QA Engineer
Status
Barcelona, Spain
Full time
Office
Compensation is not specified
Role
QA Engineer
Description
Location: Barcelona, Spain
Experience Level: Mid Level
Job Function: Engineering
Type of Employment: Full-Time
Industry: Computer Network & Security
About the Company
Keyfactor specializes in Machine Identity, Certificate Lifecycle Management, and Public Key Infrastructure (PKI) Solutions, successfully expanding its reach in revenue, client base, and team size. Through simplifying PKI, automating certificate life cycle management, and promoting crypto-agility at scale, Keyfactor plays a critical role in helping security teams manage cryptography as essential infrastructure. After acquiring Redtrust in 2019, a well-respected Spanish company focused on digital certificate management for individuals, the collaborative efforts have enhanced the reputation of both organizations in Spain and Brazil.
The culture at Redtrust fosters both professional and personal growth, emphasizing continuous development and product excellence as key drivers for customer satisfaction. If you are enthusiastic about computer security and cryptography, seeking to contribute to a high-quality product, we invite you to explore this opportunity with us.
The role is based in Barcelona and offers a hybrid work arrangement. Candidates must possess a valid work permit in Spain.
Responsibilities
- Conduct quality assurance testing to uphold organizational standards in applications, products, and releases.
- Develop and execute test plans, scenarios, cases, and data with automation in mind, catering to different testing needs.
- Implement manual and automated test cases, document results and metrics, and provide feedback to the development team.
- Establish automated testing processes to enhance quality and performance.
- Collaborate with the development team on system defect identification, root cause analysis, and resolution.
Skills and Qualifications
Minimum Requirements:
- Substantial experience as a QA engineer or test engineer.
- Detail-oriented individual passionate about quality and continual improvement.
- Proficient in manual and automation testing tools such as Selenium, Junit, Cucumber, and API testing tools like Postman, SoapUI.
- Skilled in Java programming, test case/script planning, designing, and execution.
- Familiar with bug-tracking software like JIRA, TestRails, and Agile SCRUM methodologies.
- Fluent in English, both written and verbal communication.
Preferred Qualifications:
- Strong analytical, communication, and problem-solving abilities.
- Basic database understanding.
- Knowledge in operating platforms like Linux, Windows, Mac OS, iOS, Android, etc.
- Familiarity with .NET technology.
- University Engineering Degree in IT, SW Engineering, Computer Science, or related field is a plus.
Compensation
Salaries will be tailored to experience levels.
Culture, Career Growth, and Benefits
At Redtrust, we encourage continual advancement and personal development. It's a place where autonomy and structure coexist to foster an entrepreneurial spirit and stimulate creativity. This is further supplemented by various initiatives like comprehensive benefit coverage, a devoted Key Contributor & Culture Committee, participation in global volunteer activities, flexible time off, development and feedback sessions, and All-Hands meetings, among other perks.
Core Values
Our business ethos is rooted in core values that emphasize trust, customer-centricity, continuous innovation, agility, and teamwork to achieve collective success.
Equality and Accessibility
We are an equal opportunity employer committed to offering reasonable accommodation if needed. Contact us for more information.
Privacy Notice
Refer to our privacy notice for recruitment applicants for further details.
Strict adherence to removing links, hashtags, and additional information beyond editing content.
Skills Required
Keyfactor
Website
www.keyfactor.comCompany size
Not specified
Location
United States
Description
Not specified
Status
Marcus Lindberg
Senior Blockchain Engineer - Low-Latency Execution Infrastructure (HyperEVM / Hyperliquid)
Full time
Remote
we’re looking for a senior blockchain engineer to build low-latency execution infrastructure around hyperevm and hyperliquid-related trading systems.
this is not a frontend or dapp role. the focus is on real-time execution systems, chain-native infrastructure, and market-aware backend engineering where latency, ordering, and state correctness directly impact execution outcomes.
you will work on systems that operate under noisy, adversarial, and highly dynamic conditions, including delayed or missing websocket events, rpc inconsistencies, transaction lifecycle complexity, state desynchronization, retries, and recovery logic.
core responsibilities include building and maintaining realtime blockchain data pipelines, websocket and rpc streaming systems, execution orchestration layers, liquidity-aware routing logic, transaction lifecycle management, and integration with orderbook and market data systems.
we are specifically looking for engineers who think in systems rather than features. meaning understanding how data flows through pipelines, how state evolves over time, how failures propagate, and how to design systems that recover automatically without manual intervention.
areas of work include:
- realtime blockchain data ingestion
- mempool-aware execution flows
- transaction lifecycle handling
- execution sequencing and routing
- websocket and rpc infrastructure
- state synchronization systems
- liquidity and orderbook integration
- performance and latency optimization
you should be comfortable working with distributed systems, asynchronous event processing, and latency-sensitive backend architectures.
strong experience in one or more of the following areas is highly relevant:
- exchange infrastructure
- trading systems
- execution engines
- blockchain indexers
- realtime event systems
- arbitrage systems
- rpc/node infrastructure
- defi backend systems
- low-latency backend engineering
preferred technical stack:
- typescript / node.js
- go
- rust
- python
- postgres
- clickhouse
- redis
- kafka or similar messaging systems
- docker
- linux environments
- evm rpc internals
- websocket infrastructure
ecosystem familiarity:
- ethereum, arbitrum, base, optimism, bsc
- hyperliquid / hyperevm
- foundry
- ethers.js / viem
- geth / erigon / nethermind
- dex and amm mechanics
- liquidity math, slippage, gas strategy, routing logic
this role is not suitable for:
- frontend-only developers
- nft or basic dapp experience only
- tutorial-level web3 developers
- candidates without production systems experience
we value engineers who have built real systems where correctness, latency, and reliability matter under load. we care less about buzzwords and more about concrete systems you have personally built and operated.
ideal candidates can clearly explain:
- system architecture decisions
- bottlenecks and tradeoffs
- failure modes and recovery strategies
- latency considerations in real systems
- production debugging experience
working style:
- remote
- async-first
- low bureaucracy
- high ownership
- engineering-driven team
- direct technical communication
we strongly prefer practical engineering depth over polished presentation. if you have built or worked on systems involving realtime data, trading infrastructure, blockchain execution, or latency-sensitive backend systems, please include details of those systems when applying.
Payment in Crypto
TA Quant
Senior Rust Developer
Full time
Remote
About the Role
We're looking for a Senior Rust Developer to join our core engineering team and own the systems that sit closest to the market. This means low-latency order execution engines, high-throughput market data pipelines, real-time streaming infrastructure, and integrations with both centralized and decentralized exchanges. Every millisecond and every line of code matters here, and you'll be the person making sure it all holds up under pressure. This is not a role for someone who wants to write Rust adjacent to trading. You'll be building the backbone of live production systems where correctness, safety, and raw performance have direct P&L consequences. You'll work alongside quantitative researchers and other engineers to implement and deploy strategies, and you'll have meaningful input into the infrastructure decisions that shape how we build and scale. If you've spent years pushing Rust to its limits in high-performance environments and you want that work to matter in real markets in real time, this is the role.
Responsibilities
Design, build, and maintain high-throughput, low-latency trading systems in Rust
Develop and optimize order execution engines, market data feeds, and real-time processing pipelines
Build reliable integrations with centralized and decentralized exchanges across CEX and DEX environments
Architect systems for real-time streaming data and WebSocket communication at scale
Write safe, well-tested concurrent code leveraging async runtimes including Tokio and async-std
Collaborate with quantitative researchers to implement and deploy trading strategies into production
Profile, benchmark, and eliminate performance bottlenecks across critical system paths
Contribute to infrastructure decisions around deployment, observability, and fault tolerance
Requirements
5+ years of professional software engineering experience
2+ years building and maintaining production systems in Rust, and you will be tested on it
Deep command of Rust's ownership model, lifetimes, traits, and async patterns
Experience with high-performance networking including TCP/UDP, WebSockets, and gRPC
Strong understanding of concurrency primitives and lock-free data structures
Familiarity with financial systems, trading platforms, or real-time data pipelines
Linux systems programming and performance tuning experience
Comfortable working independently in a fast-paced, remote-first environment
Nice to Have
Experience with cryptocurrency exchanges, DeFi protocols, or blockchain RPC nodes
Knowledge of FIX protocol or other financial messaging standards
Open-source Rust contributions
Experience with FPGA or kernel-bypass networking such as DPDK or io_uring
Familiarity with quantitative trading concepts including order books and market microstructure
Infrastructure experience with Docker, Kubernetes, Terraform, or Prometheus/Grafana
We're looking for a Senior Rust Developer to join our core engineering team and own the systems that sit closest to the market. This means low-latency order execution engines, high-throughput market data pipelines, real-time streaming infrastructure, and integrations with both centralized and decentralized exchanges. Every millisecond and every line of code matters here, and you'll be the person making sure it all holds up under pressure. This is not a role for someone who wants to write Rust adjacent to trading. You'll be building the backbone of live production systems where correctness, safety, and raw performance have direct P&L consequences. You'll work alongside quantitative researchers and other engineers to implement and deploy strategies, and you'll have meaningful input into the infrastructure decisions that shape how we build and scale. If you've spent years pushing Rust to its limits in high-performance environments and you want that work to matter in real markets in real time, this is the role.
Responsibilities
Design, build, and maintain high-throughput, low-latency trading systems in Rust
Develop and optimize order execution engines, market data feeds, and real-time processing pipelines
Build reliable integrations with centralized and decentralized exchanges across CEX and DEX environments
Architect systems for real-time streaming data and WebSocket communication at scale
Write safe, well-tested concurrent code leveraging async runtimes including Tokio and async-std
Collaborate with quantitative researchers to implement and deploy trading strategies into production
Profile, benchmark, and eliminate performance bottlenecks across critical system paths
Contribute to infrastructure decisions around deployment, observability, and fault tolerance
Requirements
5+ years of professional software engineering experience
2+ years building and maintaining production systems in Rust, and you will be tested on it
Deep command of Rust's ownership model, lifetimes, traits, and async patterns
Experience with high-performance networking including TCP/UDP, WebSockets, and gRPC
Strong understanding of concurrency primitives and lock-free data structures
Familiarity with financial systems, trading platforms, or real-time data pipelines
Linux systems programming and performance tuning experience
Comfortable working independently in a fast-paced, remote-first environment
Nice to Have
Experience with cryptocurrency exchanges, DeFi protocols, or blockchain RPC nodes
Knowledge of FIX protocol or other financial messaging standards
Open-source Rust contributions
Experience with FPGA or kernel-bypass networking such as DPDK or io_uring
Familiarity with quantitative trading concepts including order books and market microstructure
Infrastructure experience with Docker, Kubernetes, Terraform, or Prometheus/Grafana
Payment in Crypto
Keras Labs
Senior Software Engineer
Full time
Remote
Role OverviewKeras Labs is seeking a high-performing Blockchain Engineer to design, build, and scale smart contract systems for a hybrid AMM + perpetual trading platform powered by AI agents.This role also includes building and deploying standard token contracts (ERC20/BEP20) and supporting core on-chain infrastructure in a fast-paced, product-driven environment. Core ResponsibilitiesBuild and maintain smart contracts (Solidity / Rust)Develop and deploy ERC20 / BEP20 (or equivalent EVM) tokensImplement token logic (minting, burning, access control)Build core protocol modules (liquidity, trading, vaults)Integrate price oracles and on-chain data sourcesOptimize contracts for gas efficiency and performanceCollaborate with frontend, product, and research teamsSupport testing, audits, and deployment workflowsMonitor protocol performance and on-chain activity RequirementsStrong proficiency in Solidity (EVM) and/or RustExperience deploying ERC20 / BEP20 or similar token standardsFamiliarity with smart contract testing (Foundry, Hardhat)Understanding of contract security best practicesStrong system design and problem-solving skillsComfortable working in a fast-paced, remote environment Nice to HaveExperience with DeFi protocols (DEX, perps, lending)Understanding of AMM models and perpetual mechanicsExperience building trading systems or financial primitivesExperience with oracles (Chainlink, Pyth, etc.)Exposure to AI agents or automated trading systemsOpen-source contributions in Web3 / DeFi Compensation & BenefitsPerformance Bonus: Annual incentive structureBenefits: Remote-first flexibility, high ownership, impact-driven culture
Payment in Crypto
TA Quant
Quantitative Researcher
Full time
Remote
We're looking for a Quant Researcher to join us remotely and take direct ownership of the research lifecycle, from raw data exploration all the way through to live strategy deployment. You'll work closely with our trading and engineering teams to develop, test, and continuously refine the models and algorithms that drive real P&L outcomes across crypto markets. This is a high-ownership role with meaningful exposure to live markets from day one. You won't be running support research in the background, you'll be a core contributor shaping the strategies we actually trade. That means working with large and often unconventional datasets, identifying exploitable statistical patterns in volatile and illiquid market conditions, and translating rigorous mathematical research into production-ready code that performs when it counts.
Responsibilities
Develop, backtest, and continuously improve quantitative trading models and algorithms, translating mathematical insights into production-ready code
Collaborate with trading and development teams to refine existing strategies and build new ones with a direct focus on P&L impact
Work through large and complex datasets to identify patterns, validate hypotheses, and stress-test models against real market conditions
Conceptualize valuation frameworks, improve mathematical models, and maintain strategy performance in live environments
Conduct ongoing statistical research into crypto market microstructure and price dynamics using both conventional and unconventional data sources
Requirements
Advanced degree in mathematics, statistics, physics, computer science, or a related quantitative field
Strong proficiency in probability and statistics, including time-series analysis, machine learning, and pattern recognition applied to financial data
Hands-on programming experience in Python, with familiarity in R or MATLAB and ideally some exposure to compiled languages like C++
Prior experience in crypto markets, digital asset trading, or algorithmic finance
Proven ability to work in a data-driven research environment with minimal direction
Rigorous, evidence-based approach to problem-solving with the ability to move quickly from hypothesis to testable implementation
Responsibilities
Develop, backtest, and continuously improve quantitative trading models and algorithms, translating mathematical insights into production-ready code
Collaborate with trading and development teams to refine existing strategies and build new ones with a direct focus on P&L impact
Work through large and complex datasets to identify patterns, validate hypotheses, and stress-test models against real market conditions
Conceptualize valuation frameworks, improve mathematical models, and maintain strategy performance in live environments
Conduct ongoing statistical research into crypto market microstructure and price dynamics using both conventional and unconventional data sources
Requirements
Advanced degree in mathematics, statistics, physics, computer science, or a related quantitative field
Strong proficiency in probability and statistics, including time-series analysis, machine learning, and pattern recognition applied to financial data
Hands-on programming experience in Python, with familiarity in R or MATLAB and ideally some exposure to compiled languages like C++
Prior experience in crypto markets, digital asset trading, or algorithmic finance
Proven ability to work in a data-driven research environment with minimal direction
Rigorous, evidence-based approach to problem-solving with the ability to move quickly from hypothesis to testable implementation
Payment in Crypto
Michael Har
Junior / Middle Metaverse Developer (Unity / Web3 / VR)
Manzhouli, China
Manzhouli, China
Full time
Remote
We are looking for a Metaverse Developer to help build interactive virtual environments and immersive digital experiences. The role involves developing 3D worlds, integrating Web3 technologies, and working with modern tools for real-time applications.
You will work with Unity, WebGL, and blockchain technologies to create engaging metaverse features and optimize them for performance across different devices. The developer will collaborate with designers and backend engineers to deliver scalable and stable products.
Requirements include experience with Unity and C#, understanding of 3D development, Web3 or blockchain basics, and familiarity with Git and API integration. Experience with VR/AR, NFTs, or multiplayer systems is a plus.
We offer remote work, flexible hours, crypto payments, and the opportunity to build innovative metaverse products.
You will work with Unity, WebGL, and blockchain technologies to create engaging metaverse features and optimize them for performance across different devices. The developer will collaborate with designers and backend engineers to deliver scalable and stable products.
Requirements include experience with Unity and C#, understanding of 3D development, Web3 or blockchain basics, and familiarity with Git and API integration. Experience with VR/AR, NFTs, or multiplayer systems is a plus.
We offer remote work, flexible hours, crypto payments, and the opportunity to build innovative metaverse products.
Payment in Crypto