Senior Full Stack Engineer - NET ecosystem (545)
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Ubiminds is a company dedicated to putting people first and has received certification as a Great Place to Work. We specialize in collaborating with American software product firms to expand their development capabilities. Utilizing the top 5% of talent in Brazil, Ubi aids in their LATAM strategy through customized solutions, including staff augmentation and acting as an employer of record.
Ubiminds is currently supporting the growth of a SaaS company as it embarks on upgrading its technology platform and implementing scalable, AI-assisted software development methods. To facilitate this transition, they are increasing the size of their engineering team to construct secure, high-performance applications by utilizing contemporary architecture, cloud technologies, and AI-driven development workflows.
Challenge
We are seeking a Senior Full Stack Engineer experienced in the .NET ecosystem to assist in constructing scalable, secure, and high-performance SaaS applications.
In this position, responsibilities include hands-on software development, architecture and design tasks, resolving intricate technical issues, and devising technical solutions. Collaboration with diverse teams is essential to deliver dependable, top-notch software solutions, requiring proficiency in both backend and frontend technologies.
The ideal candidate demonstrates a keen interest in modern engineering practices, relishes tackling complex technical problems, and is enthusiastic about utilizing AI-powered tools to enhance productivity and software quality.
Responsibilities
Design, develop, and uphold scalable, secure, and high-performance SaaS applications.
Engage in architecture and technical design decisions across different layers of the application stack.
Create and maintain backend services using the .NET ecosystem.
Develop and manage modern web applications utilizing Angular.
Troubleshoot complex application issues and optimize system performance.
Design and enhance relational databases, SQL queries, and stored procedures.
Produce clean, sustainable, and well-tested code following engineering best practices.
Participate in planning, technical deliberations, and solution designs.
Operate in a Shift Left engineering environment with a strong commitment to software quality ownership.
Utilize AI-enhanced development tools to hasten software delivery and heighten engineering efficiency.
Mandatory Skills
Experience
A minimum of 5 years of professional experience creating web applications with C#, SQL, and Angular.
Proficiency in working with stored procedures, relational databases, and performance-sensitive SQL queries.
Possessionof a Bachelor's degree in Computer Science, Information Technology, Engineering, or a related field or equivalent practical experience.
Engineering Practices
Strong skills in troubleshooting, debugging, and optimizing performance.
Experience in writing unit and integration tests.
Comfortable working in a Shift Left development environment.
Strong dedication to delivering quality, reliable software.
Self-driven, proactive, and collaborative approach.
Excellent communication skills in English, both written and verbal.
AI & Modern Development
Willingness to adopt AI-powered development tools like GitHub Copilot, Cursor, and Claude Code Bar.
Basic to intermediate comprehension of modern AI concepts such as LLMs, MCP, RAG, and related technologies.
Nice to Have
Expertise in updating ASP.NET Web Forms or analogous server-rendered applications.
Proficiency in Microsoft SQL Server, including indexing and query optimization.
Knowledge of AWS services like EC2, S3, SES, or similar cloud platforms.
Exposure to modern API technologies like GraphQL.
Experience with coding agents or AI-supported development workflows.
Solid understanding of HTML and CSS in conventional web application settings.
Team & Environment
A collaborative engineering team focused on upgrading enterprise SaaS applications.
Robust engineering culture emphasizing quality, taking ownership, and continual enhancement.
Opportunities to engage with cutting-edge AI-enabled software development workflows.
Collaborative setting featuring architecture deliberations and cross-functional planning.
Fast-paced product organization with an emphasis on scalability, innovation, and engineering excellence.
About Ubiminds
Our Culture
Putting People First: People are at the core of everything we do.
Challenging Ourselves: We believe in continuous improvement.
Making Things Happen: We value attitude, responsibility, and commitment.
Standing Together: We work, grow, and evolve as a cohesive unit.
Aiming for Excellence: Delivering exceptional services and surpassing expectations.
Staying Real: Upholding honesty, transparency, and openness at all times.
Perks and Benefits
As a Senior Full Stack Engineer at Ubiminds, you:
Become part of a product-focused company and operate as a full-fledged team member.
Access our comprehensive back-office support including career guidance, HR, and concierge services.
Embrace our remote-first policy.
Receive your own MacBook to work on.
Participate in tech talks, chapter meetings, and join a vibrant community of top engineering professionals.
Enhance your English proficiency through complimentary lessons with a native English speaker.
Earn a referral bonus for recommending new Ubiminders.
Enjoy the option to work onsite at our Florianópolis headquarters, with perks like snacks, massages, drinks, and games.
[Contractor] Senior Blockchain Engineer
Among our clients, we have leading brands such as AB InBev, Singularity University, FINN and Tapcart. Our commitment to high-quality services has earned us recognition as the Top 1 Mobile Development company in Latin America and among the top 10 globally for Mobile App and Custom Software Development by Clutch and a GPTW-certified company for 10 years in a row.
The story behind this role
We’re continuously working with companies building ambitious digital products across Web2, Web3, AI, and emerging technologies. Many of our client engagements start with strategic conversations and evolve quickly into active projects.
That’s why we maintain a network of strong contractor engineers we can engage quickly when the right projects come in.
This is not a traditional long-term internal role.It’s a contractor opportunity designed for people who enjoy working across different products, clients, technologies, and business challenges in fast-moving environments.
We’re looking for a Blockchain Engineer (Contractor) who enjoys solving complex technical problems, navigating ambiguity, and contributing to real-world products used by companies across the US and Europe.
Engagement details
Contractor / project-based engagement
Paid in USD/hour
Flexible allocation depending on project availability and fit
Opportunities may vary in duration, scope, and weekly commitment depending on client needs
Some opportunities may start immediately. Others may become active as new projects enter our pipeline.
What this role actually looks like
This is not a “receive tasks and code” type of role.
On a typical project, you might:
Build and evolve blockchain infrastructure services that power production-grade digital asset platforms
Work closely with team members to figure out what should actually be built
Integrate backend systems with Layer-1 blockchains, ensuring reliability, scalability, and operational resilience
Build services such as blockchain indexers, event processors, chain APIs, wallet services, and transaction pipelines
Design and improve blockchain workflows around transaction execution, event monitoring, reconciliation, and failure recovery
Make trade-offs between scalability, security, observability, maintainability, and business priorities
Collaborate with international clients and multidisciplinary teams to shape technical solutions for security-critical blockchain products
What tends to work well here
We’ve seen that people who thrive in this type of engagement usually:
Have strong experience building or integrating blockchain infrastructure in production environments
Understand Layer-1 blockchain mechanics such as transaction lifecycle, confirmations, finality, forks, reorgs, and event propagation
Feel comfortable building backend services, APIs, event-driven systems, and distributed architectures beyond the blockchain layer itself
Have a fullstack mindset — even if blockchain and backend are your strengths, you're comfortable navigating adjacent technologies and collaborating across the stack when needed
Enjoy solving complex infrastructure problems where security, observability, and reliability matter as much as feature delivery
Feel totally confident working in English with international clients and teams (calls, discussions, async) — at least advanced level
Already use AI as part of their day-to-day workflow — whether for protocol analysis, development, debugging, documentation, testing, or workflow acceleration
This probably won’t be your thing if
Just to be transparent:
You’re looking for a highly stable long-term internal role with fixed scope and predictable allocation
You prefer highly structured environments with rigid processes and very defined requirements
You’re uncomfortable navigating ambiguity or fast-changing technical contexts
You’d rather avoid client interaction or cross-functional collaboration
You dislike context-switching between technologies, projects, and business domains
There’s nothing wrong with any of that — it’s just not how these engagements usually operate.
One last thing
To participate in this selection process, you must:
Have a valid business registration in your country (CNPJ, VAT, EIN, or equivalent)
Have a bank account eligible to receive USD payments
Be able to issue invoices accordingly
Be based in the USA
These requirements are necessary for contractor engagement and payment processing.
Not sure if you check every box?
That’s okay. We know that many great people — especially from underrepresented groups — hesitate to apply unless they meet 100% of the requirements.If this opportunity sounds interesting, we’d still love to hear from you.
LINK TO APPY: https://cheesecakelabs.hire.trakstar.com/jobs/fk0zr7h/
Chief Technology Officer (CTO) / Senior Full-Stack Developer (Web3)
We are building a next-generation Web3 social platform designed to redefine how digital communities connect, collaborate, and grow.
Backed by years of experience within the cryptocurrency, blockchain, and digital asset ecosystem, our team has developed deep insights into how founders, developers, investors, creators, and communities interact. This understanding inspired us to create a platform that goes beyond financial applications and focuses on empowering meaningful social engagement.
Our mission is to build a transparent, community-driven social network where users can share ideas, collaborate on projects, discover opportunities, and create lasting relationships. We believe the next evolution of social media will be powered by decentralized technologies while maintaining an exceptional user experience, simplicity, and long-term sustainability.
We are seeking an experienced Chief Technology Officer (CTO) or Senior Full-Stack Developer who is passionate about Web3 and capable of leading the technical vision, architecture, and execution of our platform from the ground up.
Responsibilities
Lead the technical strategy and product architecture.
Design and build scalable backend systems and modern frontend applications.
Develop high-performance APIs and real-time features.
Integrate blockchain technologies, wallets, and Web3 authentication where appropriate.
Build secure, reliable, and maintainable infrastructure.
Collaborate closely with product, design, and leadership teams.
Establish engineering best practices, code quality standards, and development workflows.
Mentor engineers and help grow the technical organization.
Evaluate emerging technologies and implement solutions that improve scalability, security, and user experience.
Requirements
5+ years of professional software development experience.
Strong experience with modern JavaScript/TypeScript ecosystems.
Experience with React, Next.js, Node.js, or similar technologies.
Solid understanding of system architecture, cloud infrastructure, databases, and API design.
Experience building scalable consumer-facing products.
Familiarity with blockchain technologies, Web3 infrastructure, wallets, smart contracts, or decentralized applications.
Strong knowledge of security best practices and application performance optimization.
Excellent problem-solving and communication skills.
Ability to work independently in a fast-paced startup environment.
Preferred Qualifications
Experience building Web3 or crypto products.
Understanding of decentralized identity, token ecosystems, or on-chain social applications.
Experience leading engineering teams or serving in a technical leadership role.
Background in DevOps, CI/CD, Docker, Kubernetes, or cloud platforms such as AWS or GCP.
Experience with real-time messaging, social platforms, or community products.
What We Offer
Competitive full-time compensation.
Opportunity to build a product from an early stage with significant technical ownership.
Flexible and remote-friendly work environment.
Collaborative team focused on innovation and long-term impact.
Work on cutting-edge Web3 technologies and help shape the future of digital communities.
Opportunity for career growth and leadership as the platform scales.
If you are excited about building the next generation of Web3 social experiences and want to make a meaningful impact from the earliest stages, we'd love to hear from you.
Senior Blockchain Engineer (Cosmos SDK & IBC)
Expectations:
Design custom modules (x/staking, x/rewards, x/merkl)
Implement IBC light clients and relayers
Optimize block time and state pruning
Write comprehensive unit & integration tests (Go test)
Build CLI tools for validators and delegators
Monitor node health and network upgrades
Collaborate with the research team on MEV-resistant ordering
Maintain chain upgrades (v1 → v2) with migration scripts
Write technical documentation for external validators
Nice to have:
Experience with Avalanche Subnets or Polkadot Substrate
Knowledge of HSM and key management
Open-source contributions to Cosmos SDK or related repos
Chinese+English language proficiency
Smart Contract Engineer (Solidity / Rust)
Expectations:
Design and deploy upgradeable proxy contracts (UUPS)
Write high-assurance tests with invariant testing (Foundry)
Implement access control (Ownable2Step, roles)
Integrate with Chainlink Automation and CCIP
Write Natspec docs and deployment scripts
Participate in internal security reviews and bug bounties
Optimize storage layouts to reduce gas costs by >15%
Collaborate with the research team on novel staking mechanisms
Nice to have:
Experience with LayerZero or Hyperlane
Published audit reports or contest wins (Code4rena / Sherlock)
Knowledge of ZK-proofs (basic)
Chinese language proficiency
Senior Blockchain Engineer - Low-Latency Execution Infrastructure (HyperEVM / Hyperliquid)
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.