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Feels Protocol

Solana DEX Trading Platform

Overview

Role: Main developer — owned the platform end-to-end: the Next.js trading UI, the Rust indexer/backend, the on-chain integration, and CI/CD.

feels-indexer in Rust on Tokio over a four-backend storage layer — PostgreSQL for analytics, RocksDB for raw account state, Redis for hot cache, and Tantivy for token search. Discriminator-routed Borsh deserialization across 10+ Solana account types and on-chain event types, exposed via ~40 REST endpoints with Scalar OpenAPI docs and Prometheus metrics.

Key Features

  • Rust indexer on Tokio over a four-backend storage layer (PostgreSQL, RocksDB, Redis, Tantivy)
  • Discriminator-routed Borsh deserialization across 10+ Solana account and event types
  • ~40 REST endpoints with Scalar OpenAPI docs and Prometheus metrics
  • Mock Geyser (localnet/CI) and Yellowstone gRPC (devnet/mainnet) streaming via Cargo feature flag
  • Redis pub/sub for hot-path cache invalidation
  • Tantivy full-text search for token discovery

Tech Stack

Indexer

RustTokioAxumBorshsqlx

Storage & Search

PostgreSQLRocksDBRedisTantivy

Solana & Web3

Solana wallet adaptersYellowstone gRPCMetaplexWASM

Testing & Observability

PlaywrightLiteSVMScalar OpenAPIPrometheus

Frontend

Next.js 16React 19TypeScriptTailwind CSSBun

Challenges & Solutions

Indexing High-Volume On-Chain State

Problem

Deserializing and serving 10+ Solana account types and on-chain events at trading-app latency needs more than a single database can offer.

Solution

Built a Rust indexer on Tokio over a four-backend storage layer — PostgreSQL for analytics, RocksDB for raw account state, Redis for hot cache, and Tantivy for token search — with discriminator-routed Borsh deserialization and a Cargo feature flag switching between mock Geyser and Yellowstone gRPC streaming.

Slow, Flaky Full-Stack Tests

Problem

On-chain integration tests against a live validator were slow and non-deterministic, and env drift between frontend, RPC, indexer, and on-chain program made failures hard to trust.

Solution

Built a two-lane Playwright setup — a deterministic test-wallet lane and a LiteSVM in-memory RPC lane — and added a deployment-coherence pre-check asserting frontend env, RPC, indexer URL, program ID, and token mints all match before any product assertion runs.

Untrusted Browser-to-Indexer Access

Problem

A trading SPA talking directly to the indexer from the browser opens cross-origin fetch and token-leak risks, and the boundary erodes the moment any component reaches for a raw fetch.

Solution

Routed all browser-to-indexer traffic through a single API proxy as the only ingress, and enforced it with a custom ESLint rule that bans raw cross-origin fetch in the app, removing whole classes of CSRF and token-leak bugs.

Key Achievements

4 Backends
PostgreSQL + RocksDB + Redis + Tantivy
10+ Types
Borsh deserialization across Solana accounts + events
~40 Endpoints
REST surface with Scalar OpenAPI + Prometheus
2 Modes
Mock Geyser ↔ Yellowstone gRPC via Cargo feature flag