
Senior backend developers
Minimum 5 years of experience
Backend skills: MongoDB, Node.js
Remote work available
(We prefer individual developers over agencies or IT providers)

About City Labs
About
City labs is a profitable company
Candid answers by the company
An all-in-one solution for the independent retailer:
- e-Commerce app
- Cashback loyalty program using our own CityCoin token
- Messaging
- and more
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Context for the Candidates:
Blockchain engineers are tasked with building secure, scalable, and high-performance decentralized applications. This discussion focuses on how to utilize key technologies—Node.js, Rust, Go, TypeScript, Ethers.js, viem, and Hardhat—in smart contract and blockchain system development, while addressing the practical challenges that arise in such projects.
Key Discussion Points:
• How do you integrate Node.js, Rust, Go, and TypeScript in blockchain-backed applications?
• Discuss the trade-offs between using Rust or Go for performance-critical blockchain services.
• What are the key challenges in ensuring the security and scalability of smart contracts using tools like Ethers.js, viem, and Hardhat?
• How do you approach testing, debugging, and deploying smart contracts in a decentralized environment?
• Share best practices for gas optimization, contract upgradability, and backend scalability.
Evaluation Criteria:
1. Technical Knowledge:
• Strong knowledge of Node.js, Rust, Go, and TypeScript with practical experience in blockchain development.
• Proficiency in Ethers.js, viem, Hardhat, and smart contract lifecycle (development, testing, deployment).
• Understanding of security best practices, performance optimizations, and scalability in decentralized systems.
2. Problem-Solving and Integration Skills:
• How candidates approach integrating smart contract solutions with backend services using Node.js, Rust, Go, and TypeScript.
• Solutions proposed for common challenges in blockchain projects such as gas fees, security vulnerabilities, and system bottlenecks.
3. Experience and Expertise:
• Minimum of 2 years of IT experience, including hands-on development with the specified technologies.
• Practical knowledge of blockchain architecture, consensus mechanisms, and decentralized application deployment.
4. Innovation and Critical Thinking:
• Candidates’ ability to think creatively about system architecture, proposing scalable and secure solutions for blockchain-based applications.
• Discussion on the future potential of blockchain technology and how the tech stack can evolve.
5. Communication and Team Collaboration:
• Clear articulation of technical challenges and how to address them in a team setting.
• Ability to lead or contribute to discussions in a way that encourages collaboration and team-driven problem-solving.

Sr. Software Developer ( 4years – 5years)
Required:
- Extensive experience in Ruby on Rails (4-5)years, software designing and architecture.
- Experience in microservice architecture (2-3)years
- Experience in Elastic Search/Redis/Sidekiq
- Experience in writing Rspec Test cases
- Experience in cloud services such as AWS
- Experience in Postgres/Mysql, Database Modelling
- Excellent problem solving capabilities
Good To have:
- Experience in design pattern
- Experience in managing teams
Mandatory Skills - 4 years in Nodejs, JavaScript, Express.js, MongoDB, Data Structures, Algorithms
"Expertise in Node.js Web frameworks like Meteor, Express, and Kraken.JS
Expertise in building highly scalable web services using Node.js, Create REST API with the help of Node middleware
Deep understanding of REST and API design
Experience designing APIs for consistency, simplicity, and extensibility.
Expertise with JavaScript testing frameworks like Jasmine, Quit, Mocha, Sinnon and Chai.
Expertise with building tools like Web pack, gulp, and grunt.
Integration of various application components
Experience in various phases of the Software Development Life Cycle (SDLC) such as requirements
analysis, design, and implementation in an agile environment, etc.
- 2+ year of experience in Development in JAVA technology.
- Strong Java Basics
- SpringBoot or Spring MVC
- Hands on experience on Relationl Databases (SQL query or Hibernate) + Mongo (JSON parsing)
- Proficient in REST API development
- Messaging Queue (RabitMQ or Kafka)
- Microservices
- Any Caching Mechanism
- Good at problem solving
Good to Have Skills:
- 4+ years of experience in using Java/J2EE tech stacks
- Good understanding of data structures and algorithms.
- Excellent analytical and problem solving skills.
- Ability to work in a fast paced internet start-up environment.
- Experience in technical mentorship/coaching is highly desirable.
- Understanding of AI/ML algorithms is a plus.
Merchify is a one-stop solution for creators to start their merch store for zero investment. Our goal is to empower creators to monetize their content and grow their audience without the need for any upfront investment.
We’re in search of a back-end engineer that specializes in building highly scalable, highly available, reliable, secure, and fault-tolerant systems. As a part of the Core Backend team, you'll be working on some complex and interesting problems. With a lean team like ours, you'll have ample opportunities to work with various aspects of the application and build something meaningful.
What you'll do?
- Work closely with design, product management, and front-end teams to create REST APIs using NestJS
- Write reusable, testable, and efficient code
- Design and implementation of low-latency, high-availability, and performant applications
- Work on the implementation of security and data protection
- Review and optimize the app usage by monitoring key metrics and rectifying the issues proactively
Must haves
- 1+ years of experience in NodeJS-based frameworks like NestJS, and microservices-based architecture is a bonus.
- Understanding of OOPS concepts, persistence, threading, queuing, and caching.
- Thorough knowledge of designing, implementing and scaling relational and document-based databases
- A love for systems and an ability to think through and plan for their life cycles, edge cases, interactions, and failure modes
- First principles thinking, Excellent problem-solving ability
- A good all-rounder with a can-do, startup mentality
Nice to haves
- Experience with ReactJS
- Cloud deployment and scaling experience
Why you should join today?
Merchify wants to make a change for the better in lifelong learning. By joining at the start of the adventure you will have an opportunity to make this your own baby and have fun shaping the future of the industry.
Responsibilities:
- Develop, implement, and maintain production timelines across multiple teams
- Translate product’s strategy into detailed requirements for prototype construction and final product development
- Analyze consumer needs, current market trends, and potential partnerships from an ROI
- Outline the product vision, product strategy, and product roadmap
- Assess current competitor offerings, seeking opportunities for differentiation
- Appraise new product ideas and strategize appropriate to-market plans
- Ensure that user story content and prioritization is aligned to the larger strategic objective
- Recommend the scope of present and future product lines by reviewing product specifications and appraising adjustments
- Provide information for management by preparing product sales forecasts and reports
- Meet regularly with key customer-facing teams to collect and analyze user feedback to shape new product ideas and user requirements.
- Help in the creation and maintenance of bona fide product documentation
- Work with development leads so that product requirements are understood and built accordingly
- Work within a software development methodology like AGILE
- Coordinate product releases with marketing, sales, and development teams
- Provide product training and technical expertise
- Work with the leadership team in planning the product roadmap.
- Be the product owner driving our strategic product and technology vision on the platform side of products
Requirement:
- 3+ years of experience as a Technical Products Manager in a software company.
- Has deep knowledge of every stage of the product life-cycle -- introduction, growth, maturity, and decline -- and understands how it affects development adjustments.
- Critical thinker & problem solver
- Familiarity in the AGILE development framework will be preferable.
- Strong understanding of cutting-edge tools and technologies for frontend and backend development
- Data-oriented, have exceptional analytical skills
- Experience working with the development teams directly will be a plus
- Has the ability to set priorities and resolve issues and set realistic product development goals
- Should be able to communicate technical solutions to both internal and external audiences
- Understand industry flow and trends
- Has the ability to evaluate key metrics to optimize performance
- Demonstrated track record managing successful product development from feature definition to project deployment
- Work with product management analytics tools
- A people-friendly person with extraordinary organizational and leadership skills
Responsibilities:
- Strong Technical Chops: You should know how to build highly scalable, robust, and fault-tolerant services that support our unique rate-of-growth requirements.
- You should be on top of the latest architectural trends.
- Fast Learners: We are looking for folks who thrive on new technologies and don't believe in one-size-fit all solutions.
- You should be able to adapt easily to meet the needs of our massive growth and rapidly evolving business environment.
- You understand requirements beyond the written word.
- Whether you're working on an API used by other developers, an internal tool consumed by our operation teams, or a feature used by millions of customers, your attention to details leads to a delightful user experience.
Requirements:
- Strong knowledge of MySQL, NoSQL, PostgreSQL, ElasticSearch.
- Experience in Java and web technologies.
- Experience in any one scripting language like Python.
- Hands-on experience with systems that are asynchronous, RESTful and demand concurrency.
- Knowledge of best software engineering practices for all stages of software development life cycle, including coding standards, code reviews, testing and deployment.
Backend - Software Development Engineer-III
Responsibilities:-
- Research, design and build highly reliable, available and scalable platforms
- Explore design implications and work towards an appropriate balance between functionality, performance, and maintainability.
- Lead by example, mentor and guide team members on everything from structured problem solving to development of best practices
- Own large technical deliverables and execute in an exemplary way
- Be able to conceptualize and develop prototype quickly
- Working with a cross-discipline team of Design, Product, Data Science and Analytics team.
- Active participation in the hiring process to bring quality engineers in the team.
Requirements:-
- Strong proficiency in Javascript and TypeScript
- Strong proficiency of Node.js and frameworks available for it such as Express
- Strong understanding and experience of creating highly scalable and complex database design
- Good understanding of Data Modeling using RDBMS and NoSQL(Cassandra, MongoDB, ElasticSearch, Redis) data stores
- Strong problem-solving skills with a good understanding of data structures and algorithms
- Strong understanding of front-end technologies, such as HTML5, and CSS3
- User authentication and authorization between multiple systems, servers, and environments
- Experience of creating highly scalable, fault tolerant, resilient distributed systems
- Strong knowledge of creating scalable system design and good understanding of microservice based architectures
- Understanding of caching enabled, PubSub and event driven architectures
- Hands on experience and good knowledge of AWS services
- Understanding automated testing platforms like selenium and unit tests like Chai, Mocha, Jasmine etc
- Proficient understanding of code versioning tools, such as Git
- E/B.Tech/M.E./M.Tech/M.S.
- Curiosity to explore the cutting edge technologies and bake them in the products.
- Zeal and drive to take end to end ownership.
- 5+ years of experience in back end development preferably in microservice environment.



