Take on real engineering builds posted by companies. Your solutions become a verified profile that hiring teams actually search.
Start your first buildFree to start. No credit card.
You built a to-do app and a weather dashboard. So did 50,000 other students. Nobody's reviewing your GitHub. Nobody knows if you actually wrote it.
You completed 14 certification courses and have DSA badges. So does everyone who paid ₹399 and followed along. It proves you can follow instructions, not that you can engineer.
You submitted your resume to 30 companies through your college. HR screened it for 7 seconds, couldn't tell you apart from 200 others, and you never heard back.
The problem isn't your skill. It's that nothing you're doing right now actually proves it.
Three steps. No resumes. No algorithm quizzes.
Step 01
Browse open builds posted by real companies. Each one is a real engineering problem — not a DSA puzzle or a tutorial project.
Step 02
Work in your own IDE. When you’re done, submit your GitHub repo. That’s the entire submission process.
Step 03
Your submission is processed by XVal, XcelCrowd’s evaluation system, across 7 engineering dimensions. You get a detailed review with scores, feedback, and where you stand, regardless of your rank.
Every submission gets this — whether you score 92 or 43. Pass or not, you walk away knowing exactly where you stand and what to work on.
Stealth Fintech Startup
6 of 8 tests passed. 2 failures in batch processing suite.
Review Summary
Your code cleanly separates the reconciliation logic from the payment provider connections — that's a strong design choice. One thing to improve: when errors happen during payment processing, you're handling recovery in three separate places. Try creating a shared error handler that all three can use. This is called 'extracting middleware' — it makes debugging much easier when something breaks in production.
Strengths
Areas for Improvement
Key Issues
src/adapters/StripeAdapter.ts:61, PayPalAdapter.ts:44, SquareAdapter.ts:52
→ Extract into shared withRetry() middleware with configurable exponential backoff and jitter.
At production payment companies, retry middleware is shared infrastructure. Duplicated retry logic drifts silently when one handler is updated.
tests/adapters/
→ Add integration tests simulating partial gateway failures mid-batch. Verify completed transactions survive.
Payment systems require exhaustive failure-mode testing. Partial batch failures are the production norm.
src/handlers/BatchProcessor.ts:12–14
→ Accept adapters via constructor injection for testability and zero-downtime provider rotation.
Dependency injection is how production payment systems add new gateways without modifying handler code.
src/services/ReconciliationEngine.ts, src/adapters/StripeAdapter.ts, PayPalAdapter.ts, SquareAdapter.ts
src/services/DiscrepancyDetector.ts — event-driven flagging within reconciliation loop
Typed errors in src/errors/ but bare catch blocks in src/handlers/BatchProcessor.ts:92
src/handlers/BatchProcessor.ts — batching works but retry strategy inconsistent across adapters
No OpenAPI spec found — README.md covers features only
Code Files
18
Avg Lines/File
94
Max File Lines
312
Concentration
14%
Folder Depth
4
Comment Ratio
0.06
This is how engineers improve on XcelCrowd.
| Build | Score | Rank | Readability | Error Handling | Architecture |
|---|---|---|---|---|---|
| Build 1 | 48 | Top 61% | fair | poor | fair |
| Build 2 | 57 | Top 38% | good | fair | fair |
| Build 3 | 71 | Top 19% | good | good | good |
| Build 4 | 81 | Top 9% | excellent | good | excellent |
Each one showed exactly what to fix. No course. No bootcamp. Just real problems and real feedback.
Real engineering problems from real companies. Pick one and start building.
Stealth Series A Fintech
Design a service that reconciles payment records across multiple gateway providers and flags discrepancies in real time.
Stealth B2B SaaS Startup
Build a notification system that supports email, SMS, and in-app channels with per-tenant rate limiting and delivery tracking.
Stealth D2C Platform
Create an API that calculates optimal delivery routes given a set of waypoints, time windows, and vehicle constraints.
Every build you complete adds to a profile that companies actually search. Not a resume. Not a certificate. Proof.
Based on 7 completed builds
Payment Reconciliation Service
Stealth Fintech Startup
Top 18%
Multi-Tenant Notification Engine
Series A SaaS Company
Top 9%
Route Optimization API
B2B Logistics Platform
Top 32%
Real-Time Chat Backend
EdTech Scale-Up
Top 12%
Inventory Sync Pipeline
D2C E-Commerce Startup
Top 22%
Your profile is searchable by stack, scores, and build history. When a hiring team needs someone who builds well in your stack, your profile shows up. You don't apply. They find you.
Post a real engineering problem. Receive ranked candidates with full evaluation reports and GitHub proof.
Talk to us →