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Upstaff

Software Engineers to Boost your Product Development

Businesses who unlock the full performance potential of a world’s engineering talent gain a competitive edge and outperform the competition.
Upstaff
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valtech
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valtech
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adidas
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valtech
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1064 Available Talents

Steven Blockchain Software Engineer

Blockchain and Cryptography Engineer, Smart Contracts with Solidity Engineer, Smart Contracts with Rust Engineer, NFT Marketplace Developer, DeFi Ecosystem Developer

- Fast-paced, high-quality, detail-oriented, and self-motivated developer with more than 10 years of experience in the IT industry; - I use the TDD approach for designing the architecture and implementing scalable and maintainable web apps/services. - I have been working on a bunch of projects and meanwhile, I worked in several positions across frontend developer, backend developer, full-stack developer, and lead engineer; - In-depth skills develop smart contracts on Solidity; - Good skills working with Go; - 3 years experience with Rust; - 2 years experience with Substrate; - Smart contracts in complex DeFi and DEX structure; - Bridge Smart Contract which is for transferring tokens across networks; - Proxy smart contract; - eWallet App and GSM e-commerce product; - Blockchain networks including Cosmos, Ethereum, BSC, Polygon, Avalanche and Solana; - 5+ years experience with Node.js; - Deep skills working with Apollo GraphQL; - Good abilities working with Hardhat framework; - Deploy and work on various kinds of tokens - ERC20, ERC721, ERC721A, ERC1155; - Cross-chain smart contracts using LayerZero; - NFT Dapps such as madlab, Art Basel, Fateful Youth; - NFT market smart contract for auction and offer with lazy minting; - NFT marketplace Dapp using Venly; - Available: ASAP.

Solidity

Solidity

Go

Go   3.0 yr.

Node.js

Node.js   5.0 yr.

english

B2 (Upper-Intermediate) English

seniority

Senior (5-10 years)

location

China (UTC+08:00)

Last Updated: 4 Jul 2023

ID: 600-069-014
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Reliable and Easy as Amazon Purchase or Uber Ride

Check 1-3 Days before you see the first candidates available to start within 1-2 weeks (vs 1-2 months average hiring period)
Check You get pre-screened, vetted, properly selected candidates matching your requirements
Check No long-term commitment is required
Check Pre-defined termination, no issues with employee termination
Reliable and Easy as Amazon Purchase or Uber Ride
Check 1-3 Days before you see the first candidates available to start within 1-2 weeks (vs 1-2 months average hiring period)
Check You get pre-screened, vetted, properly selected candidates matching your requirements
Check No long-term commitment is required
Check Pre-defined termination, no issues with employee termination

Our Clients See Results

0%
See an increase in qualified candidates
0%
say that 50+ hours of engineering team time saved per developer on interviewing.
0%
Say their hiring process is now faster
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Upstaff Model Comparison

Upstaff

Faster

Upstaff gives 1-3 Days before you see the first candidates available to start within 1-2 weeks

Supervision

Engineer gets on-boarded. Upstaff team keeps supervising

More Scalable

Together we identify project requirements and ideal candidate profile

Easier

You review profiles & meet only few pre-screened finalists to decide who will be join your team

In-house Recruitment

Item Slower
Item Less Flexible

External Recruiter

Item Less Full Service
Item Without Supervision

Outsourcing Company

Item Less Scalable, Expensive
Item Professionalism & Quality

Freelancers / Upwork

Item More Difficult
Item Less Reliable

Case Study

E-commerce traffic management system

Company: NDA
Industry: E-commerce Location: Germany
802.1X

802.1X

Adobe CQ

Adobe CQ

AEM 6.4

AEM 6.4

Agile Project Management

Agile Project Management

Airtable

Airtable

About the client

The client is the key provider of smart web traffic management solutions, partnering with 52+ businesses across Europe — from enterprise companies to government applications.

Read More
Challenge

As the client has already worked with high volumes of data, the goal was to grow the web traffic, expand the network of partners, and transfer the project into an offline mode. It meant putting higher pressure on the network, which threatened to disrupt the entire system.

Solution

Our engineers discovered why servers crashed, fixed bugs that influenced web servers’ performance, and dealt with issues that interrupted the proper functioning of databases.

Key outcomes
  • Engineers updated the servers’ environment, infrastructure, and architecture of the database system, which let the system handle higher volumes of data
  • The traffic grew x3 in 4 months, which allowed the client to process over 5 million transactions daily

Landscape management solutions

Company: NDA
Industry: Landscape services Location: USA
Adobe Creative Suite

Adobe Creative Suite

Adobe CQ

Adobe CQ

Adobe After Effects

Adobe After Effects

Adobe Acrobat X

Adobe Acrobat X

Adobe Experience Manager (AEM)

Adobe Experience Manager (AEM)

Adobe indesign

Adobe indesign

About the client

The company has been serving facility professionals who manage various commercial properties since 1995. They offer a complex solution that covers site planning, mapping, and bonding, adding value by simplifying all ground management into one contract.

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Challenge

The client engaged our team when he needed to develop a new version of the landscaping operating software that’d manage the client’s contractors and subcontractors for groundworks. The challenge was to switch to the multitenant architecture in 2 months.

Solution

The client engaged our team when he needed to develop a new version of the landscaping operating software that’d manage the client’s contractors and subcontractors for groundworks. The challenge was to switch to the multitenant architecture in 2 months.

Key outcomes

The client engaged our team when he needed to develop a new version of the landscaping operating software that’d manage the client’s contractors and subcontractors for groundworks. The challenge was to switch to the multitenant architecture in 2 months.

  • As our engineers achieved the goal in time, it gave space to move to the backlog tasks and develop new features
  • The team started preparing the system for switching to React, moving towards a yearly goal

French Luxury Brand

Company: NDA
Industry: Fashion Location: Paris
AbodeXD

AbodeXD

Active Directory

Active Directory

Active model serializer

Active model serializer

Active Server Pages (ASP)

Active Server Pages (ASP)

Adapt-Framework

Adapt-Framework

Ad-hoc testing

Ad-hoc testing

Actix Web

Actix Web

CSS

CSS

About the client

Being a world-class fashion house, our client offers chic clothing, bags, and jewelry, putting everyone who touches the brand in the lap of luxury. Headquartered in France, the company is among founding fathers of haute couture — one-of-a-kind, impeccable design.

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Challenge

The company operates in 25 states with hundreds of stores and millions of customers worldwide. Enlarging the services, the client was lacking experienced PWA developers to refine its Magneto extensions on a regional website.

Solution

In just a week, developers kicked off the project and started working with Magento 2 and PWA Studio. The ultimate goal was to implement and develop custom modules and extensions. After six months of cooperation, the team presented shiny custom modules developed from scratch.

Key outcomes

As engineers worked on the project, the regional website performance along with the user engagement have increased.

  • The usability of the website was refined, which increased conversion rates by 10%
  • Overall user engagement grew by 35% while drop offs rate got lower
  • The brand got time to develop in other directions, continuing to grow its services

FAQ

What is Upstaff? Arrow

Upstaff is a service company with its own in-house engineering, and management competence, leveraging the community of software development companies’ resource network.

In what way are your different from other companies, agences, development shops Arrow

Upstaff can be imagined as Uber for software development. We provide managed which cost less than freelance marketplaces.

Is Upstaff a marketplace? Arrow

Upstaff is a service company that builds and manages distributed software engineering teams, and we use our own marketplace for sourcing.

Why are you so swift in finding candidates? Arrow

We have a widespread network of international partners and an up-to-date database of pre-vetted engineers.

What if your candidate doesn`t match our requirements? Arrow

It is possible to quickly offer a substitute.

When can my team start work? Arrow

Our developers can start immediately or within two weeks after the project is confirmed.

Is it possible to hire a whole team? Arrow

Yes.

Are your talents reliable professionals? Arrow

Our talents have experience in big international projects. They have proved to be reliable team players. Their tech and soft skills a verified. They all sign an NDA contract before they start work.

Do you need extra motivation to engage your candidates in the project? Arrow

You don’t need to worry about additional motivation in a form of bonuses, health insurance and other perks. All things are already included in the candidate’s contract with us. You only pay the agreed hourly rate.

We worry that your remote developer might not successfully fit in our team ? Arrow

We closely take into account the location of your company, its team composition and some other specific and sensitive moments.

Our managers select the most suitable candidates to avoid potential conflicts.

Reviews
Henry Akwerigbe
Henry Akwerigbe
This is a super team to work with. Through Upstaff, I have had multiple projects to work on. Work culture has been awesome, teammates have been super nice and collaborative, with a very professional management. There's always a project for you if you're into tech such Front-end, Back-end, Mobile Development, Fullstack, Data Analytics, QA, Machine Learning / AI, Web3, Gaming and lots more. It gets even better because many projects even allow full remote from anywhere! Nice job to the Upstaff Team 🙌🏽.
Vitalii Stalynskyi
Vitalii Stalynskyi
I have been working with Upstaff for over a year on a project related to landscape design and management of contractors in land design projects. During the project, we have done a lot of work on migrating the project to a multitenant architecture and are currently working on new features from the backlog. When we started this project, the hiring processes were organized well. Everything went smoothly, and we were able to start working quickly. Payments always come on time, and there is always support from managers. All issues are resolved quickly. Overall, I am very happy with my experience working with Upstaff, and I recommend them to anyone looking for a new project. They are a reliable company that provides great projects and conditions. I highly recommend them to anyone looking for a partner for their next project.
Владислав «Sheepbar» Баранов
Владислав «Sheepbar» Баранов
We've been with Upstaff for over 2 years, finding great long-term PHP and Android projects for our available developers. The support is constant, and payments are always on time. Upstaff's efficient processes have made our experience satisfying and their reliable assistance has been invaluable.
Roman Masniuk
Roman Masniuk
I worked with Upstaff engineers for over 2 years, and my experience with them was great. We deployed several individual contributors to clients' implementations and put up two teams of upstaff engineers. Managers' understanding of tech and engineering is head and shoulders above other agencies. They have a solid selection of engineers, each time presented strong candidates. They were able to address our needs and resolve things very fast. Managers and devs were responsive and proactive. Great experience!
Yanina Antipova
Yanina Antipova
Хочу виразити велику подяку за таку швидку роботу по підбору двох розробників. Та ще й у такий короткий термін-2 дні. Це мене здивувало, адже ми шукали вже цілий місяць. І знайдені кандидати нам не підходили Це щось неймовірне. Доречі, ці кандидати працюють у нас і зараз. Та надать приклад іншим працівникам. Гарного дня!)
Наталья Кравцова
Наталья Кравцова
I discovered an exciting and well-paying project on Upstaff, and I couldn't be happier with my experience. Upstaff's platform is a gem for freelancers like me. It not only connects you with intriguing projects but also ensures fair compensation and a seamless work environment. If you're a programmer seeking quality opportunities, I highly recommend Upstaff.
Volodymyr
Volodymyr
Leaving a review to express how delighted I am to have found such a great side gig here. The project is intriguing, and I'm really enjoying the team dynamics. I'm also quite satisfied with the compensation aspect. It's crucial to feel valued for the work you put in. Overall, I'm grateful for the opportunity to contribute to this project and share my expertise. I'm thrilled to give a shoutout and recommendation to anyone seeking an engaging and rewarding work opportunity.
Discover our Talent Experience
Discover our Talent Skills

Go (Golang) Ecosystem Arrow

R Frameworks and Libraries Arrow

Rust Frameworks and Libraries Arrow

Data Technologies/Analysis/Visualization Arrow

Decision Tree HBase KibanaKibana Logistic regression Random Forest TableauTableau Apache ZooKeeper Periscope Apache Oozie Business Intelligence (BI) Tools Data AnalysisData Analysis Apache AirflowApache Airflow Data modeling Kimbal Apache Spark Streaming Azure Data Factory Azure Databricks Apache HiveApache Hive Apache SparkApache Spark Business Analysis Google AnalyticsGoogle Analytics Apache Spark ML AWS Athena Data Modeling Pentaho Jupyter Notebook TalendTalend Data Modelling MapReduce Apache Oozie 4 Apache Spark 2 Impala Apache Pig Sqoop Data visualization MLML Nonlinear Dynamics Modelling Chaos Theory Own Development Forecasting Algorithms Multi-Models Forecasting Systems Nearest Neighbors Ridge Regression Cluster Analysis Factor Analysis Principal Component Analysis Linear and Nonlinear Optimization Basic Statistical Models Apache Nifi Google Spreadsheets Requirements Analysis Data Mining & AnalyticsData Mining & Analytics Microsoft Power BIMicrosoft Power BI LucidCharts Data Mining Elastic Search Platform Data Scraping Map Reduce DataDriven Model Interpretation Data Testing SAP Crystal Reports Flume Oozie Presto S3 domo Hunk Attunity Snaplogic Regression ELT Fivetran Linear Regression k-nearest neighbors algorithm (k-NN) K-Means clustering problem solving Pentaho Data Integration (Pentaho DI) Artificial neural networks for forecasting Classification Data Analysis Expressions (DAX) Protocol Buffers (Protobuf) Naïve Classification Bayes Classification SVM Classification Multiple Linear Regression Data Quality Technical Analysis Operations analysis Microsoft Azure Synapse Analytics Accumulo Looker Data Studio Cloudera Microsoft Purview Azure Data Lake Storage Azure Synapse Analytics

Databases & Management Systems / ORM Arrow

Apache CassandraApache Cassandra AWS ElasticSearchAWS ElasticSearch Eloquent ORM FirebaseFirebase Apache HadoopApache Hadoop HibernateHibernate MongoDBMongoDB MySQLMySQL NoSQLNoSQL Oracle DatabaseOracle Database PostgreSQLPostgreSQL RedisRedis RethinkDB SQLSQL SQLAlchemy SQLiteSQLite Snowflake Percona MariaDBMariaDB MemcachedMemcached MS Access Microsoft SQL ServerMicrosoft SQL Server PL/SQL SQL (DataGrip) AWS Redshift Greenplum Teradata Apache Spark Streaming RDBMS Azure Cosmos DB Hadoop ecosystem Hibernate/JPA Apache HiveApache Hive Apache SparkApache Spark T-SQLT-SQL RDBMS (MySQL FireBird ORM Liquibase CouchDB Dynamo DB session manager DBeaver Sphinx AWS DynamoDB Flyway Cloud Firestore Apache Spark ML Hadoop (Hortonworks HDP) Hadoop Distributed File System (HDFS) Firebase messaging BigChainDB FireStore SequelizeSequelize dbtdbt Database development Realm SQL Server Management Studio TSQL Typeorm MemSQL Google Firebase PouchDB Neo4j GreenDao Oracle 10g NHibernate PGAdmin MongoDB Compass Databricks CosmosDB SQL Stored Procedures OrmLite Transact-SQL PostGIS InfluxDB pgSQL Couchbase Firebase Realtime Database CockroachDB Raven DB Materialize IBM DB2 MS Access Dbase Foxpro Prisma GORM BoltDB SSMS MySQL Workbench Oracle 12c AWS Database Hortonworks Data Platform (HDP) Apache Spark 2 Redis Cache Oracle 9.2 Oracle DataBase 11g dbForge Studio SSRS MySQL cluster Google BigQueryGoogle BigQuery Django ORM Web SQL SQL Xamarin Relational Databases Pg Admin NPGSQL ELK stack (Elasticsearch, Logstash, Kibana) MS Remote Access Service Oracle 8 Toad PGBouncer NaviCat HSQLDB Apache Druid SQL Alchemy Aura MS SQL Server Management Studio Clickhouse SqlServer Microsoft Azure SQL Server SQL queries Airtable Data Warehousing PSQL Oracle SQL Data Lake Sybase sqlx Data Warehouse Aerospike RethinkDB RQL Sql Anywhere Dbase Paradox Neteeza DB2 SQL Tuning Database Modeler Database Modeling Database Design Database AnalysisDatabase Analysis Database Administration Liqbase SSIS Dapper ORM Doctrine ORM KSQL rrd Slick database query PowerMTA Momentum Quagga Inspections Database ArangoDB SingleStore Apache Kylin RocksDB BerkeleyDB OrientDB Bigtable Jaguar ORM SQFLite Moor ObjectBox SQL Server Analysis Services SSAS YDB RavenDB Erwin Data Modeling Oracle Skin Editor Oracle ADF Various SQL SQL Server Integration Services BQ Spark SQL NoMySQL TimescaleDB

Hosting, Control Panels Arrow

QA, Test Automation, Security Arrow

QA Automation Automated testing BugZilla Capybara CucumberCucumber JUnit Apache MavenApache Maven Mockito RSpec PostmanPostman UI/UX testing QAQA TestNG JasmineJasmine Mocha Appium WebdriverIOWebdriverIO Protractor CodeceptJS SoapUI JMeterJMeter Selenoid Wireshark JBehave Test NG PyTestPyTest MSTest SpecFlow NUnit Espresso XCUITEST Gatling Manual Testing Selenide TestLink Fiddler RestAssured Mantis Firebug Behavior-driven development (BDD) Selenium WebdriverSelenium Webdriver TestComplete Chrome DevTools Functional Testing UI testing Selenium IDESelenium IDE Cypress Allure Unit Testing Testing JestJest React Testing Library Karma Browserstack SauceLabs TestRail Serenity Spock Postman (automation) Burp Suite API testing Hypothesistesting Software testing Test design Charles Proxy WEB testing UI automation tests XCTest Gherkin Nmap MS Test Testing desktop applications Testing mobile applications stress testing regression testing smoke testing GUI testing verification testing validation testing positive/negative test cases bug reports Creating of test case xunit Zeplin TestRails nock Chrome Developer Tool Testing Library Puppeteer TestFlight UIAutomator Percy E2E tests OWASP ZAP Minitest PHPUnit PhantomJS App Tester Ad-hoc testing Cross-browser testing Selenuim Grid REST Assured ReportPortal Newman (Collection Runner for Postman) Test Plan Test Cases QUnit Postmark API Scalatest Use Acceptance Testing frida-tools Mobile Testing Allure Reports Cloud Security Integration Tests Performance Testing Applitools Django unit-tests Django tests Selenium RSpec Test::Unit Cybersecurity Capybara Poltergeist Integration testing Qase Rest-Assured Zephyr Test-NG Newman SpiraTest Data Testing Page Object Model (POM) exploratory testing Playwright Allure Report Serenity Screenplay Serenity Report End 2 end testing Salesforce Testing Test Plans Salesforce Sandbox development and Testing Sitechko Hiptest Katalon non-functional testing Mock CasperJS A/B Testing e2e testing Metasploit WPScan JohnTheRipper Nessus Manual and Automation Testing Load Testing Selenium Library Sanity Testing Compatibility Testing Selenium Grid Fitnesse Lettuce Gauge Loadrunner K6 Web and Mobile testing Selenium Silicon React-testing-library Snapshot tests Nikto web application security Usability tests Golden Tests HockeyApp Equivalence Partitioning Boundary Value Analysis Checklist Based Testing State transition testing Localization testing Decision Table Testing Use case testing Dredd Appium inspector Vysor Mobile automation testing iOS SilkTest Software Testing Life Cycle (STLC) QA Functional/Automation Testing AWS Distributed Load Testing Black-box Testing Installation Testing Configuration Testing Requirements Testing Desktop Testing Automating vulnerability scanners Analyzing vulnerability reports Penetration testing Full-cycle testing of mobile applications Full-cycle testing of web applications Identifying and exploiting vulnerabilities in mobile systems Automated testing techniques Frida Jeb Ghidra Mobile application security threats Blackbox testing Dynamic and static analysis Security testing of web applications and cloud infrastructure OSINT Whitebox testing Vulnerability Assessment Security Code Review Threat Modeling Network Scanning OpenVas Acunetix MobSF Armitage Web Security Mobile Security Fuzzing Yara dnSpy/ilSpy Security Source Code Review MSTG AFL Service Solutions libFuzzer pwntools

SDK / API and Integrations Arrow

AWS API Facebook API Google Maps APIGoogle Maps API Rails API Stripe SwaggerSwagger OAuth Google API JSON Web Token (JWT) Apollo GraphQLApollo GraphQL Zuul Log4j API Sendgrid API Microsoft Azure API LinkedIn API Stripe API PayPal API eBay API Taobao API Cloud based API YouTube APIYouTube API Dropbox API Twitter APITwitter API Telegram API Unsplash API Mapbox API Eslint LinkedIn API Android SDK Canvas 2d browser API Dailymotion API Instagram API IOS SDK SOAP API ASP.NET Web API Web API API testing Android APIs iOS APIs Twilio Jira API ServiceNow API Kotlin Flow Retrofit Hubspot API Salesforce API SharePoint API OpenStreetMap API Twilio API Stripe Payment Gateway Facebook SDK AWS SDK for Android Windows API JSON API Concurrency API Context API Fetch API Hasura Fixer API FastApi Mulesoft RESTful API Apiary Blackberry SDK Stripe payment APIs FB SDK Google SDK Geolocation API Plivo TextMaster APIs ApplePay GooglePay Spotify fast_jsonapi JSP Liferay WebStorm API Insomnia AWS Advertising API Postmark API Mailchimp API PayU API API Callouts AEM Email API AWS MWS (Amazon Marketplace Web Service) SP-API (Amazon Selling Partner API) OpenAPI Google AutoML API DI IP geolocation API AWS API Gateway Metadata API Bulk API iPhone SDK Microsoft Graph API Dynamics API Keycloak Google Maps SDK Stream API UPS Developer Kit API dropbox-sdk windows forms (winforms) Apache POI API Mailgun API Uber API Swagger API Facebook Marketing API Google AdWords Api SurveyMonkey Api ASP Web API Websocket API Office 365 API Open Commerce API OIDC CloudElements Salesforce APIs Slim CD API Reepay API SAP BAPI Linode API Git API Sptripe API Zoho API Bigcommerce API DirectX OpenAIs GPT3 APIs Cassia API Collections API Tsoa Konga Google Places API RestTemplate SocureAPI TrulioAPI ApiGateway Daylimotion Player SDK Elevation API API Integration Magento Cloud API in VBA Platon payment API CloverConnector SDK Autolayout JFree API Goldfish API Swing API Managed Services Hasura GraphQL Streaming API Retail SDK Commerce SDK Parature API CPOS SDK DXVA2 SDL2 MP4Box Mediainfo tstools

Boost Your Product Development with Upstaff.

Work with the largest network of software engineers and independent contractors to scale your project.
Boost Your Product Development with Upstaff.