Senior Backend Engineer (Go)

Block Labs; Portugal; On-site; EUR 45,000 - 65,000; Full time

Job summary

Block Labs in Portugal is seeking an experienced backend developer to join their team working on a Cashier-as-a-Service platform for crypto. The ideal candidate will have over 6 years of experience in backend development, expertise in Go, and a solid understanding of distributed systems. Responsibilities include designing backend services, developing core platform features, and collaborating with cross-functional teams to ensure system reliability. Block Labs offers a mature, mission-driven culture focused on clarity and outcomes.

Qualifications

• 6+ years of experience in backend development, ideally in high-throughput or financial systems.
• Strong proficiency in Go as a primary backend language.
• Experience with blockchain integrations, crypto custody, or payment rails is a strong advantage.

Responsibilities

• Design and build distributed backend services for a multi-tenant cashier.
• Develop core platform features for wallet orchestration and payment routing.
• Integrate with blockchain networks and third-party crypto APIs.

Skills

Go programming

Distributed systems

API development (gRPC, RESTful)

Cloud-native environments

Job description

About Block Labs

Block Labs is a premier technology studio operating at the bleeding edge of Web3, Artificial Intelligence, and iGaming. We don't just ship features; we engineer high-scale, production-grade platforms that power the next generation of digital products.

We are a collective of senior engineers, product strategists, and builders who refuse to compromise on architecture. Whether we are designing autonomous multi-agent AI systems, building decentralized financial infrastructure, or architecting high-frequency iGaming platforms, our standard is excellence.

We move fast, but we build for the long term. If you are looking to work alongside a team that values deep technical expertise, thoughtful system design, and product ownership, Block Labs is where you belong.

About The Role

We are developing a multi-tenant Cashier-as-a-Service platform, purpose-built for crypto. This platform provides a unified backend for managing deposits, withdrawals, balances, and settlements across multiple tenants, from exchanges and payment providers to decentralized apps.

You’ll be joining a senior, highly technical team building greenfield backend services at the core of a secure, high-throughput financial platform. We value autonomy, craftsmanship, and long-term thinking, and we’re building systems designed for resilience, transparency, and scale.

Key Responsibilities

• Design and build distributed backend services that power a multi-tenant cashier and transaction management system.
• Develop core platform features for wallet orchestration, payment routing, reconciliation, and tenant onboarding.
• Integrate with blockchain networks, payment gateways, and third-party crypto APIs.
• Collaborate with product, frontend, and infrastructure teams to deliver reliable, end-to-end systems.
• Contribute to architectural design and drive technical decisions across services.
• Ensure scalability, fault-tolerance, and compliance within a regulated financial context.
• Maintain clean, testable, and well-documented Go code following industry best practices.

About You

• 6+ years of experience in backend development, ideally in high-throughput or financial systems.
• Strong proficiency in Go as a primary backend language; experience with gRPC and RESTful APIs is highly valued.
• Solid understanding of distributed systems, multi-tenant architectures, and microservices.
• Experience with blockchain integrations, crypto custody, or payment rails is a strong advantage.
• Comfortable working in cloud-native environments.
• Deep commitment to software reliability, observability, and security best practices.
• Excellent communication skills and a collaborative mindset.

Nice to Have

• Experience with cryptographic key management, wallet abstractions, or transaction signing flows.
• Background in fintech, DeFi, or crypto exchange infrastructure.
• Familiarity with event-driven systems, Kafka, or message queues.
• Prior experience designing APIs for multi-tenant or white-label products.

What kind of culture can I expect?

Mature, mission-driven, and low-ego. We value clarity over noise, outcomes over theatrics, and pace without chaos. If you’re one of the smartest minds in your craft and want to build with other experts, you’ll feel at home here.