Senior Software Engineer
Barcelona, Spain
Full time
Office
Compensation is not specified
Role
Software Engineer
Description
About Keyfactor
Our goal is to create a connected society built on trust, with a focus on identity-first security for both machines and humans. Keyfactor is dedicated to helping organizations quickly establish and maintain digital trust at scale. With over 1,500 trusted clients globally, we are consistently recognized as a Best Place to Work, thanks to our exceptional team nurturing our culture as we expand. We invite you to consider a future with Keyfactor!
Location: Spain; Barcelona
Experience Requirements: IC4 – Advanced
Job Function: Engineering
Employment Type: Full-Time
Industry: Computer & Network Security
Brief Overview
As a Senior Software Engineer at Keyfactor, you will be responsible for developing and maintaining software applications, implementing new features, and ensuring quality code. This role also involves collaborating with team members to design and troubleshoot complex solutions.
Key Responsibilities
- Develop, implement, and maintain software features and functions
- Conduct code reviews, pull requests, and ensure coding standards compliance
- Collaborate with cross-functional teams to solve complex problems
- Contribute to enhancing software development processes and practices
- Identify and resolve technical issues and performance bottlenecks
- Support and guide junior engineers
- Work closely with Quality Assurance teams when needed
- Participate in both internal and external product support
- Assist in technical documentation and project reporting
- Engage in Agile ceremonies and contribute to iterative development processes
Minimum Qualifications, Education, and Skills
- Bachelor’s degree in Computer Science, Engineering, or related field, or equivalent experience
- Strong background in software engineering or related field
- Strategic thinking, strong problem-solving skills, and proficiency in relevant tools and technologies
- Proficiency in design patterns, strong architectural skills, and advanced debugging capabilities
- Experience leading complex projects and driving strategic initiatives
- Ability to mentor team members, take on complex tasks, and encourage technical improvements
- Deep understanding of industry trends, company strategy, and cross-functional processes
- Extensive knowledge of software architecture principles, code optimization, and continuous integration practices
Compensation
Salary is based on experience and will be commensurate.
Culture, Career Opportunities, and Benefits
At Keyfactor, we continually strive to improve and offer opportunities for personal and professional growth. We provide a balance of autonomy and structure to foster an entrepreneurial environment that encourages creativity and innovation. Our initiatives support our special culture:
- Second Fridays (company-wide day off on the second Friday of every month)
- Comprehensive benefit coverage for you and your dependents
- Generous paid parental leave
- Employee-focused initiatives like Key Contributors & Culture Committees
- DIVERSE Commitment for inclusivity and diversity promotion
- Wellbeing resources, mindfulness app membership, Wellness Wednesdays
- Global Volunteer Day, volunteer time off, and company non-profit matching
- Unlimited time off (US) and competitive paid time off globally
- Monthly talent development and Cross Functional meetings for professional growth
- Regular All Hands meetings with group gatherings
Core Values
Our core values are central to how we operate and what we look for in every team member. They are:
- Trust is paramount
- Customers are core
- Innovation never stops, it only accelerates
- We deliver with agility
- United by respect
- Teams make "it" happen
Keyfactor is an equal opportunity employer, including veterans and individuals with disabilities.
Reasonable Accommodation: Applicants with disabilities can contact the People team for accommodation arrangements.
Stay Safe. Be Kind. Brush your hair before the Zoom call!
Skills Required
Keyfactor
Website
www.keyfactor.comCompany size
Not specified
Location
United States
Description
Not specified
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
Sirex
Junior/Mid Decentralized Infrastructure Engineer
Full time
Remote
Role:
Help build and scale decentralized infrastructure: contribute to compute networks, protocols, storage layers, and orchestration tools that power AI agents and open digital systems. You’ll write code, run tests, fix bugs, and ship real features fast.
Skills & Requirements:
1–3 years in blockchain infra, distributed systems, or high-scale compute (or strong personal projects)
Solid Python / Rust / Go skills
Interest in libp2p, IPFS, GPU orchestration, or decentralized compute
Quick learner who ships clean code and loves performance/cost challenges
Salary:
$110,000 – $165,000 USD base + meaningful equity (portfolio startup) + full benefits + Sirex carry
Description:
Sirex.vc doesn’t just invest — we plug strong builders straight into our portfolio companies.
This is your chance to work on the real infrastructure behind autonomous agents and the open digital economy. Full support from the Sirex team, fast growth, zero bureaucracy.
High risk. Zero apologies.
Help build and scale decentralized infrastructure: contribute to compute networks, protocols, storage layers, and orchestration tools that power AI agents and open digital systems. You’ll write code, run tests, fix bugs, and ship real features fast.
Skills & Requirements:
1–3 years in blockchain infra, distributed systems, or high-scale compute (or strong personal projects)
Solid Python / Rust / Go skills
Interest in libp2p, IPFS, GPU orchestration, or decentralized compute
Quick learner who ships clean code and loves performance/cost challenges
Salary:
$110,000 – $165,000 USD base + meaningful equity (portfolio startup) + full benefits + Sirex carry
Description:
Sirex.vc doesn’t just invest — we plug strong builders straight into our portfolio companies.
This is your chance to work on the real infrastructure behind autonomous agents and the open digital economy. Full support from the Sirex team, fast growth, zero bureaucracy.
High risk. Zero apologies.
Payment in Crypto
Neonflick
Web3 Fullstack Developer
Part time
Remote
🌐 About Us
Neonflick is a tech organization specializing in Web3 development.
We believe Web3 solutions are not as popular as they could be — mainly due to complexity. Our mission is to simplify the user experience and make decentralized technology more accessible and easy to use for everyone.
🚀 About the Role
We are looking for a Web3 Fullstack Developer who is passionate about decentralized technologies and excited to contribute to building meaningful Web3 products. You will work on developing new products, improving existing ones, and fixing bugs, all while proposing innovative ideas to enhance our platform.
🔹 Responsibilities
Develop functional and user-friendly Web3 products
Improve and optimize existing products and features
Identify and fix bugs or issues in the system
Propose and implement new ideas for product development
Collaborate with the team to ensure high-quality software delivery
🔹 Requirements
Strong interest in Web3 / blockchain / decentralized technologies
Fullstack development experience (frontend + backend)
Experience with smart contracts and decentralized frameworks is a plus
Problem-solving skills and attention to detail
Ability to work independently and proactively
🔹 What You Get
Early-stage involvement in a Web3 tech organization
Influence over product development and feature design
Opportunity to build experience and a portfolio in the Web3 space
Potential long-term collaboration and future compensation as the project grows
A chance to contribute to making Web3 simpler and more accessible
⚠️ Important
This is an unpaid position. We are looking for someone motivated by vision, learning, and long-term impact rather than immediate salary.
If you are passionate about Web3 and building meaningful decentralized products, we’d love to hear from you.
Neonflick is a tech organization specializing in Web3 development.
We believe Web3 solutions are not as popular as they could be — mainly due to complexity. Our mission is to simplify the user experience and make decentralized technology more accessible and easy to use for everyone.
🚀 About the Role
We are looking for a Web3 Fullstack Developer who is passionate about decentralized technologies and excited to contribute to building meaningful Web3 products. You will work on developing new products, improving existing ones, and fixing bugs, all while proposing innovative ideas to enhance our platform.
🔹 Responsibilities
Develop functional and user-friendly Web3 products
Improve and optimize existing products and features
Identify and fix bugs or issues in the system
Propose and implement new ideas for product development
Collaborate with the team to ensure high-quality software delivery
🔹 Requirements
Strong interest in Web3 / blockchain / decentralized technologies
Fullstack development experience (frontend + backend)
Experience with smart contracts and decentralized frameworks is a plus
Problem-solving skills and attention to detail
Ability to work independently and proactively
🔹 What You Get
Early-stage involvement in a Web3 tech organization
Influence over product development and feature design
Opportunity to build experience and a portfolio in the Web3 space
Potential long-term collaboration and future compensation as the project grows
A chance to contribute to making Web3 simpler and more accessible
⚠️ Important
This is an unpaid position. We are looking for someone motivated by vision, learning, and long-term impact rather than immediate salary.
If you are passionate about Web3 and building meaningful decentralized products, we’d love to hear from you.
Sirex
Junior AI Engineer
Full time
Remote
Role:
Join one of our fast-growing portfolio startups and help build simple AI features. You’ll work with large language models, create basic automations and chat tools, test ideas, fix small bugs, and integrate AI into everyday products.
Skills & Requirements:
0–2 years of experience (fresh graduates or self-taught welcome)
Basic Python knowledge
Interest in AI, LLMs or chatbots (personal projects are a big plus)
Quick learner who enjoys trying new things
Good English for team communication
Salary: $95,000 – $135,000 USD base + equity in the startup + full benefits
Description:
Sirex.vc not only invests — we actively help our portfolio companies hire great people. This Junior AI Engineer role is inside one of our AI-native startups. You’ll get real hands-on experience, learn from the best, and build things users actually use — all with full support from the Sirex team.
High risk. Zero apologies.
Join one of our fast-growing portfolio startups and help build simple AI features. You’ll work with large language models, create basic automations and chat tools, test ideas, fix small bugs, and integrate AI into everyday products.
Skills & Requirements:
0–2 years of experience (fresh graduates or self-taught welcome)
Basic Python knowledge
Interest in AI, LLMs or chatbots (personal projects are a big plus)
Quick learner who enjoys trying new things
Good English for team communication
Salary: $95,000 – $135,000 USD base + equity in the startup + full benefits
Description:
Sirex.vc not only invests — we actively help our portfolio companies hire great people. This Junior AI Engineer role is inside one of our AI-native startups. You’ll get real hands-on experience, learn from the best, and build things users actually use — all with full support from the Sirex team.
High risk. Zero apologies.
Payment in Crypto
Amir F
Full Stack Developer – Kick-to-Earn Gaming Platform
Istanbul, Türkiye
Istanbul, Türkiye
Full time
Remote
About the Project
We're building a mobile-first competitive gaming platform where players step onto the virtual field and earn rewards through penalty kick matches. The platform includes real-time gameplay, tournaments, leaderboards, an in-app store, token management (deposit/withdraw), daily quests, and a player progression system. Think casual gaming meets Web3 — fast, competitive, and rewarding.Current StateThe frontend is actively under development with a strong foundation already in place:
~30+ reusable UI components (modals, tabs, cards, buttons, inputs, badges, etc.)
Multiple feature modules: penalty game, tournaments, leaderboard, user profiles, store, token management
Figma-driven design system with a polished dark-themed UI
Animated goalkeeper characters using Lottie/dotLottie with SVG body parts
SPA routing and responsive mobile-first layouts
Tech Stack
Frontend: Next.js 16, React 19, TypeScript, Tailwind CSS 4
Animations: Lottie / dotLottie
Design Pipeline: Figma with MCP integration for design-to-code workflow
Tooling: ESLint, PostCSS, Turbopack
What You'll Do
Build and maintain frontend features with pixel-accurate implementation from Figma designs
Architect and develop backend services (APIs, authentication, game logic, matchmaking, token transactions)
Integrate blockchain/token functionality for the earn-and-spend economy
Design and manage the database layer (user data, match results, tournament state, transaction history)
Set up real-time infrastructure for live matches and leaderboard updates
Write clean, scalable TypeScript across the full stack
Collaborate closely with design to maintain high visual fidelity
Requirements
3+ years of production experience with React and Next.js
Strong TypeScript skills
Solid backend experience (Node.js, Express/Fastify/Hono, or similar)
Database design and management (PostgreSQL, MongoDB, or equivalent)
Experience building and consuming REST or GraphQL APIs
Understanding of real-time systems (WebSockets, SSE, or similar)
Proficiency with Tailwind CSS and responsive, mobile-first design
Comfort working from Figma designs with attention to detail
Nice to Have
Experience with Web3 / blockchain integrations (wallet connection, token transactions)
Familiarity with Lottie animations and interactive game-like UIs
Experience with matchmaking or game server architecture
Knowledge of payment/transaction systems
Experience with CI/CD pipelines and deployment (Vercel, Docker, etc.)
If you enjoy building products at the intersection of gaming and crypto, and you care about clean architecture and polished UI, we'd love to hear from you.Feel free to adjust the engagement type, compensation details, timezone preferences, and any company-specific info before posting.
We're building a mobile-first competitive gaming platform where players step onto the virtual field and earn rewards through penalty kick matches. The platform includes real-time gameplay, tournaments, leaderboards, an in-app store, token management (deposit/withdraw), daily quests, and a player progression system. Think casual gaming meets Web3 — fast, competitive, and rewarding.Current StateThe frontend is actively under development with a strong foundation already in place:
~30+ reusable UI components (modals, tabs, cards, buttons, inputs, badges, etc.)
Multiple feature modules: penalty game, tournaments, leaderboard, user profiles, store, token management
Figma-driven design system with a polished dark-themed UI
Animated goalkeeper characters using Lottie/dotLottie with SVG body parts
SPA routing and responsive mobile-first layouts
Tech Stack
Frontend: Next.js 16, React 19, TypeScript, Tailwind CSS 4
Animations: Lottie / dotLottie
Design Pipeline: Figma with MCP integration for design-to-code workflow
Tooling: ESLint, PostCSS, Turbopack
What You'll Do
Build and maintain frontend features with pixel-accurate implementation from Figma designs
Architect and develop backend services (APIs, authentication, game logic, matchmaking, token transactions)
Integrate blockchain/token functionality for the earn-and-spend economy
Design and manage the database layer (user data, match results, tournament state, transaction history)
Set up real-time infrastructure for live matches and leaderboard updates
Write clean, scalable TypeScript across the full stack
Collaborate closely with design to maintain high visual fidelity
Requirements
3+ years of production experience with React and Next.js
Strong TypeScript skills
Solid backend experience (Node.js, Express/Fastify/Hono, or similar)
Database design and management (PostgreSQL, MongoDB, or equivalent)
Experience building and consuming REST or GraphQL APIs
Understanding of real-time systems (WebSockets, SSE, or similar)
Proficiency with Tailwind CSS and responsive, mobile-first design
Comfort working from Figma designs with attention to detail
Nice to Have
Experience with Web3 / blockchain integrations (wallet connection, token transactions)
Familiarity with Lottie animations and interactive game-like UIs
Experience with matchmaking or game server architecture
Knowledge of payment/transaction systems
Experience with CI/CD pipelines and deployment (Vercel, Docker, etc.)
If you enjoy building products at the intersection of gaming and crypto, and you care about clean architecture and polished UI, we'd love to hear from you.Feel free to adjust the engagement type, compensation details, timezone preferences, and any company-specific info before posting.
Payment in Crypto