Arnau Espin
Software & product engineer · Andorra, Europe (CET/CEST)
I build full-stack applications and backend systems with TypeScript, React/Next.js, and Rust, turning complex workflows into software that's straightforward to use. My work spans billing, manufacturing, and Solana liquidity management, from interfaces and APIs to indexing and integrations.
Experience
- Aug 2024–present
Software EngineerUNCX
Built the Next.js/tRPC frontend for reviewing positions and managing locked liquidity. Users previously entered pool addresses manually; I added wallet-position discovery on page load, cached with Redis, and removed unused setup steps. The result was less manual entry and a simpler liquidity-locking workflow.
Developed the web integration for Meteora DLMM liquidity lockers; contributed to Raydium and PumpSwap integrations. Built Rust/Carbon event indexers to supply position data, fixed Next.js/tRPC serialization with custom SuperJSON decoders, and contributed transaction retry handling, TypeScript SDK components, and execution tests.
- Jan 2025–May 2026
Full-Stack DeveloperSoftware Agency
Accounting client · Concurrent role
Delivered an engagement game and a reusable AI-prompt dashboard for an accounting community. Worked directly with the client on requirements and pain points, proposed tailored workflows, broke delivery into Jira stories, and demonstrated working features for acceptance.
Built React/Next.js interfaces and backend workflows with PostgreSQL data models and Clerk authentication. Members could create, organize, browse, copy, and edit saved prompts for recurring tasks.
- Feb 2023–Oct 2024
Software EngineerOmnia Protocol
Built billing services and TypeScript/Rust REST APIs with PostgreSQL and Redis job queues. Added service-health and blockchain-event monitoring with Prometheus, Grafana, and Slack/email alerts to surface service issues.
Managed Dockerized services, CI/CD pipelines, and cloud production deployments alongside backend implementation.
- Apr 2022–Feb 2023
Software EngineerBoxfish Studio
Led development of the Synergy Land player dashboard for NFT staking, quests, season passes, and reward eligibility. Built Fontana, a Solana token faucet with server-side signing to keep signing credentials out of the client.
Used TypeScript, Next.js, and Solana Web3.js; automated NFT snapshots, wallet allowlists, and reward allocations to prepare player distributions.
- Oct 2020–Apr 2022
Systems EngineerAG Solution
Developed AngularJS manufacturing execution system modules and .NET/SQL Server integrations connecting production tracking with backend records.
Performed pre-release QA on workflows and integrations, and wrote technical documentation for maintenance and cross-team handovers.
Open Source Contributions
Surfpool · Solana Foundation
Added a stop command for local development environments. Fixed Linux daemon startup by replacing the fork dependency with a direct libc call and reporting startup errors.
txtx · Solana Foundation
Added token-creation and account-data patching actions for development workflows, plus Token-2022 transfer support and unit tests. Removed unused RPC-auth inputs from five Solana actions and updated their documentation.
Superbank · Solana RPC
Contributed local-development provisioning and two Rust/RocksDB changes that replace per-record reads with batched transaction-position and signature-status lookups.
Projects
OpenOCR
A Rust desktop tool that makes non-selectable screen text reusable through a local vision model, without cloud inference. Select a region across connected monitors, preview the capture and extracted text, then copy it to the clipboard.
Fragmentor
An Anchor program and Next.js interface for splitting, distributing, and recombining NFTs on Solana.
Git Horse
A personal project: a cross-platform graphical Git client built with Tauri, Rust, TypeScript, and Vue.
Awards
Euler Labs' EulerSwap Advanced Builds first prize at ETHGlobal Cannes 2025. Built analytics and position-management tools for the project.