Nexus listings engine / Systems
A deliberate path from a market request to live trading.
Rust infrastructure that moves a market from request to listed to active, with readiness checks, durable events, scheduled activation, and a preview before committing.
- My role
- Backend / Systems Engineer
- When
- September 2026 — present
- Built with
- Rust · Distributed systems · Event journals · State machines · API design
Explore how it works
Try it yourself ↓Nexus · listings lifecycle
When is a market ready to open?
Follow a sample listing through the checks that turn a request into a tradable market.
- ProposedA request is recorded
- ListedRegistered, trading closed
- ActiveReady for orders
Saved milestones
01- Listing requested
The same request can be safely retried.
Try listing this sample market while one service is still waiting.
Illustrative model with synthetic data, created for this portfolio. Simplified milestones; no live connection to Nexus.
The challenge
Adding a market touches multiple services. Registration, pricing readiness, and opening trading must happen in a deliberate order while the exchange keeps running. Retries and restarts must preserve the intended operation.
How I built it
Record intent before acting
I built durable listing requests and repeat-safe handling, carrying runtime market configuration through journal replay and snapshots so recovery retains the information needed to continue.
Make readiness explicit
I implemented service readiness checks and reconciliation against observed state. Registration is separate from activation: fresh pricing and the scheduled start must also be ready before trading opens.
Inspect the change before committing
I added a no-write listing preview that shares the command’s validation path, along with lifecycle safeguards for reduce-only execution and delisting readiness.
What came out of it
Merged the backend paths and regression coverage for runtime listing and controlled activation. This is an ongoing body of work spanning requests, recovery, validation, and market lifecycle controls.
The interactive model uses a fictional market and simplified events. It explains the lifecycle without connecting to Nexus or displaying internal data.
Sources & project context
- Authored, merged GitHub pull requests and completed Linear work, reviewed October 2026