Crypto & Web3 Jobs in Sofia, Bulgaria

Join Tether and Shape the Future of Digital Finance At Tether, we’re not just building products, we’re pioneering a global financial revolution. Our cutting-edge solutions empower businesses—from exchanges and wallets to payment processors and ATMs—to seamlessly integrate reserve-backed tokens across blockchains. By harnessing the power of blockchain technology, Tether enables you to store, send, and receive digital tokens instantly, securely, and globally, all at a fraction of the cost. Transparency is the bedrock of everything we do, ensuring trust in every transaction.Innovate with Tether Tether Finance: Our innovative product suite features the world’s most trusted stablecoin, USDT, relied upon by hundreds of millions worldwide, alongside pioneering digital asset tokenization services. But that’s just the beginning: Tether Power: Driving sustainable growth, our energy solutions optimize excess power for Bitcoin mining using eco-friendly practices in state-of-the-art, geo-diverse facilities. Tether Data: Fueling breakthroughs in AI and peer-to-peer technology, we reduce infrastructure costs and enhance global communications with cutting-edge solutions like KEET, our flagship app that redefines secure and private data sharing. Tether Education: Democratizing access to top-tier digital learning, we empower individuals to thrive in the digital and gig economies, driving global growth and opportunity. Tether Evolution: At the intersection of technology and human potential, we are pushing the boundaries of what is possible, crafting a future where innovation and human capabilities merge in powerful, unprecedented ways.Why Join Us? Our team is a global talent powerhouse, working remotely from every corner of the world. If you’re passionate about making a mark in the fintech space, this is your opportunity to collaborate with some of the brightest minds, pushing boundaries and setting new standards. We’ve grown fast, stayed lean, and secured our place as a leader in the industry. If you have excellent English communication skills and are ready to contribute to the most innovative platform on the planet, Tether is the place for you. Are you ready to be part of the future? About the job Cosmic AC is Tether Data's GPU compute and managed inference platform: GPU containers, managed inference endpoints and platform observability, delivered as a self-hosted package on Kubernetes, with a control plane written in JavaScript. The platform is expanding from orchestrating workloads on a managed cluster to owning the full stack on bare-metal GPU infrastructure: a managed Slurm scheduling layer for internal research and model-training teams first, and our own Kubernetes control plane for inference tenancy after that.The Technical Lead owns the architecture and delivery of that stack and leads the engineering team building it: about twelve engineers across backend, frontend, DevOps, QA and documentation, distributed across Europe and India. The role reports to the Senior Technical Product Manager for Cosmic AC, who owns scope, sequencing and partner commitments; the Technical Lead owns architecture, implementation and delivery plans, line-manages the engineers, and is the primary technical interface to our infrastructure partners.This is a hands-on infrastructure leadership role with a fixed delivery window in its first six months. It is not a research role, not a pure Kubernetes SRE role, and not a management-only role.Responsibilities Architecture. Own the platform architecture end to end: architecture proposals, high-level and low-level designs, driven through review and kept current as the baseline. Team leadership. Lead and line-manage a distributed team across backend (Node.js), frontend (React), DevOps, QA and documentation: engineering standards, code and design review, release gates, one-to-ones, growth and performance input. Bare-metal GPU scheduling layer. Design, build and operate a managed Slurm service for research users: controller and accounting, partitions and login nodes, node onboarding and acceptance, driver and CUDA baseline and upgrades, stalled-job and node-health detection, drain and autohealing, storage visibility, identity and isolation. Kubernetes control plane and GPU enablement. Own cluster bootstrap and lifecycle on partner-provided bare metal, NVIDIA GPU Operator and Network Operator, VM-based GPU isolation (KubeVirt and VFIO), and day-2 operations: upgrades, backup and recovery, node replacement. Managed inference at scale. Serving architecture, multi-GPU and multi-node parallelism, autoscaling, request routing and endpoint reliability; confidential-compute-capable capacity for sensitive workloads. Observability and operations. Metrics, logging, alerting and SLOs across control plane, GPU fleet and application tiers; incident response and post-incident review; an on-call model a small team can sustain. Partners and vendors. Primary technical interface to infrastructure partners and vendors: turning requirements into written specifications and acceptance tests, running escalations to closure, and providing technical input to capacity planning and hardware sourcing. Internal consumers. Work directly with research, model-training and product teams to translate their workloads into platform requirements, and broker capacity when it is short. Hiring. Complete the platform team and set the technical bar for the engineers who join it.