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
- CodeBeginnerNew
Design a Race-Free Cache for a Read-Heavy Service
Implement a thread-safe LRU-bounded cache in Java (or Go — your choice, defend it) with: read-write lock or copy-on-write semantics, get-or-load pattern with single-flight to de…
- Concurrent Data Structures
- Race Conditions
- Single Flight
Concurrent and Parallel Programming - CodeIntermediateNew
Build a BM25 + Embeddings Hybrid Search for a Legal-Tech Document Portal
Stand up an OpenSearch cluster with BM25 indexing on the 2.4M-document corpus. Generate dense embeddings (you choose the model; justify cost and quality trade-offs) and index th…
- Information Retrieval
- Bm25
- Vector Database Basics
Data Mining and Information Retrieval - 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 - 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 Develop in-demand professional skills.
Each challenge names the skills it strengthens. Over time, your profile fills with the competences a hiring manager would actually look for.
Why Ewance
- CodeSeniorNew
Implement Distributed Shared Memory Over RDMA for a Trading Firm
Build a DSM library in C++ exposing a region API (allocate, read, write, free). Use ibverbs for RDMA primitives (one-sided read/write, atomics for the directory). Implement dire…
- Distributed Systems Design
- Rdma
- Consistency Models
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 - AnalysisIntermediateNew
Branch Predictor Study for a Cryptocurrency Hashing Library
Profile the hot inner loop with perf record + perf annotate to identify the 5 highest-frequency branches. Measure per-branch mispredict counts using perf counters (BR_MISP_RETIR…
- Branch Prediction
- Performance Counters
- Benchmarking
Computer Architecture - CodeIntermediateNew
Parallelize a CFD Solver with MPI Across 256 Cores
Profile the serial solver to identify the hot loops (likely: pressure-Poisson solve, advection step, BC update). Decompose the domain via 2D block-structured partitioning. Imple…
- Mpi
- Cpp Programming
- Domain Decomposition
High-Performance and Scientific Computing - Browse challenges
Explore role
Strategy Analyst
Frame the business question, model the options, build the recommendation. From market sizing to competitive analysis, this role is where strategy consulting meets in-house decision-making.
- AnalysisBeginnerNew
Instruction Set Analysis for an Embedded Workload
Compile all 12 workload programs to both ISAs using the appropriate cross-compiler (GCC with -march=rv32e for RISC-V; provided proprietary toolchain for the in-house ISA). Repor…
- Instruction Sets
- Code Density
- Embedded Systems
Computer Architecture - AnalysisBeginnerNew
Diagnose a Deadlock in a Multi-Threaded File Indexer
Clone the indexer repo (provided), set up reproduction with thread-sanitizer and helgrind, and produce a deterministic deadlock test case in under 5 minutes of runtime. Diagnose…
- Synchronization
- Deadlock Analysis
- C Programming
Operating Systems - AnalysisBeginnerNew
Audit a Linux Distribution for Setuid Binary Risk
Mount the provided base image (Ubuntu 22.04 LTS derivative) and inventory all setuid + setgid binaries. For each, classify into 4 buckets: legitimately needed, replaceable with …
- Os Security
- Linux Administration
- Setuid Analysis
Operating Systems - CodeSeniorNew
Port a Numerical Kernel from CPU to GPU for a CFD Simulator
Receive the existing CFD solver (C++17 + OpenMP, around 8,000 lines, the hot kernel is a 7-point stencil sweep over a 512^3 grid), the validation harness, and access to an A100 …
- Gpu Programming
- Cuda
- Parallelism
Performance Engineering of Software Systems Get recognized by recruiters and employers.
Credentials are blockchain-anchored via LearnCoin — tamper-evident, portable, link-shareable on LinkedIn and beyond.
Why Ewance
- 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
Implement an LSM-Tree-Based Storage Engine Prototype
Implement the engine in Rust. Components: WAL, memtable (skip list), SSTables on disk with bloom filters and sparse index, two compaction strategies (size-tiered, leveled). Cove…
- Lsm Tree
- Storage Engine
- Systems Language Proficiency (Go, Rust, C++)
Advanced Database Systems - AnalysisBeginnerNew
Cache Configuration Study for a Memory-Bound Workload
Profile the existing inner loop on a workstation with perf to baseline L1/L2/L3 miss rates and miss latencies. Run the same loop through gem5's classic cache model under 6 confi…
- Caches
- Memory Subsystems
- Performance Modeling
Computer Architecture - 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 - CodeSeniorNew
Vectorize a Risk-Calculation Engine for a Mid-Cap Bank
Receive the existing pricer (C++17, scalar, around 600 lines), 2 weeks of representative input data (around 50M paths), the validation harness, and access to an Intel Ice Lake-S…
- Vectorization
- Avx 512
- Simd
Performance Engineering of Software Systems - 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
- Postgresql Or Mysql
- Postgresql Or Mysql
Introduction to Database Systems - CodeSeniorNew
Implement Raft Consensus for a Self-Hosted Feature-Flag Service
Implement the core Raft algorithm (leader election, log replication, snapshotting) from the original Ongaro & Ousterhout paper. Use an embedded key-value store (BoltDB or sled) …
- Raft Consensus
- Go Programming
- Grpc
Distributed Systems - 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…
- Apache Spark
- Finops & Cost Optimization
- Etl Pipelines
Big Data and Data-Intensive Systems - 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 - CodeBeginnerNew
Build a Multi-Level Feedback Queue Scheduler in xv6
Fork the xv6-riscv repository and implement MLFQ in proc.c with 3 priority queues, per-queue time slices (10ms / 20ms / 40ms), priority demotion on slice exhaustion, and a 100ms…
- Operating Systems
- Scheduling
- C Programming
Operating 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 - 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
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.
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