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Software Engineering

Backend Engineer

If you like the kind of work a Backend Engineer does, every challenge here gives you a chance to do that work on a real industry brief.

Skills you'll need

Showing Backend Engineer challenges in Code. Clear filter

Recommended Challenges

· Intermediate only Clear

CodeIntermediateNew
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
CodeIntermediateNew
Knowledge-Graph Recommender for a Niche Online Bookstore
Model the catalog as a knowledge graph (nodes: books, authors, genres, themes, eras, awards; edges: wrote, in-genre, has-theme, won, similar-to). Use Neo4j or a simple Python in…
- Knowledge Representation
- Knowledge Graphs
- Python Programming
Introduction to Artificial Intelligence (CS Elective)
CodeIntermediateNew
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 an Embedding-Based Semantic Search for a Legal-Document Corpus
Embed the 380k-document corpus using a multilingual sentence-transformer (e.g. multilingual MPNet or LaBSE). Store embeddings in FAISS or pgvector. Build a search service that r…
- Deep Learning
- Ml Applications
- Python Programming
Machine Learning (CS Elective)
Practice your coursework on real scenarios.
Every challenge is shaped from real industry context — not generic exercises. The work mirrors what your degree prepares you for.
Why Ewance
CodeIntermediateNew
Build a Reliable Transport Layer Over UDP
Implement in Go: connection establishment (3-way handshake), sequenced and acknowledged data segments, retransmission timer with exponential backoff, fast retransmit on triple d…
- Tcp Ip
- Reliable Transport
- Udp
Computer Networks
CodeIntermediateNew
Churn-Prediction Model for a B2B Vertical SaaS
Use 18 months of anonymized data (provided) covering: usage events, login frequency, support tickets, NPS responses, billing health, feature adoption, practice firmographics. De…
- Supervised Learning
- Python Programming
- Ml Applications
Machine Learning (CS Elective)
CodeIntermediateNew
Diagnose and Fix a Deadlock in a Multi-Threaded Payments Service
Receive the service source (Java 21 + Spring Boot, around 30,000 lines), 4 thread dumps from production deadlocks, and a load harness that reproduces the bug roughly 1 in 50 run…
- Deadlock Analysis
- Locks And Monitors
- Java
Concurrent and Parallel Programming
CodeIntermediateNew
Refactor a Node.js Service into Scala with Effect Systems
Take the existing Node.js price-normalization code (provided). Rewrite in Scala 3 using ZIO (or Cats Effect) — model every effect explicitly (IO for side effects, Either or type…
- Scala Programming
- Zio Effects
- Cats Effect
Functional Programming
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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.
Browse challenges
CodeIntermediateNew
Structured Logging Migration for a Healthcare SaaS Monolith
Receive the current Lograge-flavored Rails logger and 3 sample log files (anonymized PHI). Design: a structured-log JSON schema (request_id, user_id, route, status, duration_ms,…
- Structured Logging
- Loki
- Phi Redaction
Software Observability
CodeIntermediateNew
Implement Authentication and Access Control for a Civic Portal
Receive the current Next.js + Express prototype, the data model (residents, requests, documents, audit log), and the 4 staff roles (resident, clerk, supervisor, auditor) with th…
- Authentication
- Authorization
- Rbac
Introduction to Computer Security

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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Skills and disciplines shown on this page are derived from the Ewance challenge catalogue. When the median annual salary is available for this role via Adzuna, it will be shown above with the sample size and country.