Migrate a 6TB Social-Commerce Database to a Sharded Topology
Overview
What this challenge is about.
Migrate a 6TB Social-Commerce Database to a Sharded Topology. Advanced challenge in design. Designing real products under real constraints, earn a blockchain...
The Brief
What you'll do, and what you'll demonstrate.
Design and prototype a 16-shard PostgreSQL topology with a routing layer and a six-month dual-write migration path that requires no maintenance windows.
This is not a design exercise. It is the work a product designer does between a brief and a shipped interface. That distinction matters to every hiring manager who has seen candidates redesign Spotify's homepage and none who have worked under real product constraints.
When you finish, you will have something most graduates do not: a real-world deliverable, verified by Ewance, that you can show to a hiring manager and say "I did this. Here is the proof."
Earning criteria — what you'll demonstrate
- Derive shard-key decisions from measured query workload instead of assumed access patterns.
- Identify tables unsuited to a user-based shard key and choose between global replication and a separate unsharded service.
- Implement a routing layer that correctly handles cross-shard fan-out, result merging, and shard failover.
- Plan a zero-downtime migration using dual-writes and read-shadowing with per-phase rollback safety.
- Size a sharded topology against real capacity metrics and defend the headroom.
Program Fit
Where this fits in your program.
Sharpens the same skills your degree expects you to demonstrate.
Aligned coursework coming soon.
Skills
Skills you'll demonstrate.
Each one shows up on your verified credential.
- Database Sharding
Apply database sharding to solve real industry problems and demonstrate production-level capability.
- Postgresql
Apply postgresql to solve real industry problems and demonstrate production-level capability.
- Vitess
Apply vitess to solve real industry problems and demonstrate production-level capability.
- Dual Write Migration
Apply dual write migration to solve real industry problems and demonstrate production-level capability.
- Capacity Planning
Apply capacity planning to solve real industry problems and demonstrate production-level capability.
- Schema Design
Apply schema design to solve real industry problems and demonstrate production-level capability.
Careers
Career paths this challenge builds toward
Completing this challenge demonstrates skills that transfer directly to these roles:
Senior Database Administrator
Running a real sharding migration on evidence rather than assumption mirrors the senior DBA's core job: defending topology decisions to engineering leadership and owning a zero-downtime cutover end to end.
This challenge sharpens
- database-sharding
- postgresql
- dual-write-migration
Database Reliability Engineer
Designing per-phase rollback gates and read-shadow verification under a live write ceiling is exactly the reliability-engineering remit of keeping a high-traffic datastore available while it changes shape underneath production.
This challenge sharpens
- capacity-planning
- dual-write-migration
- postgresql
Data Platform Engineer
Building a routing layer that abstracts shard topology from application code is the foundational platform-engineering skill of giving product teams a stable data interface over a distributed backend.
This challenge sharpens
- vitess
- schema-design
- database-sharding