
- Distributed Databases
- Consensus
- Strong Consistency
Advanced Database Systems - Browse challenges
Explore role
Marketing Analyst
Plan and measure campaigns that grow the business. Funnel analytics, attribution, segmentation, and the rigorous measurement that lets marketing defend its budget at the leadership table.
- AnalysisBeginnerNew
Pick a NoSQL Store for an Event-Stream Sidecar Cache
Set up identical 3-node clusters of Redis 7, KeyDB, and DragonflyDB on equivalent hardware. Run the team's captured 24-hour workload trace (around 180k ops/second, 80/20 read/wr…
- Nosql
- Redis
- Benchmarking
Introduction to Database Systems - AnalysisIntermediateNew
Design a Custom Page-Replacement Policy for a Tier-1 Cloud Provider Simulator
Use the provided simulator (Python harness wrapping a C++ page-cache model) and the team's 3 anonymized workload traces (web-cache, key-value store, batch analytics). Implement …
- Memory Management
- Page Replacement
- Benchmarking
Operating Systems - CodeSeniorNew
Port a CPU Monte-Carlo Simulator to GPU for an Energy Trader
Receive the existing simulator (C++17 + OpenMP, around 5,000 lines), the test book (around 8,000 spread options), and access to an H100 80GB. Port to CUDA: random-number generat…
- Gpu Programming
- Cuda
- Monte Carlo
Advanced Concurrency and Parallel Computing - StrategyBeginnerNew
Migrate a Local-Government Records System from MySQL to PostgreSQL
Audit the MySQL schema (around 60 tables) for incompatibilities (case-folding identifiers, ENUM types, TIMESTAMP semantics, character sets). Plan a migration using pgloader for …
- Database Migration
- Mysql
- Postgresql
Introduction to Database Systems 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
- CodeSeniorNew
Profile and Tame a P99-Latency Tail for an Ad-Auction Service
Receive the bidder source (Go, around 22,000 lines), production traces (eBPF + flame graphs from 30 minutes of peak traffic), and the host config (NUMA-2 socket, 96 cores, 384GB…
- Performance Optimization
- Ebpf
- Go
Performance Engineering of Software Systems - AnalysisSeniorNew
Diagnose and Fix Query-Planner Misestimates in a FinTech Warehouse
For each of the 6 queries, capture EXPLAIN (ANALYZE, BUFFERS) and compare estimated vs actual rows at each node. Identify the misestimate source per query (single-column stats s…
- Query Optimization
- Postgresql Planner
- Extended Statistics
Advanced Database Systems - ResearchBeginnerNew
Survey Information-Retrieval Research for an AdTech Platform's Roadmap
Build a reading list of 30-40 papers spanning SIGIR, RecSys, KDD, WSDM, and arXiv from 2023-2025 across (a) dense retrieval architectures, (b) learning-to-rank with click feedba…
- Information Retrieval
- Learning To Rank
- Research Synthesis
Data Mining and Information Retrieval - CodeSeniorNew
Port a Microkernel IPC Mechanism to a New Architecture
Fork the project repository and port the synchronous IPC fast path to RISC-V (RV64GC). Preserve the existing fast-path invariants: register-only message passing for messages und…
- Microkernels
- Ipc
- Risc V
Advanced Operating Systems - DesignIntermediateNew
Design a Geo-Distributed Storage Layer for an EdTech
Map the access patterns (90 percent reads from the country of origin, 10 percent cross-country via teacher reviewers). Design region routing using a metadata service backed by a…
- Geo Distribution
- Data Residency
- Cockroachdb
Distributed Systems - CodeIntermediateNew
Apply Software Transactional Memory to a Real-Time Auction Book
Implement two variants of the same auction-book API (best-bid/best-ask lookup, place-order, cancel-order, match-orders): (1) baseline with java.util.concurrent locks + a SkipLis…
- Transactional Memory
- Concurrent Data Structures
- Haskell
Advanced Concurrency and Parallel Computing - AnalysisIntermediateNew
GPU Roofline Model Study for a Computer Vision Inference Workload
Construct empirical roofline plots for the current GPU (A100-class) and next-gen GPU (H100-class) using vendor-published peak FLOPs and measured peak memory bandwidth. Profile t…
- Gpu Architecture
- Roofline Model
- Performance Modeling
Advanced Computer Architecture - AnalysisSeniorNew
Memory Consistency Model Audit of a Lock-Free Queue
Read the SPSC queue source (around 200 lines of C++). For each atomic operation, classify the required ordering and verify the chosen memory_order is sufficient under both x86-T…
- Memory Consistency
- Concurrency
- Lock Free Programming
Advanced Computer Architecture - AnalysisIntermediateNew
Tune Consistency Levels for a Global Ride-Hailing Platform
Receive an anonymized topology export (3 regions, RF=3 per region) plus 7 days of query traces tagged by class. Reproduce the matching anomaly in a Kubernetes-based test cluster…
- Consistency Models
- Cassandra
- Distributed Tracing
Distributed Systems - DesignIntermediateNew
Migrate a Monolithic Database to a Sharded Topology
Analyze schema (32 tables) + query workload (anonymized 7-day pg_stat_statements export) to identify the right shard key per table. Most tables shard on user_id; identify the 4-…
- Database Sharding
- Postgresql
- Vitess
Distributed Systems
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
Hiring from this pool?
Sponsor a challenge and meet candidates through actual work.
Industry teams can shape briefs around the skills they hire for, then evaluate students on rubric-scored deliverables — not resumes.