Smilee Finance
Building an options trading app, from interface to protocol data
- Role: Software Engineering
- Company: Smilee Finance
Overview
Building Smilee’s first product: options trading on Arbitrum.
From October 2023 through July 2024, I worked on Smilee’s first product, an options protocol on Arbitrum. It is no longer live. My main focus was frontend development: implementing the trading interface pixel-perfectly from the team’s Figma designs.
I also implemented the subgraph that indexed product data and worked on the Smilee SDK used across the app, internal dashboard and side projects. Those three layers—UI, indexed data and shared integrations—were closely connected in day-to-day product work.
Selected outcomes
- The protocol handled $2m in TVL.
- Reduced RPC calls by 60%.
- Reduced data and page load times by 70%.
01 / Options UI
Pixel-perfect, all the way to production
I translated Figma designs into the production trading interface, with close attention to layout, typography, spacing and component states. Precision mattered: this was a financial product where users needed to read positions, prices and actions clearly.
The implementation also had to hold up beyond the ideal design state, as wallet connection, live data and transactions changed what appeared on screen. I worked with the design team to turn the visual system into a functioning product.
02 / Subgraph
Making onchain activity usable as product data
At the time, the subgraph was Smilee’s only backend service for data indexing. I implemented the layer that turned protocol activity into queryable data for the app:
- User positions
- Transaction history
- Vault TVL
- Prices
It gave the interface a way to show a user’s activity and the state of the vaults without asking the browser to reconstruct that history directly from chain events.
03 / Smilee SDK
One integration layer for every client
I worked on the Smilee SDK, the shared integration layer used by the trading app, internal dashboard and side projects. It brought together:
- Chain interaction
- Wallet connection
- API and GraphQL calls
- Token prices
Keeping these capabilities in one SDK let each client build on the same protocol interface instead of reimplementing its own path to contracts and product data.
