Blockchain Backend Developer
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- Blockchain Backend Developer
- Limassol
- Development
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Requirements
- 3+ years of backend development experience and 2+ years in crypto/blockchain projects with production-level workloads;
- Strong experience building services in TypeScript (NestJS) and/or Go;
- Deep understanding of Ethereum, TRON, BNB, BTC-like chains, TON, and their RPC/API mechanisms;
- Web3: experience working with web3.js, ethers.js, or similar libraries for network interaction and transaction signing;
- Experience integrating with nodes via RPC/REST/gRPC, including error handling and managing multiple clients;
- Hands-on experience designing and maintaining block indexers and transaction-processing services;
- Strong SQL skills, including query optimization, schema design, and zero-downtime migrations;
- Experience writing unit, integration, and end-to-end tests for critical financial scenarios;
- Understanding of financial risks, secure handling of private keys, and protection against attacks;
- Experience with Prometheus and Grafana for metrics, monitoring, and alerting;
- Participation in code reviews, ability to write clean, readable code, and document technical decisions.
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Key responsibilities
- Deposits: development and maintenance of block indexers (EVM, BTC-like, Tron, TON, Solana), log and UTXO processing, detection of incoming transactions and confirmations, handling reorg scenarios, ensuring idempotency and correct event delivery to Payments/Wallet systems;
- Withdrawals: preparation, signing, and broadcasting of transactions (EVM/BTC-like/Tron/TON), lifecycle management of transaction statuses, implementation of limits logic, safe balance checks, automatic token sweeping, retries, and atomic status persistence in the database;
- Node interaction: integration with RPC/REST/gRPC, query optimization, node health monitoring, network error handling, and support for multiple client versions through a unified abstraction layer;
- Architecture: participation in designing scalable and fault-tolerant solutions for indexers, broadcasters, workers, and schedulers, implementing best practices for reliability and fault tolerance;
- Integrations: collaboration with Payments, Wallet, and AML domains to build end-to-end payment flows, configure event streams, and ensure correct processing of business states;
- Databases: PostgreSQL schema design, query optimization for indexers/workers, implementation of zero-downtime migrations, use of distributed locks and idempotent operations;
- Testing: development of unit, integration, and end-to-end tests; checking edge cases (reorgs, stuck transactions, double spend); ensuring stable and predictable releases;
- Observability: implementing metrics and logging for indexers and broadcasters, setting up monitoring and alerting (Prometheus/Grafana), incident analysis, and improving service resilience;
- Security: handling private keys, Vault/KMS/HSM, protection against replay attacks, access control, operation auditing, and financial risk management;
- Code quality: participation in code reviews, refactoring, documenting technical decisions, following internal engineering standards, and maintaining a clean, modular codebase.
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Desirable
- Fintech: experience working with payment or crypto-financial products;
- Smart Contracts: basic skills in developing or reading smart contracts in Solidity or Rust;
- Event-driven: experience designing microservice and event-driven systems using Kafka or RabbitMQ;
- Integrations: experience working with external APIs, payment providers, and complex business flows;
- CI/CD: knowledge of best practices for delivery, testing, and operation of blockchain services;
- SDK: experience creating custom SDKs, CLIs, or libraries for blockchain interaction;
- Open-source: contribution to open-source projects or having your own technical pet projects.
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What we offer
- High salary (plus performance bonuses and salary revision on a regular basis);
- Work schedule: Mon-Fri (9h with 1h lunch break), flexible start 8:00-10:00;
- 24-days holiday leave;
- First line seaview from your office;
- Corporate English lessons;
- GYM and SPA in the office;
- Corporate meals;
- Eventful corporate life;
- Exciting work challenges that allow you to grow to your full potential;
- Strong team of like minded professionals who will be by your side to accomplish ambitious projects, and to stimulate your professional development and bring experience.
International IT
Inktech is an international product software company driving innovation in iGaming, FinTech, and Payments.
Our mission is to deliver cutting-edge software solutions along with comprehensive services in marketing, traffic, and payments for the global market.
Since 2017, we have been growing rapidly, bringing together top talent to achieve outstanding results.
At Inktech, your skills are not only recognised — they're rewarded. Join us to take your career and earnings to the next level.
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Inktech benefits
On the market, we have grown into a profitable and rapidly expanding company with 800+ professionals worldwide
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High salary
We provide a salary that surpasses industry averages to recognise and reward our employees' expertise.
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Company lunches & snacks
We provide a selection of snacks and lunches to ensure access to healthy and convenient meals.
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Wellbeing
We provide access to a gym and offer reimbursement for massage therapy.
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Corporate events
Regular team-building activities such as yacht races, karting, and hiking, often with family members invited to join.
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Mobile communication
Employees receive a corporate SIM card with unlimited calls and mobile data from a local provider.
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Employee assistance desk
At Inktech, we value your focus. Our Office Manager team, available in the office, is here to help with everyday tasks — from finding a reliable kindergarten for your child to sourcing the right food for your allergic cat.
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English classes
Free English tuition is available for all employees, with classes tailored to different proficiency levels.
relocation support