Arenema is hiring a Crypto / Blockchain Developer to join a fast-moving fintech engineering team building a custodial digital-asset platform — on/off-ramp, cross-chain swaps, streaming payments and stablecoin operations across multiple EVM networks.
This is a hands-on, backend-leaning role for an engineer who is genuinely comfortable at the intersection of EVM smart contracts, custodial wallet infrastructure, and production fintech backend services. You'll own real features handling real funds — not testnet side projects.
What you'll work on
- Custodial wallet management — build and maintain the wallet layer that creates and manages Gnosis Safe wallets (Safe Singleton / Proxy Factory) for customers and treasury across EVM networks, including wallet validation across payments, transfers, streams and swaps.
- Multi-approval / multi-sig governance — evolve transaction approval flows from single-key custody toward on-chain multi-approval (Safe governance modules / native threshold), covering propose approve execute.
- Stablecoin & token operations — implement and maintain logic for EUR-denominated / e-money stablecoins and ERC-20 tokens, including balances, transfers and dashboard valuation.
- Streaming / streamable payments — develop and maintain programmable payment-streaming features (start, stop and reconcile live streams).
- Cross-chain swaps — own and extend a cross-chain swap aggregator integration (asset lists, swap service, trade history).
- Smart-contract integration — work with deployed Solidity contracts (Safe core + custom governance/fee modules), maintain backend Web3 encoders, and coordinate contract deployment across networks (Polygon, BNB Chain, Gnosis Chain).
- On-chain fees & treasury — build and maintain fee-collector and treasury logic.
- Production hardening — deployment procedures, monitoring, kill-switch and reliability of event-driven microservices.
What we're looking for
- 3+ years software development, with 2+ years hands-on blockchain / Web3 in production.
- Strong Java / Spring Boot backend engineering (or equivalent strong JVM backend experience).
- Solid EVM & Solidity smart-contract development and integration.
- Working knowledge of Gnosis Safe (Singleton, Proxy Factory, modules, owners/threshold, execTransaction).
- Strong AI Assisted development experience.
- Backend Web3 integration (Web3j or equivalent) — transaction encoding, signing, nonce handling, EIP-712.
- Experience with custodial wallet infrastructure and KMS/HSM-based signing (e.g. AWS KMS).
- Experience integrating DEX / cross-chain swap aggregators (e.g. Rubic, LI.FI, 0x, 1inch, Socket).
- Familiarity with stablecoins / e-money tokens (ERC-20 mechanics).
- Comfortable across multiple EVM networks and deploying contracts to each.
- REST APIs, SQL databases, and event-driven / message-queue architecture (RabbitMQ or similar).
- AWS familiarity and CI/CD / GitOps practices.
- A strong security mindset — backend-enforced vs. on-chain-enforced guarantees, audit trails, single-key custody risks.
Nice to have
- Streaming / programmable payments experience (Superfluid, Sablier, LlamaPay or custom).
- Multi-sig governance and on-chain approval workflow design.
- Tokenised real-world assets (RWA) or DeFi (staking, lending) exposure.
- Fintech / payments compliance in a regulated environment (KYC, transaction monitoring, operational resilience).
- Experience supporting a back-office / operations console for a financial platform.
Profile
- Senior-leaning mid-level engineer who takes ownership of crypto/wallet features end-to-end with limited supervision.
- Has shipped production blockchain systems handling real funds.
- Comfortable in an agile / Scrum delivery model (JIRA, Confluence) with code review, QA hand-off and clear documentation.
- Fluent English (written and spoken) for collaboration with a Europe-based team.
Why join
- Core role on a platform heading to commercial launch — real ownership of the crypto/wallet domain.
- Modern EVM, Safe and DeFi stack with room to shape architecture (multi-sig migration, new asset classes, DeFi exploration).
- Remote-first from India within a collaborative, cross-functional European team.
